Crime lab science
Case Scenario Part IV
Sudbury, MA State Police Crime Laboratory
July 20, 2017
The body found at the Malden location has been taken to the State Medical Examiner’s Office for an
autopsy and processing. It appears that the victim has been shot although the cause of death has
not yet been determined. Meanwhile, police have found the victim’s home burned to the ground
and suspect that arson might have occurred.
Please answer the following questions with regard to the victim (questions 1-15 are 5 pts each,
question 16 is 25 pts) .
- The medical examiner performs a visual examination of the body and finds a bullet entrance
wound. There appears to be a ring of deposited smoke and lead as a halo around the bullet
hole. What would be the approximate distance from which the bullet was shot?
- The medical examiner swabs an area near the entrance wound. She is trying to determine if
there is GSR near the wound. List three elements that might be present in GSR. What are the
chemical symbols for these elements? How many protons, neutrons, and electrons do they
- The medical examiner sends the swab to the inorganic analysis laboratory section. What
analytical technique might they use to simultaneously determine the three elements found in
- The medical examiner has found an unknown metal object in the victim’s pocket. She requests
that the inorganic analysis laboratory section perform a non-destructive test on the metal to
determine the elemental composition. Which analytical technique might the lab choose?
- The metal in the victim’s pocket appears to have been melted and has a pink color. What
temperature do you expect the metal has been exposed to?
Arson investigators have gone to the scene of the victim’s house.
- A witness at the scene states that she saw smoke coming out of the window and called the fire
department. The fire department was there within 5 minutes and the house was completely
engulfed. Based on the fact that fire is a chemical reaction, why do you think the fire spread so
- While the victim’s house has burnt down, the garage is intact. There are several cans of
kerosene there. Based on the flash point, how do you think this would compare to gasoline for
use as an accelerant? Which has the higher flashpoint?
- Based on the composition of gasoline and kerosene, why would gasoline be easier to ignite?
- What is the difference between the flash point and the ignition temperature?
- The house had a wooden frame. List two burn patterns that could be used to make a
determination as to the origin of the fire.
- Residue is found that needs to be taken back to the lab for analysis. How should the evidence
- Prior to testing, the sample undergoes solid-phase micro extraction. Why is this technique
needed prior to testing?
- What is the purpose of the carrier gas in chromatography?
- What order do the components of the sample leave the chromatograph?
- Results of the gas chromatograph indicate that a combination of accelerants may have been
used. What technique might assist in determining the accelerants used?
- Research the assassination of John F. Kennedy https://www.youtube.com/watch?v=W-l23ec-
Write a 150-200 word summary focusing on one aspect of forensic analysis that was not available
when the assassination occurred 50 years ago (use at least two outside sources in your summary).
Consider at least one of the questions below in your response.
What are your thoughts regarding the case? Was there one shooter or multiple shooters? Was
there a “magic bullet”? What are your thoughts regarding the many conspiracy theories surrounding
the case (see http://www.cnn.com/2013/11/16/us/jfk-assassination-conspiracy-theories-debunked/
) for a short video and a list of the most popular conspiracy theories.
Use at least two outside sources in your response and cite using APA format.
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