CROW’S FEET

SUMMARY OF THE MOVIE

The investigation of four forensic chemists started two days after the homeowner was exterminated inside the tented house. The homeowner Elliot Beckman was found dead in his house.

Sara, Grissom, and Greg from the crime lab investigator or the CSI, investigate the cause of death of the homeowner by entering the house of the victim and suspected that exterminators uses sulfuryl fluoride. A gas used as a structural fumigant insecticide to control dry wood termites. It can also be used to control rodents, powder post beetles, bark beetles, and bedbugs.

Greg continues to investigate the other room obtaining a blue feather. Later, they found out that the feather was matched to a kind of bird called “Hyacinth Macaw”. They have 4 suspects including the two neighbors, namely Rory Kendell and Zach Alfano and the two fumigators, Ted Martin and Nate Allen.

They examine the outside of the tented house by snapping photos of the tent, discovered a trail of sand leading from it and straight to the neighbor’s house. They interviewed Rory Kendell and found out that he haven’t left his place and has been laid up in his house for two days and asked for a urine sample to test if he is affected in the sulfuryl fluoride poisoning.

In the laboratory, they found out that the termite fumigant enters the victim bronchioles causing his lungs to fill with fluid. They also noticed the bruise in the victim’s cheek. One of the chemist revealed that several prints of the clamps in the open window is matched to Zach Alfano. Brass then interviewed this person in the hospital obtaining some information. Alfano tried to help the victim by entering the window but due to suffocation he failed to do so. He ran out of the tented house without Mr Beckmann. According to the results of urine analysis of Rory Kendell, he is positive of sulfuryl fluoride in his body. So they suspected him that he was in there in the actual scene of Elliot’s house. Since he didn’t responded the doorbell when Zach knock on his door. At the laboratory Grissom is trying to make a smoke bomb out of potassium nitrate and white sugar. He and Sara release the white smoke in the Beckman’s house as Greg was in the external Beckman’s front yard to Kendell’s backyard, found out that white smoke coming from Beckmann’s house leaking out under the closet door.

For the following days they search for the owner’s bird inside the house, discovered a dead carcass of rat with fresh maggot colonies in the kitchen, since they didn’t find the bird for the first attempt, Grissom head to the bird to locate the missing hyacinth or if someone sold that bird. He found out that the bird shop has only one blue Hyacinth which was sold to Mr. Beckmann. Then Grissom show the picture of the hyacinths feather and the manager of the shop worriedly said that Macaws only molt one tail feather at a time and get a pile like this, someone yanked real hard.

Grissom test the feathers if there is a finger print left. He used dusting powder (cocoa powder) to trace the finger prints and found out that the print is match to Ted Martin. So they search for the bird in Ted Martin’s residence, found the bird inside the cage in the bathroom.

THE PROBLEM

STRANGE DEATH (Gas Suffocation): WHO’S THE KILLER?

The homeowner Elliot Beckman was found dead in his house. Sara, Grissom, and Greg from the crime lab investigator or the CSI, investigate the cause of death of the homeowner by entering the house of the victim and suspected that exterminators uses sulfuryl fluoride. A gas used as a structural fumigant insecticide to control dry wood termites. It can also be used to control rodents, powder post beetles, bark beetles, and bedbugs.

The investigators looked around for possible samples and to gather information’s. Greg continues to investigate the other room obtaining a blue feather. Later, they found out that the feather was matched to a kind of bird called “Hyacinth Macaw”. Sara and Greg looked the surroundings of the house and found an open window and a trail of sand leading from it and straight to the neighbor’s house named Rory Kendell. For curiousness of the two investigators they interviewed Rory Kendell and asked for urine sample if he is affected with the sulfuryl fluoride poisoning.

In laboratory, Elliot’s organs especially lungs was test if it is positive of sulfuryl fluoride gas. They also noticed the bruise in the victim’s cheek. Brass interview Zach Alfano because his finger prints revealed in the window of the victim’s house.

Grissom go to the bird shop try to ask the manager if he knows the buyer of the hyacinth Macaw bird. Then he shows the feather picture of the bird that was left in the house of Elliot.

The investigators suspected four persons including the two neighbors, namely Rory Kendell and Zach Alfano and the two fumigators, Ted Martin and Nate Allen.

SELECTING A METHOD

The concentration ranges from 250 pounds of sulfuryl fluoride. Following fumigation, no one should enter the area without a self-contained breathing apparatus until measured air concentrations are below 5 ppm.

This problem demanded high quality of accuracy to avoid this tragedy. The analyst found that there are other components in the sample and that was the sulfuryl fluoride. The physical properties of the sample are color, smell (odor), acidity and density; and its chemical properties are glucose, ketones, protein, blood, salts and pH. In this case study there are three samples such as: the lungs of the victim, the urine of Rory Kendell, and the feathers of Hyacinth Macaw bird for DNA finger printing.

In this case study it is more on forensic analysis but analytical chemistry is always involve in this study.

PROCESSING THE SAMPLE: OBTAINING REPRESENTATIVE SAMPLE

In the laboratory, the lungs of the victim were removed for analysis because it can accumulate fluid in the lungs, which can cause to death [1]. Rory’s urine for analysis of Sulfuryl fluoride, SO2F2[2]. And lastly the blue feather of hyacinth macaw [3].

PROCESSING THE SAMPLE: PREPARING A LABORATORY SAMPLE

For this problem, it was not stated that the lungs sample was homogenized or whatever they do but probably the analyst homogenize the sample[1] and since the analyst knew that the victim was positive for SO2F2(gas) they focus on the Kendell’s urine the neighbor of the victim[2]. And then the three feathers of blue hyacinth macaw were collected for finger printing analysis

PROCESSING THE SAMPLE: DEFINING REPLICATE SAMPLE

It is not stated in the problem of how many replicate and volume of each replicate. For urinalysis the prescribe volume they get from the whole sample was only 5mL. Probably for Kendell’s urine the analyst get 5mL to undergo some test. Then, one feather of blue hyacinth macaw.

DOING CHEMISTRY: DISSOLVING THE SAMPLE

A sample of well-mixed urine (usually 10-15 ml) is centrifuged in a test tube at relatively low speed (about 2-3,000 rpm) for 5-10 minutes until a moderately cohesive button is produced at the bottom of the tube. The supernatant is decanted and a volume of 0.2 to 0.5 ml is left inside the tube. The sediment is resuspended in the remaining supernate by flicking the bottom of the tube several times. A drop of resuspended sediment is poured onto a glass slide and cover slipped. And the feather wasn’t dissolve because it is only for finger printing analysis.

ELIMINATING INTERFERENCES

The only interference on the fluoride electrode is from the hydroxyl ion (OH-) with a selectivity coefficient of about 0.1. This is eliminated by ensuring that the pH is kept below 8. The other function of the TISAB buffer, apart from equalizing the ionic strengths, is as a de-complexing agent to release any fluoride ions which may be bound up in complex molecules.

MEASURING THE AMOUNT OF THE ANALYTE

The fluoride concentration in the sample is measured using an ion specific electrode meter. The fluoride meters use a small sample/TISAB volume for fluoride test measurements.

A result of more than 1 ppm (1 mg/L) means there is fluoride overdose. If a person’s daily fluoride intake is low but their urine fluoride is high, this indicates chronic fluoride poisoning. The high urine fluoride level is caused by fluoride being released from bone into the blood.

Since, the analyte was in gaseous state the investigator probably used gas chromatography for detection of sulfuryl fluoride in the sample.

ESTIMATING THE RELIABILTY OF THE DATA

In this analysis, it was confirm that the cause of death of Elliot Beckman was due to the suffocation of sulfuryl fluoride, SO2F2. Based on their results, the crime suspect Ted Martin has a kleptomaniac hobby that led him to intentionally kill Mr. Elliot Beckman with the used of sulfuryl fluoride. Slfuryl fluoride is acutely toxic to humans, although the severity of toxicological effects is dependent on the exposure concentration and exposure duration. Short-term inhalation exposure to high concentrations may cause respiratory irritation followed by pulmonary edema (an accumulation of fluid in the lungs, which can cause death), nausea, abdominal pain, central nervous system depression, and numbness in the extremities. Chronic longer-term inhalation exposure to concentrations significantly above the threshold limit value (TLV) may result in fluorosis (i.e., fluoride binding to the teeth and bones) because sulfuryl fluoride is converted to fluoride ion in the body.

This case study illustrates the importance of analytical chemistry in forensic analysis that used in the determination and identification of the main crime suspect Ted Martin.