...Trace Evidence at Crime Scene Student’s Name Institutional Affiliation Trace evidence are substances established in very small amounts at the point of crime that can be analyzed and investigated to come up with viable information about the subject under investigation. Such substances may include hair, fiber, glass, glass, metal, paper, paint or botanical sources such as soil, pollen or leaves. Presence of these traces is as a result of the culprits unconsciously coming into contact with the surface (Fish & Braswell, 2011). How long such traces remain at the crime scene depends on the persistence of the substance in terms of its size and shape, amount deposited, actions between deposition and revival, scenery of environment and the amount of time passed. Irregular services tend to collect the evidence more readily than smooth surfaces. Paint can be in term of liquid, fragments, or smears. This usually identified in terms of color, type, texture, layers structure and composition. When paint dries it forms a layer that is thin and hard. It is made up of several constituents that include carriers, pigments, modifiers, extenders and binders. Carriers are the substance that becomes a solid when evaporation takes place usually an organic liquid. Pigment is the substance that gives the paint its color (Fish & Braswell, 2011). It is worth noting that blue and green pigment is usually organic compounds whereas red, yellow and white...
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...Blood Spatter Pattern Analysis Kimberley Kanuch-Brown Everest University Abstract Given that blood spatter analysis is an emergent field, with rapidly occurring developments have significant probative implications for the court system, this project will seek to examine the multi-faceted elements of blood spatter analysis to provide an overview of the field’s different dimensions. Focusing on technical developments, analytical interpretation and court relevance, the project will propose that blood spatter’s analysis as a mainstream element of the CSI toolkit results from the combination of physical sciences and analytical rigor which lies at its core. Beginning with questions of technical and physical science, the project will examine the manner in which blood spatter analysis is increasingly capable of understanding how human usage of different weapons impacts the static nature of a given crime scene. Moving to questions of interpretation, the project will touch upon the manner in which information technology is improving the rigor and caliber of analysis, and thus leading to greater continuity and replicability in blood spatter analysis. Concluding, it will examine the manner in which the court system is now viewing blood spatter analysis with greater heft because of these developments. Blood Spatter Analysis and Science Beginning with questions of science, the work of Randall (2009) demonstrates how even the most esoteric of weapons can be analyzed using blood-spatter...
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...Running Head: Blood Splatter Analysis Blood Spatter Analysis Kenisha Callahan AJS 592 Dr. Steven Gilbert Blood Spatter Analysis Blood spatter analysis is “the systematic assessment of the visual patterns of bloodstains at crime scenes based on the physics of fluids” (Brodbeck, 2012, p. 51). It has been studied since 1895 when Dr. Eduard Piotrowski published "Concerning the Origin, Shape, Direction and Distribution of the Bloodstains Following Head Wounds Caused by Blows." The next acknowledgment of BPA was in 1955 when Dr. Paul Kirk entered blood splatter evidence in the State of Ohio v. Samuel Sheppard case. Dr. Herbert MacDonell started training personnel of law enforcement about blood spatter analysis in 1971. Since that time, bloodstain pattern analysis has grown and continues to develop. Blood pattern analysis is used in a lot of crime scene investigations and can hold valuable information. Blood spatters can indicate important clues such as, the number of blows to the victim, the force of the blows, weapon used, and position and/or movement of the victim and suspect. Blood spatter can be classified into three categories, low velocity, medium velocity, and high velocity (Saferstein, 2011). Low velocity spatter consists of large separate or compound drops with diameters measuring three millimeters or more. It is usually the result of dripping blood. Medium...
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...Blood is a very good source of evidence. The DNA can be extracted from the blood and help narrow down suspects. The way the blood spatters are found in the crime scene can help investigators piece together the events of the crime. This is why it is important to correctly document and handle it while avoiding cross contamination. Forensic scientists are faced with either dried blood or wet blood. Different methods of extracting the blood sample sometimes depends !3 on the location of it. Each hold their advantages and disadvantages in their approaches to retrieve the best quality of samples. Biological Evidence Pertaining to dried blood stains, different methods are required to retrieve a good sample. One method is “tape lifting” bloodstains by...
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...Crime scene investigation is the meeting point between science, logic and law. Processing a crime scene is and long and tedious process and is the job of crime scene investigators (CSI). CSI has the responsibilities of collecting, documenting, preserving, reconstructing and presenting evidence. It is their job to examine any physical evidence that could remotely shed any light on what happened and who is responsible. There are no typical crime scenes, evidence or investigative approaches and every crime scene should be approached in a systematic sense. According to Robert R. Ogle Jr., a crime scene search is defined as a systematic, methodical search for any physical evidence at a crime scene. Before the job of CSI can begin, there has to be a crime committed. For instance, CSI are on call for murder scene investigations to collect and examine evidence. When CSI is contacted, their job begins. Evidence is a major part in any investigation. Without evidence, a case can grow cold quick. Anything can be evidence and when in a crime scene, everything should be treated as such. Evidence has many different categories: trace, firearm, impression, drug and alcohol, document, and biological fluids. All of these categories of evidence play an important part in finding out valuable information towards solving a case. The most important aspect of evidence collection and preservation is protecting the crime scene. When first approaching a crime scene, first responders should secure the...
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...Blood Stain Pattern Analysis: Blood stain pattern analysis is a form of forensic science that examines blood at crime scenes. From analyzing blood at the crime scene analysts can determine many different things about the crime scene. Some of which include: Where the blood came from What caused the wounds? From what direction was the victim wounded? How were the victim(s) and perpetrator(s) positioned? What movements were made after the bloodshed? How many potential perpetrators were present? Does the bloodstain evidence support or refute witness statements? Because blood behaves according to certain scientific principles, trained bloodstain pattern analysts can examine the blood evidence left behind and draw conclusions as to how the blood may have been shed. From what may appear to be a random distribution of bloodstains at a crime scene, analysts can categorize the stains by gathering information from spatter patterns, transfers, voids and other marks that assist investigators in recreating the sequence of events that occurred after bloodshed. This form of physical evidence requires the analyst to recognize and interpret patterns to determine how those patterns were created. Analysts must obtain a four year degree in forensic science or a Bachelor of Science degree before becoming an analyst. Often elastic string is stretched from blood droplets on the angle that of impact to determine where the blood originated from. Blood splatter can tell the police...
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...Bloodstain Pattern Analysis Bloodstain Pattern Analysis (BPA) is the examination of the shapes, locations, and distribution of patterns of bloodstains, in order to provide an interpretation of the physical events that gave rise to their origin. When BPA is done properly, many things can be discerned including distance from the blood source to the target, direction of travel and impact angles, nature of the force used to cause the bloodshed, sequencing of multiple bloodshed events, and interpretation of contact or transfer patterns. When it has been properly documented, BPA can also be used to confirm of refute the position of a victim, witness, suspect, or defendant, determine if there is evidence of a struggle, or if the assault was “one sided”, and confirm or refute statements made by the principles in a case, as in telling if the patterns match accounts given by victims, witnesses or defendants. Blood has specific characteristics that are exhibited in the way it behaves when separated from the blood source. Blood is always spherical in shape until it impacts a particular surface. This is due to the fact that blood naturally pulls in on itself, both horizontally and vertically, due to its specific surface tension. Spatters of blood occur when blood is acted upon by force and travels through the air before landing on a target surface. Transfers occur when a blood source comes in direct contact with the target surface area. Depending on the surface texture of the area, bloodstains...
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...14 December 2014 Blood and Guns The world of Forensic Scientist is an amazing and fascinating place. There are so many aspects that go into forensic science but in this paper we are only covering bloodstain spatter patterns. Bloodstain spatter patterns are not solely used to solve crimes but I do feel it is one of the most important. Bloodstains never lie. A bullet is traveling at its fastest speed when it leaves the barrel of the gun. Bullets traveling after firing is said to be using kinetic energy. Kinetic energy is the energy the bullet has due to its motion from the firing pin striking the gun powder causing an explosion that forced the bullet to discharge from the barrel. Now this bullet possess kinetic energy and will do harm to anything lying within its targeted path. (Kinetic Energy website) The kinetic energy given to bullets fried from rifles will be a higher velocity then that of a pistol or shot gun. Rifles barrels are longer and constructed to with stand more pressure and thus leading to a greater velocity of kinetic energy on a bullet (Warlow 67). Death can occur from firing a bullet straight up in the air. When the bullet is returning to the earth due to the gravitational pull it will pick up velocity. However the bullet can return either base or head side up (89). Powders also have different burning rates for different guns. When you have a longer barrel your burning rate of powder will be longer but if your barrel is shorter then you will have a faster...
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... 3.1.1 Blood Detectives - Conclusion Questions You fall down and scrape your hand – describe what each component of blood would be doing at the injury site. At the injury site, each component of blood would be doing various jobs. For example, both the plasma and the platelets would assist to clot the blood, thus a person would not bleed out. Furthermore, the white blood cells would aid in prevention of injection. In addition, the red blood cells would help to deliver oxygen to the injury site. Anna has a condition called sickle cell anemia, a blood disorder. Based on the differences you observed between the normal blood slide and Anna’s blood slide, what do you think is a defining feature of this disease? Explain your answer. A defining feature of this disease would be the sickle-shaped cells that can clearly be seen under the microscope, compared to normal blood cells, which are round. Also, there is more plasma in Anna Garcia’s blood sample as a result of the reduced amount of red blood cells. How does the abnormal shape of a sickled red blood cell affect its movement through blood vessels? The abnormal shape of a sickled red blood cell affects it movement through blood vessels because, the sickled red blood cells appear like a crescent moon, which do not move easily through the blood vessels, causing the red blood cells to become stuck and then accumulate in the blood stream. This causes clotting, as well as pain and other complications. People with sickle cell anemia often...
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...Natasha Warburton Homicide Week 7 Bloodstain pattern analysis is defined as the examination of shapes, locations and distribution patterns of bloodstains, this source has been a helpful resource to the law enforcement with solving there case and recognizing what type of criminal act was committed. Bloodstain patterns can help investigators understand the actions and motions of the victim and the suspect throughout the crime scene. The patterns may indicate that a crime first thought of as a suicide was in fact a homicide. The analysis of bloodstain patterns is a complicated discipline and requires much experience with many different situations to learn to do an accurate reading. The bloodstain pattern analysis plays a very important role in the reconstruction of many crime scenes. The various types of bloodstains account for how the blood was projected from the body. Blood may be dripped out of the body, sprayed from an artery, oozed out through a large wound or flung off a weapon that has struck another person. Through bloodstain pattern analysis, analysts can determine, among other things, the type of injuries received, the order in which the injuries were received, whose blood is present at the scene, and more. As I read throughout the chapter I notice that bloodstain pattern analysis can form a very interesting story that keeps the media itself entertained. The reason I said this is that, it turns out that the location where the blood lands, and the shape of the...
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...also interesting that if the forensic officers had not gone through every single hair fiber on the brush they had found, they could not have had enough evidence to convict the killer. Science and Methods Used In this case there were many different scientific methods such as an ultraviolet light test, a luminol test, an amido black test, and the use of a highly trained dog. Two main scientific methods used in the solving of this case were hair and DNA analysis and the use of mass spectrometry. When the woman was missing and the only lead the forensic officers had was the bloody pillow case; they had to use various scientific methods in order to solve the case. The forensic officers started using their methods where they suspected the crime had taken place which was in the woman’s bedroom. They noticed that woman’s bed was clean and had no blood on it. They suspected that the blood might have been cleaned up and decided to use luminol. “Luminol is the most sensitive test that is capable of presumptively detecting bloodstains diluted to as little as 1 in 100,000;...
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...Bloodstain pattern analysis are as the examination of shapes, locations and distribution patterns of bloodstains, in order to provide an interpretation of the physical events Bloodstain patterns can help investigators understand the actions and motions of the victim and the suspect throughout the crime scene. The patterns may indicate that a crime first thought of as a suicide was in fact a homicide. The analysis of bloodstain patterns is a complicated discipline and requires much experience with many different situations to learn to do an accurate reading. The bloodstain pattern analysis plays a very important role in the reconstruction of many crime scenes. The various types of bloodstains account for how the blood was projected from the body. Blood may be dripped out of the body, sprayed from an artery, oozed out through a large wound or flung off a weapon that has struck another person. Through bloodstain pattern analysis, analysts can determine, among other things, the type of injuries received, the order in which the injuries were received, whose blood is present at the scene, the types of weapons used in the crime, whether or not the victim was in motion at the time the injury was inflicted, and how far the blood droplets fell before hitting the surface upon which they were found. The shape of drops of blood can reveal all sorts of significant information. Some experienced analysts are even able to use some of the bloodstains to recreate the event. Three main...
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...Mathematics has even paved its way into music with each beat of music being timed by numbers. Math is everywhere and people with brilliant minds can use mathematics to contribute to the world in very positive ways. One such way is the science of forensics. Without math, forensics could not exist. As population growth increases at an alarming rate, people have to find ways of holding people accountable for unlawful behavior. Forensic science has allowed civilization to evolve and become less barbaric and move towards factual based evidence when solving crimes against nature. Forensic science measures facts involving a crime and figure out the truth behind those measurements. Whether it is the skid marks from a vehicle collision or blood splatter analysis; mathematics is the reason why this can be done. Forensics have paved the way to a better justice system providing factual based evidence based upon math laws that are accepted as truth. The study of ballistics and the trajectory of bullets is a crucial element in crime solving strategy. In the United States, it is everyone’s privilege to own a gun lawfully. If the majority of the people had guns, it would be important to have a way of holding citizens accountable. This is done with mathematics....
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...Forensics of Blood Blood evidence is the most common, most recognized and possibly most important evidence in the world of criminal justice. Throughout the history of violent and fatal crimes, bloodstain evidence has recently begun to emerge as a recognized forensic skill. “Blood is one of the most significant and frequently encountered types of physical evidence associated with forensic investigation of death and violent crime” (Eckert & James, 11). When a violent crime has been committed, blood is commonly left behind at the scene of the crime. This blood evidence allows police investigators to piece together the events of the crime. The texture, size, shape, and distribution of the blood can be used to determine when the crime occurred, what weapon was used, how the victim was standing, how many times the victim was hit, and more. Even if the perpetrator attempted to cover up the crime by cleaning the blood, evidence of blood still remains. Forensic investigators have different tests that can see where blood has been, whether it is blood, saliva, or semen, and also can test whether the blood is even human or not. Going even further, more tests can be done to compare the blood of different individuals to determine whether or not they were the perpetrator. Within the blood, there is a liquid portion called plasma making up about 55% of the total volume of blood. The plasma contains mostly water with some nutrients, minerals, and oxygen. In the plasma, there are red and...
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...Forensic Chemist The trunk of a stolen car smells of decomposed flesh, a pair of Converse high tops with tiny specs of blood spatter are all alone in the back seat of the same car, and a half smoked cigarette rests softly on a freshly mowed lawn next to the driveway. These are clues of a crime scene. Each clue adds up to the story of something terrible. A crime has taken place, and law enforcement is on the scene. Whether it is a detective, county Sheriff or the FBI, the investigators will rely on their forensic teams to link all the pieces of the puzzle that don’t quite fit yet. A Forensic Chemist can make them fit by scientifically analyzing the evidence. Chemistry, biology, materials science, and genetics to analyze clue found at the scene of the crime, on the victims or in the bodies of the bad guys. Forensic Chemists go into a case with many unknow pieces of the crime scene they need to analyze to determine the nature of each sample. Most Forensic Chemists work in a lab. It is rare for private labs to do this kind of work so most of the time these labs are associated with Local, State, or Federal law enforcement agencies. From local Medical Examiner’s labs to state of the art FBI labs, Forensics Chemists often provide the strongest evidence in court against the defendants. They have many different types of test and methods they use to figure out what the samples mean. Each crime scene brings new types of clues and samples so a Forensic Chemist must always...
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