A GUIDE IN FORENSIC CHEMISTRY

Forensic chemistry is a branch of chemistry that deals with the application of chemical knowledge, principles, and procedures to matters involving civil or criminal law and to all questions where control of chemical compounds, products, or processes is involved.
Forensic Chemistry is an interdisciplinary field of Chemistry tasked to solve cases that can only be explained or resolved by applying analytical methods of investigation and instrumentation with chemistry as the main core of discussion.
Forensic chemistry is a broad and diversified field of science. It includes all branches of chemistry and the application of its principles to solve crimes when it arise in the administration of justice. Significantly, Forensic chemistry is vital in crime detection when the components or chemical composition, structure of physical evidence/s collected from the scene of the crime are needed to support in the speedy solution of crime.
Application of forensic chemistry is legally applied to the following:
1. Primarily, Forensic Chemistry deals in the recognition, identification, preservation, packaging & transportation of physical evidence collected at the crime scene.
2. In crime detection, it is applied in the identification of poisons, blood, semen, feces, urine, saliva, and other body fluids whether fresh or dried. It also include other stains of interests from ob-gynecological origin, mineral stains, fruits and/or vegetable stains.
3. It is involved in determining the kind of ink used in signature writings, and the kind of paper of a questioned document.
4. The knowledge of properties of volatile substance like organic solvents (alcohol, acetone, etc), accelerants (gasoline, kerosene, oils), and miscible materials such as textile fibers from clothing, are applied in forensic analyses of arson cases.
5. Identification of air, land, and water pollutants that may cause diseases are also a part in the field of forensic detection.
6. It ascertains the inorganic and organic components present in physical evidence like soil, rocks, dusts, hair, skin, fibers, etc. which recently had invaded the field of forensic chemistry to assist in crime detection and investigation.
The application of forensic chemistry in crime solving is not only concerned in identifying the chemical components and structure of physical evidence submitted to chemistry section in crime laboratory but it has invaded other interrelated fields in the world of forensic sciences. It assists the Medico-Legal Officers to determine the presence of semen and spermatozoa of smear specimen taken from the victim/s of rape case/s. Drug analysis either prohibited or regulated has also been undertaken extensively along this field. Drugs can be determined whether it contains ingredients or composition not allowed in the eyes of law. Questioned documents that may contain forged signature or original signatures superimposed by another entry are examined employing ink analysis technique. For cases of shooting incident, before the Forensic Ballisticians collects standard sample from a suspected firearm, it shall be handled first by a forensic chemist who will examined analyzed if it had been fired recently. Applying basic principles of properties of common metals, to determine engine or serial numbers or engine of motor vehicles or serial numbers of firearms were tampered or not, and if it is, the original letters and numbers of the engine or serial numbers will be restored employing macro-etching examination. The word forensic is referred to the administration of justice. What is referred to justice is the established physical properties and chemical composition of an evidence its presence and involvement at the time the crime was committed. Further, the identification of properties of these evidence provide information or clue that will associate the presence of the suspect at the crime scene and or link the suspect and the victim before death .
Practices of Forensic Chemistry
The following are the guidelines of crime laboratories on the collection or reception of specimen or evidences to be examined in the practice of forensic chemistry.
1. Sufficiency of samples. Except for only one possible evidence that can be collected at the crime scene, in the body of the victim or in the possession of a suspect, the more the volume or quantity of specimen were found and collected the better it is.
2. Standard for comparison. Trace evidences like hairs, fibers, footprint, soil, etc. when preserved and collected needs standard and control samples for comparison. These are packed in a standard operating procedure on “maintenance and individuality” (SOCO, PNP Crime Lab., 2002). Each specimen should be placed separately in a suitable container and proper markings and label must be indicated on the package such as “Q” for questioned sample, and “S” for standard or control specimen. Each must be properly sealed to avoid loss, tampering & spillage
3. Actual examination of the specimen. The evidences that were identified and collected at the crime scene by the SOCO team are brought to the laboratory for analyses. Each evidence are submitted to the staff duty officer by the time they arrived the crime laboratory. These are then distributed to the respective sections depending upon on which an evidence should be examined. After each are properly received at the different branches in the laboratory, these were then forwarded for examination to respective skilled and experts.
4. Communication of the results of the examination. The findings after the actual laboratory analysis of an evidence, the analysts deduce his/her findings into a laboratory report which will serve as documentary evidence. These are then forwarded to the requesting or investigating agency.

In the practice of forensic chemistry six golden rules are strictly followed:
1. At the crime scene the FOCO (forensic chemical officer) has to go around slowly in order to recognize and identify an evidence. A detailed search along this line can be successful if appropriate search methods/techniques will be used. This will depend upon on the extent of area of the scene of crime.
2. While on the process of locating or finding an evidence, “leave no stone unturned”. All corners at the crime scene, the ins and outs must be thoroughly inspected.

3. Right from the start upon arrival at the crime scene taking notes of the general appearance of the crime scene inside the dwellings and outside must be properly recorded. When evidence are found proper sketches and photographs must be employed following the cardinal rule of documentation in forensic science. The steps “7” and “8” of crime scene processing of SOCO is applied here.
4. There are instances where at the crime scene some experts’ opinions are needed especially when field or screening test are to be conducted. The SOCO team leader decides on this matter. Example is the preliminary test for the presence of blood when stains are found within the perimeter of the crime scene.
5. While on the process of crime scene management all the members of the SOCO officers may use their imagination. This is imagining how the crime was committed. Sometimes reenactment of the crime is facilitated by the experts when time and evidences collected allow the circumstances.
6. During the crime scene processing, by the time a piece of evidence is found, and in the event of possible reenactment avoid complicated ideas that may lead to confusion in the analysis of how the crime was committed. Like for example, looking for a knife or bolo as evidence when the victim died due to a bullet wound of a shooting incident.
Physical Evidence

Recently, the modern technique of crime detection is having crime investigators equipped with sufficient documents, describing physical evidence/s as collected from the crime scene. It includes those identified evidences found in the body of the victim, and suspects wherein SOCO specialists believed has relevance to the case. Ultimately, laboratory reports and testimonies of experts based on the findings of their examinations have played a great impact in the immediate solution of criminal cases filed in court.
Scope of the study of physical evidence: Evidence are precious things in crime investigation. They can be utilized to determine whether a crime had been committed. These are essential elements in criminal justice system not only in the Philippines but predominantly in advance countries. It substantiates and provides assistance to the effectiveness of crime solving even in the absence of an eyewitness during the commission of a crime. Since these are valuable things their worthiness must be internalized. At the crime scene once evidences are recognized and identified, a SOCO (Scene of Crime Operation) team follow the established standard operating procedure in collection, preservation, and packing of evidence/s. Holdings of various evidence in the possession of a SOCO team ratifies the real essence of crime investigation. One of the indispensable factors of handling evidence is its indispensable description from the time it was found and recovered until it was properly packed by the collecting technician so that chain of custody of the evidence is adequately maintained. Proper documentation of these collected evidence/s must be further established by a SOCO member to the evidence custodian from the time the evidence was identified and collected up to the time it is submitted and examined in the crime laboratory. It is very important that tangible evidence/s shall subscribe as described from the time it was discovered, up to the time it is presented in court. Significantly appropriate documents of these various types of physical evidence/s may provide a link that a person (particularly a suspect) was present at the crime scene at a particular period of time, and that the same can ascertain a linkage between the suspect and the victim. Accomplishing these factors will strengthen a case filed in court by the investigator.
Physical evidence is very essential to criminal investigating agencies. Holdings of these had supported significantly to a speedy solution of numerous crimes. When evidences are recognized, identified, collected, and properly preserved with appropriate packing based on the standard operating procedure from both the Philippine National Police (PNP) and National Bureau of Investigation (NBI) and submitted to these laboratories for examination, the laboratory findings assist the courts in their analysis towards unprejudiced decision. Presentation of these evidences in court simultaneously with testimonies of laboratory examiners can illustrate how a crime was committed. Majority of physical evidences gathered by SOCO team are confronted as to the identification of its chemical composition and components. When such is the inquiry basic principles of chemistry enters the phase of investigation.
The core of the study of forensic chemistry is the involvement of physical evidence found and collected from the crime scene. It also include evidence found in the body of the victim, suspect and in his environment. There are several definitions of “evidence”. In this hand-out each definition is dealt with. Evidence as defined shortly, is a proof of allegation because they are “silent witness” during the commission of the crime thus it is defined as a proof of allegation.
Evidence is a means sanctioned by law, of ascertaining in a judicial proceedings the truth respecting a matter of fact. (Sec. 1, Rule 128, Rules of Court, Penal Code of the Philippines). Physical evidence encompasses any and all objects that can establish that a crime has been committed or can provide a link between a crime and its victim or a crime and its perpetrator (Saferstein, R. 2001). These evidences can be anything like small pieces of broken glasses, latent fingerprints, soil, rocks, vegetative matter, blood (dried or fresh), paint chips, bullets, documents, hairs, fibers, firearms, knives and many others.
Long before, small objects or materials which has no relevance and of no importance during the process of crime investigation had already played a marginal impact on the outcome of criminal trials when these were considered and presented as physical evidence. The advanced modern technologies in the last couple of decades have contributed a great success in the field of crime investigation through valuing physical evidences. It became a major source of relevant information of investigation and adjudication of criminal cases. Being totally objective in nature (unlike witnesses, prone to human error and bias), physical evidence offers facts of truth about past events because evidence is a “silent witness” that never lies. “THERE IS NO SUCH THING AS A PERFECT CRIME. THERE IS ALWAYS A CLUE. WE JUST NEED TO INVESTIGATE TO COME UP WITH AN EVIDENCE THAT WILL UNCOVER THE TRUTH”.

Physical evidence can be of use in determining that a crime has been committed.
What is an evidence?
Evidence is a proof of allegation. It is a means sanctioned by law, of ascertaining in a judicial proceedings the truth respecting a matter of fact. (Sec. 1, Rule 128, Rules of Court, Penal Code of the Philippines).
What is an object or real evidence?
Objects as evidence are those addressed to the sense of the court. It may be exhibited to, examined or viewed by the court, (PNP-SOCO, 2002). In order to understand how evidence can link a suspect to a crime, it is important to understand the distinction between class and individual characteristics of evidence. Physical evidence is separated into two general categories; evidence with individual characteristics and evidence with class characteristics.
Evidence that has individual characteristics can be used to identify a specific suspect and link that suspect to a particular crime. Some of the better known examples of individual evidence are fingerprints, palm prints, and footprints.
Class characteristics are common to a group or class objects. Common examples of evidence with class characteristics are fibers and other items that can be placed in a general category, such as oil found at a crime scene that leaked from crankcase of an engine and soil transferred to or from a crime scene. DNA evidence as of this time is still described as evidence with class characteristics with decisions about identity being based on statistical probability.
When is evidence admissible in court?
Evidence is admissible when it is relevant to the issue and is not excluded by the law or by the Rules on Evidence. Evidence must have such a relevance to the fact in issue as to induce belief in the existence of non-existence. Evidence on collateral matters shall not be allowed, except when it tends in any reasonable degree to establish the probability or improbability of the fact in issue (PNP-SOCO, 2002).
Common types of Physical Evidence:
1. Blood, semen, and saliva. All suspected blood, semen, or saliva. These kind of evidence can either be in liquid form or in dried state conditions. Further, these evidence could either come form animal or human origin whose presence in any form suggest a relation to the offense or persons involved in a crime. This category includes blood or semen dried onto fabrics or other objects, as well as cigarette butts that may contain saliva residues. These substances are subjected to serological and biochemical analysis for determination of identity and possible origin.
2. Documents. Any handwriting and typewriting submitted so that authentically or source can be determined. Related items include paper, ink, indented writing, obliteration, and burned or charred documents.
3. Drugs. Any substance seized in violation of laws regulating the sale, manufacture, distribution, and use of drugs.
4. Explosives. Any device containing an explosive charge, as well as all objects removed from the scene of an explosion that are suspected to contain the residues of an explosive.
5. Fibers. Any natural or synthetic fiber whose transfer may be useful in establishing a relationship between objects and/or persons.
6. Fingerprints. All prints of this nature, latent and visible.
7. Firearms and ammunition. Any firearm, as well as discharged or intact ammunition, suspected of being involved in a criminal offense.
8. Glass. Any glass particle or fragment that may have been transferred to a person or object involved in a crime. Windowpanes containing holes made by a bullet or other projectile are included in this category.
9. Hair. Any animal or human present that could link a person with a crime.
10. Impressions. This category includes tire marking, shoe prints, foot prints, depressions in soft soils, and all other forms of track. Glove and other fabric impressions, as well as bite marks in skin or foodstuffs, are also included.
11. Organs and physiological fluids. Body organs and fluids are submitted for toxicology to detect possible existence of drugs and poisons. This category includes blood to be analyzed for the presence of alcohol and other drugs.
12. Paint (wet) & paint chips. Any paint, liquid or dried, that may have been transferred from the surface of one object to another during the commission of a crime. A common example is the transfer of paint from one vehicle to another during an automobile collision.
13. Petroleum products. Any petroleum product removed from a suspect or recovered from a scene. The most common examples are gasoline residues removed from the scene of an arson, or grease and oil stains whose presence may suggest involvement in a crime.
14. Plastic bags. A polyethylene disposable bag such as a garbage bag may be evidential in a homicide or drug case. Examinations are conducted to associate a bag to a similar bag in the possession of a suspect.
15. Plastic, rubber, and other polymers. Remnants of these man-made materials recovered at crime scenes may be linked to objects recovered in the possession of a suspect or perpetrator.
16. Powder residues. Any item suspected of containing firearm discharge residues. Serial numbers. This category includes all stolen property submitted to the laboratory for the restoration of erased identification numbers.
17. Soil and minerals. All items containing soil or minerals that could link a person or object to a particular location. Common examples are soil embedded in shoes and some adheres unto safe insulation, while others are found on garments.
18. Tool marks. This category includes any object suspected of containing the impression of another object that served as a tool in a crime. For example, a screw driver or crow bar could produce tool marks by being impressed into or scraped along a surface of a wall, or on metallic surface.
19. Wood and other vegetative matter. Any fragments of wood, sawdust, shavings, or vegetative matter discovered on clothing, shoes, or tools that could link a person or object to a crime.
20. Gunpowder residue. These are particles either visible or in microscopic size which are usually found in the clothing, or hairs of the victim of shooting incident.
Before submitting the evidence to the laboratory, the following checklist should be conducted: (The answer to each questions should be yes).
1. Did I collect all the available evidence in this case?
2. Did I collect sufficient amount of each type?
3. Was I careful not to alter the material in handling and in preparing it for transmittal to the laboratory?
4. In packing:
a. Did I properly label each piece of specimen individually and make references that I can identify later?
b. Did I wrap the various specimens separately to prevent contamination?
c. Did I pack the specimen properly?
d. Did I use a clean container for the specimen?
e. Did I secure properly the specimen in the container?
f. Did I seal it in such a manner as to prevent its being spilled opened by accident?
g. Did I address the package properly?

Class characteristics are common to a group or class of objects. Common examples of evidence with class characteristics are fibers and other items that can be placed in a general category, such as oil found at a crime scene that leaked from the crankcase of an engine and soil transferred to or from a crime scene. Proper handling of physical evidence is essential and very important to obtain the maximum possible information upon which scientific examination shall be based and to prevent exclusion as exhibit in court. Specimen which truly represents the material found at the scene unaltered, unspoiled or otherwise unchanged in handling will provide a better information upon examination. Legal requirements make it necessary to account for all physical pieces of evidence from the time it is collected until it is presented in court.
Questions asked when is the time an object becomes an evidence and admissible in court? Objects as evidence are those addressed to the sense of the court. It may be exhibited to, examined or viewed by the court, (PNP-SOCO, 2002). Evidence is admissible when it is relevant to the issue and is not excluded by the law or by the Rules on Evidence. Evidence must have such a relevance to the fact in issue as to induce belief in the existence of non-existence. Evidence on collateral matters shall not be allowed, except when it tends in any reasonable degree to establish the probability or improbability of the fact in issue (PNP-SOCO, 2002).
Evidence are varied according to the following:
1. Direct or ordinary evidence – an object/material or substance that is tangible to which our senses can perceive it. It can either be found or discovered at the crime scene, in the position of the suspect or found within the body of the victim.
2. Corroborative evidence – a kind of evidence that seeks and confirms verified and proved facts through scientific knowledge in order to establish a conclusion. Example is paraffin casting. When forensic analysis provides information that the paraffin cast is positive of nitrates of gunpowder residue, the laboratory report and the testimony of the expert becomes a corroborative evidence.
3. Circumstancial evidence – a kind of evidence that is sufficient to produce conviction if there is more than one circumstancial facts from which the inferences are derived and proven, and the combination of such is enough to produce conviction beyond reasonable doubt. For example, if a dried stain on a piece of cloth is suspected to contain blood, and that after chronological forensic analyses provided information of blood’s presence and that it belongs to human origin particularly of blood type “O”. Out from the single evidence submitted, the scientific data supplied from a series of forensic analyses eventually became a circumstantial evidence. When such evidence and laboratory reports are presented in court and were supported by the expert through his/her testimony stipulating the events how a single evidence was examined revealing such results illustrates a conviction beyond reasonable doubts.
4. Trace evidence are evidence which are microscopic in nature. . These are trace materials that were left on either side after a contact between objects and or people involved with a crime or present at a crime scene. Trace evidence can also be minute material from the scene and or victim. Such evidence may be used in the reconstruction of the crime or as a proof that the suspect committed some criminal act. These substances are body fluids, paint, glass, fibers, hair, soil, plant debris, and cosmetics.
5. Associative evidence – are physical evidence which are used as tools for reconstructing a crime scene that will generally locate evidence that can be used to associate or disassociate a suspect to a crime. Example are hairs, fibers, blood and other body fluids. Included also are paint, glass, firearms, bullets, fingerprints, footwear impressions and other evidence.

Significance of Physical Evidence in Crime Detection
Crime laboratories as a tool to assists in the speedy solution of crime is useless without physical evidence to examine. Physical evidence must be handled and processed in a way that prevents any change from taking place between the time it is removed from the crime scene and the time it is received by the crime laboratory (Saferstein, 2001). The experts identify first the chemical identity of a substance aided with the existing analytical techniques then compare this to a standard sample. They do this many times until they are convinced and satisfied for a positive identification of the unknown sample.
Physical evidence can be used in criminal investigation in variety of ways:
1. Associating or disassociating persons with crime.
2. Determination of time when the crime was committed.
3. Locations and instruments of the crime.
4. Aid in reconstruction of the crime.
5. It can prove to be of no value.
Evidence in criminal investigation is any item or object that helps to establish the facts of a related crime. Evidence may be found at the scene of the crime, in the body of the victim, in his/her surroundings or any object which has relation to the crime that were in the possession of a suspect and in his environment. These evidences can be anything like small pieces of broken glasses, latent fingerprints, soil, dust, rocks, vegetative matter, blood (dried or fresh), paint chips, bullets, documents, hairs, fibers, firearms, gunshot residue, knives and many others. .

Handling of evidence means, recognition, identification, collection, preservation & transportation of evidence. Proper handling of physical evidence is essential and very important to obtain the maximum possible information upon which scientific examination shall be based and to prevent exclusion as exhibit in court. Specimen which truly represents the material found at the scene unaltered, unspoiled or otherwise unchanged in handling will provide a better information upon examination. Legal requirements make it necessary to account to all physical pieces of evidence from the time it is collected until it is presented in court. At the crime scene, the forensic experts/technicians (SOCO) will go around and check the entire perimeter of the crime scene, this is to familiarize the area and to recognize things, small or tiny objects which they will soon recognized as possible evidence that may have relevance to the crime. After the recognition of evidence, these are identified of its connection on the probability whether it came from the victim or from the suspect. Proper collection and preservation of evidence sequentially follows the standard operating procedure.
Physical evidence at the crime scene once recognized, and identified, before these are handled by the technicians, it is photographed in its location, simultaneously this is supported by the sketcher reflecting the exact position and location of the evidence on the area of concern. This is done as part of documentation. The technician, immediately writes all the features of the object on the evidence tag at “description of evidence” portion before the item shall be preserved and packed. Evidence tag is an “evidence format” brought at the crime scene, and is one of the important documents when handling physical evidence. Evidence tag is the same as a record book where all the brief entries of relevant information of the case are entered. One of the main parts of evidence tag is the “description of evidence”. Describing an evidence shall be written in a paragraph form. It should include all the visible features, the condition and location of the object, in brief but concise manner. Vivid description of the evidence is essential so that in the absence of a photograph, by just reading the description, the reader can picture in his/her mind its utmost appearance. A realistic description of an evidence plays a great role as part of chain of custody, most especially at the time when this is presented in court. The evidence should bear the same description as written in the evidence tag by the technician who collected it from the scene of the crime until it is presented in court as exhibit. Besides, the essence of proper description of evidence prevents the events of substitution when one is interested of the case in order to conceal or destroy it.

Describing Physical Evidence:
Describing physical evidence is an essential part of the documentation of evidence at the crime scene. The following are guiding principles and mechanics on describing evidence found and recovered at the crime scene.
1. When an evidence is found and recognized at the crime scene, the cardinal rule is take a photograph, sketch where it is located with corresponding dimensions.
2. The description of an evidence, shall be written in a paragraph form.
3. The entry shall contain all the condition and other properties of the evidence.
4. If several evidence are found and recovered inside a container, described first the entire container, then take out each evidence, and described separately.

Maglaque, (2008).The mechanics of Describing Evidence.

5. The description of evidence starts with the number of object/s, written in words followed by the numerical value enclosed in parenthesis. Example: One (1) 0.38 cal. pistol. Seven (7) strands of suspected black human hairs. One (1) stainless kitchen knife with black hard plastic handle, measuring 8 in. from the tip of the blade up to the handle.
6. State where the evidence is found. Mention the specific area where it is located at the crime scene. This should be supported by a photograph, notes and sketches particularly the position of the object or pattern and shape of evidence like blood, urine saliva, and other similar fluids. Example: Seven (7) strands of alleged black human hairs on the right hand of the dead body of the victim.

7. For solid evidence:
a. Specimen with definite shapes like, chairs, carton or box, documents, floor tiles, bed, bed sheets, specify the dimensions which can be measured by a steel tape, ruler or other measuring device available. Example: One (1) empty box of “Nestle, Bear Brand Powdered Milk”, measuring 18in. by 14 in. by 6in.
b. Solid objects with irregular shape like pieces of wood, stone or rocks, may be described for its color, length, and weight. Example: One (1) piece of off-white rock (limestone) approximately weighing 6.5 kgs.
c. Objects like glass, jar, bottles, if these are intact with no broken parts, the standard size based on manufacturers designation may be mentioned. However, for open glasses, the outside diameter of the mouth can be obtained by means of a Vernier caliper meter. Example: one (1) green wide open mouth jar without cover.

8. Liquid evidence:
a. Describe the container whether, plastic, glass bottle, or transparent jar, or amber (brown). If liquid evidence are inside a bottle or jar (glass or plastic) mention specifically if a cover is present (metallic, or plastic cap, etc) that secured the content. If a label is found on the container (bottle) of unknown liquid, this must be mentioned. In the absence of label, the production number or the logo of the company which are usually located at the bottom part of the bottle shall be looked into and shall be entered in the evidence tag. The company’s logo shall be sketched, or photographed.

The mechanics of Describing Evidence.

b. Approximate the volume of the unknown liquid inside a container. However, if the volume of liquid evidence are contained in large container such as drum, a measured quantity (using graduated cylinder), shall be taken, and this will be placed inside a separate sterilized clean and dry container with appropriate cover to avoid spillage.
The volume shall be reflected as part of the description of the evidence. However, if the liquid sample are recovered and collected by means of other container with unspecified volume, this must be described accordingly. For example, a cupful of blood taken from the floor near the body of the victim. It can also be stated this way; a table spoon of blood scraped from the kitchen floor, placed inside a transparent glass, covered with paper, and further secured in a rubber band. The same technique shall be done on similar body fluids sample like urine, saliva, and other liquid specimen.
c. It is also important that the color of the unknown liquid shall be mentioned. In addition, the consistency of the liquid whether it is a suspension like medicine syrup, sticky liquid like catsup, mayonnaise, oil, gel, and other similar solution or colloid substance.
Example: Two (2) blue juice glasses, one containing unknown colorless liquid approximately 15 mL., the other half filled with yellowish unknown colloid approximately 75 mL

9. State and describe the kind of packaging or the container where the evidence was found or contained. It is very necessary that the dimension of the package like carton be obtained especially if a major evidence like dried blood stain, or dried semen is found. Dimensions of the container can be measured either a steel tape, tape measure or any available measuring device. Example: same as in sample “a” of solid evidence.
10. State the manner the evidence was packed such as placed inside a cellophane twice. State the style it is sealed, (mention here whether it is stapled how many times, or sealed through scotch tape, glue or ordinary paste). Example: One (1) transparent cellophane containing one (1) apple brand spring notebook folded twice and sealed with (6) staple wires.
11. State whether the object is hard solid object, (ex. made of metal or wood ), in powder form, granules, or if in liquid state (ex. syrup), or gas.

The mechanics of Describing Evidence.

12. State the color, and specific shape like (square, rectangle, oval, oblong, irregular or regular, etc.), and size (whether large medium small, big, long, tiny, etc).
13. State whether a label could be found on the package of the container of the evidence. These can be serial numbers, company’s logo, where is it made of, the name of a manufacturing company, or the production number if available.
14. State whether a label could be found on the package of the evidence such as serial numbers, production numbers, where it is made of, and or manufactured by a certain factory (write the name of the company).

15. In case of large quantity of powder or granules form of evidence like flour, or similar items, after it has been photographed and sketched, its big container shall be described. If the entire object shall not be send to the laboratory, a representative sample will be taken and the container where it will be secured shall also be described appropriately and accordingly.

The Evidence Tag
Evidence tag is one of the documents in handling physical evidence. This document format is brought along with the evidence technician at the crime scene. Within the paper tag, several segments can be found where all the pertinent information of the case are entered. Whenever a piece of evidence is found at the scene of the crime, its description is immediately written in the evidence tag on the portion intended for it. The rest of the pertinent information about the case are also written in the evidence tag such as: type of offense (entries here shall all be written with “alleged” before the specific case is mentioned), name and address of victim/s and suspect/s (if available), time and date (at the crime scene), location of the crime, description of evidence, specific location where the evidence was found, name and signature of the technician collecting the evidence, and names of at least two (2) witnesses at the time the evidence was collected and their signatures.
Once a specific evidence were preserved and properly packed, the evidence tag containing all the information of the case, becomes part of the evidence. Therefore, it shall also be preserved so that the entries written in ink will not be damaged. There were cases, where the label of the container, particularly of liquid evidence are wet or prone to absorb moisture, never attach directly the evidence tag. There is danger that all the entries in ink might be contaminated. In some instance, there were liquid evidence that were improperly packed, then spillage is susceptible. Secure the evidence tag inside a cellophane so that even if small quantity of the liquid evidence is spilled, the written information of the case will not be contaminated. In solid objects, evidence tag can be attached directly on the packaging. Nevertheless, this must be sealed properly. Preferably this shall be secured by a scotch tape. As part of the standard operating procedure at the crime scene, once an evidence has been completely preserved and packed, together with its evidence tag, this is submitted to the evidence custodian. The custodian records all the entries written in the evidence tag., and this entry is one of the permanent records kept by the evidence custodian as part of chain of custody of evidences collected from the crime scene. The same document shall be presented in court when chain of custody is needed.
Sample of entry of pertinent information of an “Evidence Tag”, & “Describing the Evidence”. Case: Alleged Suicide
Victim/s Name & Age: Rosy Roces ( 18 yrs old) Address: 16 A, Luna St., Barangay Bora, San Pablo City Location of Crime:
ABS CBN Studio, Lim Ket Kai Mall, Cagayan de Oro City
Suspect: Unknown Time & Date: 2100H 27 November 2007 Description of Evidence:
One (1) stainless serrated blade kitchen knife with black hard plastic handle, measuring six (6) inches from tip of the blade to edge of the handle, with suspected dried blood stain on one side of the blade.

Location where Evidence was found:
Evidence found on the right hand of the dead body of the victim Name of Technician collecting the Evidence: Insp. Gregorio M. Pimentel Jr. Signature:
Name & signatures of witnesses at the time the Evidence was collected:
1. PO1 James C. Calabasa Signature:
2. Mr. Christopher N. Ssntos Signature:

Maglaque, (2008). The elements of “Evidence Tag” .

Reception of Specimen: This is referred to evidences/specimen received in the laboratory for examination. When specimen or physical evidences are submitted and received in laboratory for examination the duty officer immediately registers the pertinent data in the record book. In the logbook, it shall indicate the following;

a. time and date received
b. name of the bearer of the evidence
c. requesting party or name of the investigating agency
d. nature of the articles and details of all identifying marks that is present in the specimen
e. the manner the specimen are packed whether in a bottle, paper bag, plastic cellophane, and or any container the evidence is placed inside.
There is a difference in describing the evidence received from when it was found at the scene of crime. There were situations and incidents where the evidence recovered were not inside a container. When this is collected it is placed in a suitable container with an evidence tag. Therefore, when same is submitted to the laboratory for examination, the manner it was preserved and packed shall be indicated in the record book. When all the pertinent entries of evidence are recorded, the duty officer should take no chance of opening it unless the expert examiner for that particular/kind of evidence is present and allows you to do so. If the articles received are badly or inadequately packed, or marked, or insufficiently secured or sealed, proper notations should be made in the registry book by the officer receiving it. In this connection, the receiving officer must call the attention of the bearer and its requesting party so that necessary corrections must be made at once and improvement in this respect will be taken cared of. Information to be entered concerning the evidence includes:

a. package description
b. label information
c. description of evidence
d. any other item of evidence in the same package
e. case number and item number
f. date and name of duty officer and technician

The mechanics of Describing Evidence.

Practically, the above-mentioned items mentioned as evidence yielded significant results from scientific examination in ascertaining the nature and circumstances of a crime. Results of analysis of these evidences are undertaken in crime laboratories on the basis of identification or comparison purposes with the unknown or “question” and “standard” or control specimen. Identification has its purpose, it is the determination of the physical or chemical identity of a substance with the nearest and absolute certainty. Employed in the analysis are variety of analytical methods in crime laboratories. These include spectrometry instruments, color reactions, spot tests, microscopy, chromatography, and many others.
The examination of physical evidence by forensic scientists are usually undertaken for
Identification or comparison. These are identification and comparison. The purpose of identification is the determination of the physical or chemical identity of a substance at a near absolute certainty as existing analytical techniques if allowed and if instrument is available. Forensic analysts are confronted as to the chemical composition of an evidence, example the presence of drugs like shabu (poor man’s cocaine), or marijuana from a seized drug. Identification of blood, hair, or wood for its origin or species as a matter of routine in crime investigation.
Identification process of evidence requires scientific data as basis for conclusion. For example if an investigator wants to ascertain that a particular suspected powder is shabu, the test results on the powder must be identical to those that have been previously obtained from a known shabu sample. The examination must be comprehensive enough to exclude other substance of similar composition. Each type of evidence requires different tests, and each test has a different degree of specificity that one substance is conceivably identified satisfactorily from the others. There are several identity of substances which are included in the library of some sophisticated instruments like FTIR, AAS, GC, where comparison is made easy.
Comparative examination is a forensic analysis which allow both the suspected specimen and control sample to undergo the same tests under the same conditions. The ultimate purpose is to determine whether or not they have a common origin or have come from the same source. This is usually done under a comparison microscope. Results of these tests would allow the examiner to give his expert opinion that a suspect was at the crime scene at that particular location by rendering his analysis on the basis of similar properties of a fiber found at the crime scene with the fibers taken from the suspect’s possession.
In forensic comparison examination, two objectives must be attained. First step is to choose selected common properties from the suspect and control specimen for comparison. The number of properties selected should be identical to the type of materials the two specimen are made of. Second objective is the conclusion in the report rendered by the examiner with respect to the origins of the specimens. It may answer the question; do they or do they not come form the same source? In the event that one or more of the properties selected for comparison do not agree, then the analyst may render his/her findings that the specimens could not have originated from the same source.
Laboratory findings of a forensic analyst stating that both the suspected specimen and control sample came from a common source is said to possess individual characteristics. Evidence that can be associated with a common source in a high degree of probability is said to possess individual characteristics. Example of this are the comparison of random striation markings on bullets or tool marks, the comparison of irregular and random wear patterns in tire or footwear impressions, the fitting together of the irregular edges of broken objects, or matching sequentially made plastic bags by striation marks running across the bags. Individual characteristics is that properties of evidence that can be attributed to a common source with an extremely high degree of certainty.
Class characteristics is a property of an evidence that can associate its source from a group and not from a single source. For example blood as evidence has a class characteristics. If two blood specimens are compared, it can be of human origin, and are blood type as “A”. The value of class physical evidence lies in its ability to provide corroboration of events with data that are as nearly as possible free of human error and bias.
Scientific Evidence is defined as the means sanctioned by law, of ascertaining in a judicial proceeding the truth, respecting a matter of fact, wherein scientific knowledge is necessary. Such scientific evidence must be relevant and correspond to the substance of the issue, and must not excluded by the Rules of court.

Forms of scientific evidence:
1. Real or autoptic evidence – it is that evidence which is addressed to the sense of the court. 2. Testimonial evidence – An expert may be placed on the witness stand and answer all questions asked by both parties in the case. 3. Experimental evidence – An expert witness may be required to perform certain experiments to prove a certain matter of fact. Sometimes may not allow this kind of evidence. 4. Documentary Evidence- Any written evidence presented by an expert in court which is relevant to the subject matter in dispute and not excluded by the Rules of Court. Formal written report, expert opinion, certificates, and disposition are included in this group.

Trace Evidence
According to Edmond Locard a French scientist, and one of the pioneers in forensic science posited the principle known as the Locard’s Exchange Principle”. He said, that when an individual enters an area, it is impossible for him not to take dust particles from the scene. In related manner, he described further that when two objects (hard) come into contact, each of the object will leave particles of one unto the other. Moreover, there are situations where after two hard objects came into contact, each will leave striation marks, or a transference may occur between the two. This means that some parts of one object may transfer into the other object signifying tracing marks as evidence. From these phenomena, started the foundation of forensic studies known as “trace evidence”.
Tracing evidence is the examination and analysis of small particles in order to help establish a link between a suspect and a crime scene or a suspect and the victim of a crime. These small particles or known as trace evidence are dried blood and semen stains, hairs, paints, glass and glass fractures, fibers, explosives evidence, gunpowder residue, firearm discharge residue, cartridge residue, tool marks. Considered and included also are flammable substances in arson investigation, fingerprints, footwear or shoeprints impressions, and “fracture matches’, like automobile headlamps, taillights, etc.
“Fracture matches” can associate a suspect to a crime. For example glass fragments found at the crime scene, when large pieces of these samples are available it is useful in linking a suspect with the crime scene through “fracture matches”. This is when a large piece of glass found associated with the suspect, can be physically fitted with one or more pieces from the crime scene. However, when an individual gains access to a business or house by breaking glass the perpetrator will acquire very tiny pieces of glass on his/her clothing. These cannot be physically matched due to their tiny size, but these pieces can be characterized under the microscope. After proper gross and low power microscopic examinations the small pieces of glass can be characterized by using microscopic “refractive index” analysis. Refractive index is a measurement of how light is “refracted” (bent) as it passes through the microscopic glass sample. Glasses have different formulations and used for different purposes have different “RI’s”. Therefore samples can be compared to determine if the glass from the crime scene could be the source of the glass removed from the suspect’s clothes. Perpetrators who enter into dwellings or business enterprise buildings, residential houses have potential of acquiring small paint samples during their illegal visit. In car accidents, when car collides with a truck or person, there is a significant chance that paint from either vehicle will transfer to the other, and or the paint of the car will transfer to the clothing of the victim of hit-and-run case. These samples can be tested though they may be pinhead in size. Initial tests on this include low power magnification (microscopic) to determine color, paint layer sequence and overall texture. If the questioned and known paint samples appear the same, analytical chemical examinations including solubility tests, and instrumental examination is performed.
When arson investigators are called to the scene of fire one of their foremost methods to determine is whether this suspicious fire was deliberately started. Initial steps would be taking samples from the burned scene and submitting these to a crime laboratory. The burned samples are placed in an airtight cans or container with suitable tight cover. In the laboratory the extracts are analyzed using sophisticated and very sensitive instrumental techniques. The laboratory examiner intends to determine the presence of petroleum products or residue even with a very minute quantity of less than one micro liter (0.00004) which are possibly left within the debris taken from the scene. The major technique for detecting flammable residues is headspace gas chromatography (GC). Heating the sample in an oven causes vapors to be liberated. After several step process the material is injected onto the GC/MS. The resulting chromatogram yields a profile of the volatile components. Specimens like hair is examined grossly, and with both low power and high power microscopes to determine if questioned hairs, found at the scene or on the clothing of an individual are consistent in characteristics to known hairs collected from the suspect and or victim. Some of these characteristics include more obvious traits such as color, length, and morphological shape. Microscopic characteristics of hairs such as the cuticle, cortex, and medulla, which are the three basic components of hair provides significant information. A hair cannot be linked specifically to an individual through these methods but vital information developed as to who the suspect may be and significant elimination of other suspects can often be done.
There are hundreds of varieties of physical evidence commonly submitted for examinations for forensic science laboratories by law enforcement agencies. Biological evidence of this category includes blood of human or animal origin, semen, saliva, urine, hairs with follicles, bones, other organs and skin tissue. These are submitted to the laboratories for purposes of identification and characterization according to genetic factors such as izoenzymes and DNA profiles. Other types of biological evidence such as tears, perspiration, serum, and other body fluids without nucleated cells are not amenable to DNA analysis. Samples of blood, or urine submitted for determination of the presence of drugs, alcohol, or poisons are not included for DNA analysis. When collecting any type of body fluid or tissue, the universal precautions for body fluids should be taken. Wear gloves anytime these specimens are handled and additional protective equipment when appropriate. All body fluids and tissues must be assumed to be infectious regardless of the source.
Organs and physiological fluids. Body organs and fluids are submitted for toxicology to detect possible existence of drugs and poisons. This category includes blood to be analyzed for the presence of alcohol and other drugs. Evidences that could be subjected for DNA analysis are generally limited to substances that are biological in nature. The following are the materials included for DNA examination which have been successfully isolated by crime laboratories: blood and blood stains, semen and seminal stains, saliva and buccal swabs, hairs with follicles, tissues and cells, bones and organs. When collecting any of these body fluids or tissue, the universal precautions for body fluids should be taken. Wear gloves anytime these specimen are handled and additional protective equipment when appropriate. To attain successful DNA analysis on biological evidences recovered from a crime scene depend so much on how these are collected and preserved. In addition, proper documentation is critical. This will start from the time the evidences are found, collected, packed and how these are preserved. Because of its biological in nature, deterioration may occur easily. Any ill effects on the process will seriously affect the outcome of DNA typing. Documentation is important from two points of view in forensic science; the legal process and the scientific one. It must be bear in mind that every major piece of evidence should be documented. At the crime scene, the evidence must be photographed first before it is touched, moved or collected. Note the location and condition of the evidence. Note and sketch relationships of the evidence relative to the crime scene and other objects present. Note and sketch the condition of the biological evidence. Guidelines when biological evidences are received at the crime laboratory: Note the package, label, seal condition and exhibits. Initial the package with unique identification marking the laboratory case number and date. Check the exhibit number and compare with the submission request to insure that the correct item is being received. Note sketch or photograph, the contents of the evidence item. Check the item against the submission request to insure that the description of the item is correct. Photograph, sketch or note the location and condition of biological evidence prior to any sampling. If nay preliminary testing is done, record the nature of the test and the result obtained. Always wear gloves to avoid any contamination. Biological Evidence: Blood and other body fluids. Evidence in this category includes blood of human or animal origin, semen, saliva, urine, and skin tissue submitted for the purpose of identification and characterization according to genetic factors such as isoenzymes and DNA profiles. These are called biological evidence. However this does not include samples of blood or urine for determination of presence of drugs, alcohol, or poisons. These are referred to toxicology section of forensic science.

Blood Evidence
A. Liquid Blood samples
1. Blood that is in liquid pools should be picked up on a gauze pad or other clean sterile cotton cloth and allowed to air dry thoroughly at room temperature.
2. Do not dry the blood stained materials directly under the sunlight or with the use of electric fan.
3. They should be separately placed in a paper bag and brought to the laboratory as quickly as possible. Delays beyond forty eight (48) hrs may make the samples useless for examinations.
4. Bring along with the stained questioned material unstained portion to serve as control in the analyses to be conducted.
B. Dried Blood Stains
1. When found on clothing, if possible, wrap the items in clean paper (ex. Unused manila paper), place the article in a brown paper bag or box and seal and label the container. Do not attempt to remove stains from the cloth.
2. If found on small solid objects, send the whole stained object to the laboratory, after labeling and packaging.

3. Whenever these are located on large solid objects, cover the stained area with clean paper and seal the edges down with tape to prevent loss or contamination. If it would be impractical to carry and or deliver the whole object to the laboratory, scrape the stained onto a clean piece of paper which can be folded and placed in an envelope. Collect also an unstained portion of specimen which will serve as control.
4. Never scrape dried blood stain directly into an evidence envelope. Scrape blood from objects using a freshly washed and dried knife or similar tool. Wash and dry the tool before each stain in different location is scraped off. Seal and mark the envelope with the pertinent data of the case.
5. Never mix dried blood stain in one container. Each must be packed separately and label properly. Do not attempt to wipe dried blood stain from an object using a moistened cloth or paper. This can only be possible if the cloth is clean and sterilized and wet with distilled water to be sure of no foreign substance that may contaminate the stain. C. Seminal Stains
1. Seminal stains found on clothing, blankets and bed sheets must be air dried under room temperature.
2. Wrap the air dried seminal stains in paper envelope and package these in paper bag.
3. Never use plastic bag neither cellophane in packing.

D. Hair Strands
1. Have the person from where the hair strands are collected, bend over a large sheet of clean paper, rubbing or massage using their hands through the hair so that loose hair will fall out on the paper.
2. More hair should be gathered by plucking them from representative areas all over the head using the finger or tweezer. A total of 50-100 hair strands with roots is desired.
3. Do not cut the hair. In rape cases, the victim’s pubic region should be combed prior to collecting standards at least 30-60 pubic hairs are required.
4. Obtain known hair samples from the victim, suspect or any other possible sources for comparison with unknown specimen.
5. The same method may be used to collect hairs from other parts of the body. When the person is a suspect, hair should be gathered from all parts of the body even though there may be an interest in hair from the head at that particular time.
6. If hair is attached such as in dry blood or caught in metal or a crack of glass do not attempt to remove it but rather leave hair intact on the object.
7. If the object is small, wrap it and seal it in an envelope.
8. If the object is large, wrap the area containing the hair in paper to prevent loss of hair during shipment.

E. Fibers
1. If threads or large fibers are found they can be picked up with the fingers and placed in a paper packet which in turn is placed in another paper envelope which can be sealed and marked.
2. Never place loose fibers directly into a mailing envelope since they can be lost from this type of envelope.
3. If fibers are short or few in numbers and if it is possible to do so, wrap the area or the entire item containing the fibers in paper and send the whole exhibits to the laboratory.
4. When fibers or threads are recovered, always send all clothing of persons from which they might have originated to the laboratory for comparison purposes.

F. DNA Evidence: Biological samples for DNA Analysis (DNA Section, NBI, 2000)
The following is a list of biological materials from which DNA has been successfully isolated and analyzed:

Samples Quantity a. Whole blood/blood stains 1-2 mL/gm b. Saliva/Buccal Scrapings 4 cotton buds c. Semen/Seminal Stains 3 swabs d. Urine (only possible if nucleated cells are included) 100mL e. Hairs with Follicles or Root 2-5 pcs f. Muscle Tissues and Cells 15 mg each g. Bones and Organs 1 –5 grams h. Sperm Cells 3 swabs i. Dried Tissues 100 mg
There are reports indicating that DNA has been isolated from urine samples with nucleated cells, however, it is extremely rare to be able to obtain sufficient DNA to type from urine samples. Other types of biological evidence, such as tears, perspiration, serum and other body fluids without nucleated cells are not amenable to DNA analysis. It should be kept in mind that not all biological materials listed above in case work submitted to a forensic laboratory are in such a state that DNA can successfully extracted and analyzed. When collecting any type of body fluid or tissue, the universal precautions for body fluids should be taken. Wear gloves anytime these specimens are handled and additional protective equipment when appropriate. All body fluids and tissues must be assumed to be infectious regardless of the source (NBI, DNA Section, 2000). The different types of biological evidence listed above can be used to link a person to another individual, to an object, or to a location. These types of evidence could also be used to associate or disassociate to an individual with a crime. Biological evidence is generally transferred by one of two means: direct or secondary (indirect).

Direct deposit Blood, semen, body tissue, bon, hair, urine and saliva can be transferred to an individual’s body or clothing, or to an object or crime scene directly. Once liquid biological specimens have been deposited, they become stains and adhere to the surface. Non-fluid biological evidence, such as tissue, bone or hair, can also be transferred by direct contact and deposited. Direct deposit and transfer could result from any of the following situations:
1. Suspect’s DNA deposited on victim (ex: suspect’s blood or semen deposited on victim’s clothing or body).
2. Suspect’s DNA deposited on an object (ex: suspect’s blood found on a murder weapon). 3. Suspect’s DNA deposited at a location (ex: suspect’s semen found on victim’s bed sheet).
4. Victim’s DNA deposited on suspect (ex: victim’s blood found on suspect’s body or clothing).
5. Victim’s DNA deposited on an object (ex: victim’s blood found on suspect’s watch).
6. Victim’s DNA deposited at a location (ex: victim’s blood found on suspect’s vehicle).
7. Suspect or victim’s DNA deposited on witness (ex: suspect’s blood shed on bystander’s clothing).
8. Witness’ DNA deposited on an object (ex: witness of the crime left his jacket with DNA at the scene).
9. Witness’ DNA deposited at a location (ex: witness of the crime left hairs at victim’s vehicle).

Secondary (indirect Transfer)
Blood, semen, body tissue, hair, saliva, or urine could be transferred to a victim, suspect, object or location through an intermediate medium. In a secondary transfer, there is no direct contact between the original source (donor of the DNA evidence) and the target surface. For example, a rape victim’s clothing bearing seminal stains may rub against a bed sheet in the emergency room or a shooting victim’s clothing bearing a bloodstain may contact an operating room table. Another example of secondary transfer would be a person who picks up a victim’s hair from the suspect’s vehicle seat and deposits it on another vehicle seat. The transfer intermediary cold be a persons, object or a location. A secondary transfer does not necessarily furnish positive proof of a direct link of an individual with a specific crime.

Collection and preservation of biological evidence
The ability to perform successful DNA analysis on biological evidence recovered from a crime scene depends very much on what kinds of specimens were collected and how they were preserved. Thus, the technique used to collect and document such evidence, the quantity and type of evidence that should be packaged, and how the evidence should be preserved, are some of the critical points for a forensic DNA testing program. Unless the evidence is properly documented, collected, packaged and preserved, it will not meet the legal and scientific requirements for admissibility into a court of law. If the DNA evidence is not properly documented prior to collection, its origin can be questioned. If it is improperly packaged, cross contamination might occur. And if the DNA evidence is not properly preserved, decomposition and deterioration may well occur. Any of these effects will seriously affect the outcome of DNA typing.
Guidelines for documentation of DNA evidence
The initial stage of physical evidence examination encompasses activities that take place at a crime scene as well as at the forensic laboratory. Documentation is important from two points of view in forensic science: the legal one, and the scientific one. Nothing should ever be altered until its original condition and positions have been recorded. Several different means of documentation are available. Generally, the use of more than one method are recommended. Every major piece of evidence should be documented.

Evidence at a crime scene
1. Photograph the evidence before it is touched, moved or collected..
2. Note the location and condition of the evidence.
3. Note and sketch relationships of the evidence relative to the crime scene and other objects present.
4. Note and sketch the condition of the biological evidence.

Evidence at the Forensic Laboratory
1. Note the package, label, seal condition and exhibits.
2. Initial the package with unique identification marking, lab case number and date.
3. Check the exhibit no. and compare with the submission request to insure that the correct item is being received.
4. Note, sketch and/or photograph, the contents of the evidence item.
5. Check the item against the submission request to insure that the description of the item is correct.
6. Photograph, sketch and/or note the location and condition of biological evidence prior to any sampling.
7. If any preliminary testing is done, record the nature of the test and the result obtained. Always wear clean gloves to avoid any contamination.

Guidelines for collection, packaging and preservation of evidence Once the biological evidence is transferred through direct or secondary transfer, it will remain on the target surface either by absorption or by adherence. In general, liquid biological evidence will be absorbed, while solid state evidence will adhere. The method of collection depends largely on the state and condition of the biological evidence.

For blood and bloodstains Liquid blood samples from a person
1. Liquid blood from a person should be collected by qualified medical personnel.
2. Two tubes of blood, at least 5 mL each, should be collected in vacuum collection tubes with EDTA as an anticoagulant. If conventional serological analyses and or drug or alcohol analyses are to be conducted, additional tubes of blood should be collected. Generally, the blood sample for conventional serological analyses should contain no preservative and the tube for drug or alcohol testing should contain sodium fluoride.
3. Each tube should be labeled with the date, time, subject’s name, location, collector’s name and case number.
4. Blood sample must be refrigerated (not frozen) and submitted to the forensic laboratory as soon as possible.

Liquid blood specimens at the crime scene
1. Liquid blood should be collected with a clean (preferably sterile) syringe or disposable pipette and transferred to a clean (preferably sterile) test tube.
2. A blood clot can be transferred to a clean test tube with a clean spatula.
3. A clean cotton cloth, gauze, or cotton swabs can be used to soak up liquid blood or a blood clot if other equipment is not available (avoid areas containing only serum). If this method is used and a significant delay will occur getting the specimen to the laboratory, the blood should be air dried out of direct sunlight prior to submission to the laboratory.
4. Label the specimens with case number, item no., date, time, location, and evidence collector’s name.
5. Wet blood samples, if they are collected must be preserved in a suitable anticoagulant (EDTA for DNA analysis) and kept in a refrigerator. These specimens must be submitted to the laboratory as soon as possible.
6.
Wet bloodstains. Garments with wet bloodstains
1. Garments bearing wet bloodstains should be placed on a clean surface or hung up and allowed to air dry out of direct sunlight without any heat source, such as hair dryer.
2. Never collect a wet garment or garment with a wet bloodstain in a sealed, airtight container or plastic bag. This practice causes the specimens to retain moisture, and promotes bacterial growth and sample deterioration.
3. Once the garments and stains are dry, package in a paper container with proper labeling.
4.
Objects with wet bloodstains:
1. Small objects bearing wet bloodstains should be allowed to air dry, then collected as is.
2. An effort should be made to preserve the integrity of any bloodstain patterns during packaging and transportation.
3. Large objects that cannot be removed from a crime scene may have wet bloodstain on them. The wet blood should be transferred onto a clean cotton cloth.
4. Bloodstained cotton cloth must be allowed to air dry before packaging in a paper container.
5. Each object and container must be properly labeled.

Dried bloodstains Dried bloodstains on removable items.
1. Dried bloodstains on weapon, garments and other movable objects should be collected separately and by collecting the entire item.
2. Each item should be placed in its own container and these should be sealed and labeled properly.

Dried bloodstains on solid, nonabsorbent surface of immovable objects.
1. The bloodstain pattern should be photographed, documented and sketched to the extent if necessary.
2. The stains can be scraped off the object onto a clean piece of paper.
3. The paper is then folded and placed in an envelope and sealed properly.
4. Each item must be labeled properly.

Dried bloodstains on large or immovable objects where stains cannot be cut, such as walls, concrete, etc.
1. Document, photograph and sketch the bloodstain patterns if necessary.
2. The bloodstain may be scraped off from the object directly, or eluted onto clean, cotton threads moistened with sterilized saline (or distilled water) by rubbing the threads on the stained area.
3. Blood crust can be scraped directly onto a clean paper folded in packet form. The packet is then placed in an envelope that is sealed, and properly labeled.
4. Always obtain a control by repeating the procedure on an adjacent but unstained area of the surface containing the bloodstain.

Dried bloodstains on carpet, upholstery, wood or other objects that can be cut.
1. The stained area should be documented as previously described.
2. A portion of the item containing the bloodstain can be removed by cutting with a clean sharp instrument.
3. Each cutting should be packaged separately and labeled accordingly.
4. An unstained portion of the item should be collected and packaged as a control.

Dried small blood spatters.
1. Small blood spatters are often difficult to remove from their surfaces. It may be possible to collect them using the tape lift method.
2. After proper documentation, clean fingerprint tape can be used to lift the blood spatter from its surface.
3. Each piece of tape is placed into a larger plastic container. The ends of the tape lift should be taped in place to secure the lift.
4. Suspend the tape with the blood spatter portion in the middle of the container.
5. Seal and label the container appropriately.

Bloodstains on vehicles involved in hit and run cases.
1. The exterior surface of the vehicle should be examined thoroughly for the presence of fabric impressions, imprint evidence, paint transfer, hairs, tissue fibers, blood and other trace evidence. All finding should be properly documented.
2. The under carriage of the vehicle should also be examined for the presence of tissue, hair, blood, fibers and other evidentiary material.
3. Photograph all imprint and impression evidence.
4. Remove all trace evidence and properly package.
5. Bloodstains are preferably removed from pointed surface by chipping with a sharp object such as a chisel or screwdriver while at the same time removing paint samples which can be analyzed and compared to any found on the victim. Stains may also be scraped and placed in a clean paper fold if no paint sample is required.
6. Label and seal the envelope accordingly.

Semen and seminal stains.
1. Document the semen evidence by notes, photography and sketching.
2. Use a clean syringe or disposable pipette to transfer liquid semen to a clean, sterile test tube.
3. Label the tube with the case and item number, date, time, location and name of the collector.
4. Keep the specimen refrigerated and submit to the laboratory as soon as possible.
5. Alternatively, liquid semen can be transferred onto a clean cotton cloth or gauze by absorption.. The cloth is then air dried, packaged, sealed and labeled properly.

Seminal stains on movable objects.
1. Seminal stains on panties, clothing, bed sheets, pillows and other movable objects should be collected as is.
2. If an article has a wet stain on it, the stain must be allowed to air dry thoroughly prior to collection of the article.

3. Each item should be packaged separately in a clean paper container.
4. Each item’ s packaging must be properly sealed and labeled.
5. Packaged items should be refrigerated if possible, and submitted to the laboratory as soon as possible.

Seminal stains on large objects that can be cut.
1. Examples of large objects that can be cut, and that could have seminal stains on them are carpets, bedding, and upholstery.
2. If an article has a wet stain on it, the stain must be allowed to air dry thoroughly prior to collection of the article.
3. Each item should be packaged separately in a clean paper container.
4. Each item’s packaging must be properly sealed and labeled.
5. Packaged items should be refrigerated if possible, and submitted to the laboratory as soon as possible.

Seminal stains on immovable, nonabsorbent surface.
1. Examples of these surfaces are floors, counters and metal surfaces.
2. Document the seminal stain evidence as previously described.
3. Use a clean scalpel to scrape the semen stain onto clean paper, and fold the paper into a druggist fold container.
4. Clean the scalpel in between each use to avoid any contamination.
5. Each druggist fold should be placed into its own appropriate paper container.
6. Each container should be sealed and labeled properly.

Seminal evidence from sexual assault victim.
1. Sexual assault victims are always medically examined in hospitals or a physician’s office.
2. Physical evidence should be collected using established procedures.
3. A standard rape kit must be used to collect vaginal, oral and anal evidence as necessary.
4. Each item should be packaged, sealed and labeled properly.
5. Evidence should be delivered to the laboratory as soon as possible.

Tissue, organ or bone specimens. Fresh tissue organ or bone.
1. Each item or evidence should be described in notes, and documented by photography and sketches.
2. This type of evidence item can be picked up with a clean pair of forceps.
3. Each item should be placed in a clean container without any added fixatives.
4. Each container should be properly sealed and labeled, and stored in a freezer.
5. Evidence should be submitted to the laboratory as soon as possible.

Old tissue, organ or bone.
1. Each item or evidence should be photographed and sketched before collection. The size, shape and pattern, and spatial relationships to the rest of the scene should properly documented.
2. Each item should be picked up with a clean-gloved hand. Evidence still connected should be collected together.
3. Be careful not to contaminate any item with material from another item. Change gloves for every different item.
4. Each item should be placed in a clean container, the container then sealed and properly labeled as previously described.
5. Evidence can be stored at room temperature, and submitted to the laboratory as soon as possible.

Hair evidence for DNA analysis:
1. Hair evidence can be picked up using a clean pair of forceps.
2. Each group of hair evidence items should be packaged separately; the packaged then are sealed and labeled properly.
3. Exercise care in collection so as not to damage present hair root tissue.
4. Hairs mixed with blood, tissue or other body fluids should be treated with care. Each item should be placed in a clean container with appropriate cover then label properly.
5. Evidence should be stored in a refrigerator and submit to a crime laboratory as soon as possible.
6. If hairs are mixed with wet body fluids, these must be dried thoroughly under room temperature prior to submission if a delay occurs.

Things to do in handling and preservation of biological evidence for DNA analysis:
1. Ensure that proper chain of custody is maintained in the handling of physical evidence for examination until court presentation.
2. Recovered pieces of evidence from the crime scene must be properly preserved and documented. They must be properly identified for purposes of court presentation.
3. Have separate containers for different samples.
4. Immediate extraction of DNA samples from biological evidence is a must (done in laboratory therefore submission should be as soon as possible).
5. Place blood or liquid tissues in spill-proof containers.
6. Materials where samples are placed should be sterile.
7. When collecting any type of body fluid or tissue always wear gloves and additional protective device when appropriate.
8. Blood samples must be refrigerated only never place in the freezer..

Things not to do in handling and preservation of biological evidence for DNA analysis.
1. DNA test is very sensitive and vulnerable to contamination by other DNA sources. Avoid contamination with other human DNA.
2. Do not handle samples with bare hands. Always use gloves for protection.
3. Avoid long-term storage of tissues.
4. Ice and dry ice should never be used to cool the tube of blood.
5. Do no pipette any body fluid through mouth regardless of the source.
6. Avoid drying wet stained garments under direct sunlight or exposing it to an electric fan, neither dry this inside an oven.
7. When collecting garments wet with bloodstain never placed it in a sealed air-tight container like plastic cellophane or bag. Never placed inside a plastic bag a collected blood specimen. Put it inside a paper bag or brown envelope.

FORENSIC EVIDENCE MAPPING Forensic Evidence Mapping is a diagram that illustrates series of events connecting all legends found in every crime committed that conceptualize the photographic scene of the evidence providing view of all locations associating a suspect and the crime scene, and a link between the suspect and the victim in a sequential manner and chronological order on how the crime began and ended. Forensic Evidence Mapping is a diagram that illustrates series of events, connecting each evidence from one location to another place showing the association of a suspect/accused and the victim, where the commission of acts took place.
It is an ideal illustration if there is more than one evidence , or more than one victims since it illustrates the location of a victim and evidence at the time the crime was committed. It is very important especially when there is more than one location of crimes committed by one assassin. The location of evidence in every crime scene are indicated connecting either to the victim of the crime or possession of the suspect. Directions are indicated by means of arrow pointing to the direction
Below is a case of series of murders performed by only one person. Read and consider the case of “Joseph Christopher” in 1980. Provide a “Forensic Evidence Map” of the case.

The Case of “JOSEPH CHRISTOPHER”
Date: 1980
Location: Buffalo and New York City, New York
Significance: Serial killers are usually creatures of habit; they find a method of destruction that works and stick to it. However, this extraordinary murderer employed no fewer than different types of weapons to achieve his deadly aims. In the fall of 1980, two separate but equally brutal murder sprees rocked New York State. The first began on September 22, when Glenn Dunn, A fourteen-year-old Afro-American, was shot and killed outside a Buffalo supermarket. The next day, two more black males were gunned down. On September 24, a fourth was shot to death in nearby Niagara Falls. All were killed at close range by an “unidentified white youth” who carried a firearm in paper bag. The bag served two purposes: besides affording concealment for the weapon, it also caught the expended shell casings, a precaution suggesting that these were no mere random acts of violence but carefully planned slayings. However, in the final shooting, the gunman blundered. Unfamiliar with the Niagara falls area, and in his haste to escape a crowd of pursuers, he dropped a shell casing. Cognizant of this slip-which was heavily reported in the Buffalo media-the “. 22 Caliber Killer” switched his means of attack. Two weeks later, on successive nights , two black cabdrivers were murdered and dumped in an isolated wooded area. One was killed by a screwdriver rammed through the back of his skull, a feat requiring unusual strength; the other was battered to death with square-headed hammer. Both were stabbed several times through the sternum, and in a grisly addendum, each had had his heart cut out. It is no easy matter to excise a heart, and yet the procedures had been performed deftly and without undue mutilation. This, combined with the assailant’s rare bravado-very few serial killers will risk hand-to-hand combat with their victims- led investigators to suspect that they were seeking someone with hunting experience. Whoever it was, he appeared suddenly lost his appetite for killing, several weeks passed without incident. And then came an astonishing onslaught.

Bloodbath Four hundred miles away in midtown Manhattan on December 22, within the space of few hours, five blacks and one Hispanic were stabbed by a man who just ran up and attacked them on the street. Four died, the others sustained serious injuries. After the outburst, the “Midtown Slasher”. vanished. At first, no one connected this murder spree with the earlier mayhem. Not until New York medical Examiner Dr. Michael Baden compared photos of the Manhattan casualties- all slim and mustached-with those in Buffalo were the victim’s physical similarities noted. As if to reinforce this belief, the Slasher reemerged in Buffalo, where another wanton knife binge left two more black males dead and several other wounded. But already clues were surfacing. The paper bag had proved inadequate as a receptacle for the shell casings. No fewer than five were recovered from the first wave of killings, and these, together with the fatal bullets, were sent to the FBI laboratory in Washington, D.C., for analysis. They identified five possible weapons that could have fired such ammunition-four handguns and a rifle. In order to single out the murder weapon, they and to study the firing pin imprints. When a gun is discharged, its firing pin strikes the back of the bullet, leaving a distinctive and individual imprint on the casing. By obtaining illustrations of firing pin marks from all five gun makers, FBI experts were able to eliminate three of the weapons immediately. The remaining two, a handgun and a rifle, were both manufactured by the Sturm Ruger gun company in Southport, Connecticut. From company specifications it was clear that the murder weapon had to be a .22 rifle. Because no eyewitness had reported seeing the gunman carrying a rifle-the murder weapon had been hidden in a brown paper bag-this could only mean that the barrel had been sawed off.
GI Arrested With the net tightening, a strange development occurred the following January. A recently enlisted soldier at Fort Benning, Georgia, was arrested on charges of slashing a black GI. After attempting to emasculate himself with a razor blade, the soldier, Joseph Christopher, twenty-five, was committed to a hospital. There he bragged to a nurse about killing numerous blacks in Buffalo and New York. A search of Christopher’s belongings revealed a supply of .22 caliber ammunition, but more pertinent was the discovery that he had joined the army on November 13-which coincided with the lul in killing-and that he had been furloughed since December 19. A bus ticket logged his arrival in Manhattan one day before the killings began. In the buffalo where the Christopher’s lived with his mother and sisters, police searched the basement and there found a single bullet that had misfired; the bullet and shell hadn’t separated. On the casing was the firing-pin imprint, an exact match with the cartridges found at the crime scenes. As anticipated, Christopher was an avid hunter, and at the family’s hunting lodge, forty miles southwest of Buffalo, police uncovered a virtual armory: boxes of .22 caliber ammunition, an extensive gun collection inherited from his father, and the sawed-off barrel of a .22 rifle. The only item missing in an otherwise overwhelming forensic case against the accused was the actual murder weapon. It was never found. In a videotaped confession, Christopher, not known to be a racist, revealed details of the killings that only the murderer could have known. The only motive he ever offered for his outburst was that “something came over me… It was something I had to do.”

Sentenced to life imprisonment, Christopher was never tried for the murder of the two mutilated taxi drivers because prosecutors feared that putting such revelations before a jury might increase the chances of an insanity verdict and the concomitant risk of possible release at a late date.
Conclusion
By any standards, Joseph Christopher has to be considered one of the most remarkable killers of recent times, and his case underline the degree of importance that modern courts attach to solid physical evidence. The two eyewitnesses to the killings, emphatic that Christopher was not the gunman, went largely unheeded, their testimony overwhelmed by the sheer weight of the forensic evidence that prosecutors has amassed.
From the Casebook of FORENSIC DETECTION , Colin Evans