Crime lab science
attached pdf.
Malden,
MA-July 11th, 2017- 1:21 PM
Police Report
A hiker called 911 to report that while hiking, his dog had run off into the woods. The dog started
barking and would not return so the hiker went into the woods to retrieve his dog. As he got near the
dog, he noticed a man lying on the ground. The hiker attempted to resuscitate the man on the ground
but was unable to do so. The police were called and responded. The area was secured around 1:45
PM. The weather conditions were sunny and warm ( the outside air temperature was 85 F and the
relative humidity was 90%), The man was dressed in a long sleeved shirt, dark leather jacket and jeans.
The crime scene investigation unit was called to the scene to collect physical evidence. Evidence
collected included a 30 ounce bag of an unknown white powder that was found 2.5 feet away from the
body. Hair, soil and glass samples were also found. The medical examiner noted that the victim’s body
temperature was 94 oF. (Questions 1-4,6, 7-9 are worth 8 pts each, question 5 is worth 12 points,
question 10 is worth 24 pts)
1. How many grams of the unknown powder were found?
2. How far away in meters was the unknown powder from the victim?
3. What was the temperature of the victim’s body in Celsius?
4. Based on the victim’s body temperature, what would you estimate as the time of death?
5. Soil samples were also taken from the site. Review the article posted under module resources
(Fitzpatrick and Raven, 2012). Please focus on the first and third part of the article.
a. How does Locard’s exchange principle apply to soil evidence?
b. What techniques were used to determine soil particle size and color?
c. What is pH?
d. What is conductivity?
e. Why were the pH and the conductivity of the soil important in this case?
6. Hair samples were found at the site. They are shown below in exemplars a,b,c. Using the
modules resources and any other documents you find, identify the source of each type of hair
(i.e. human, dog, cat, deer, mouse, etc) and list at least 2 morphological features of the hair type
used in making your determination (i.e. medulla , cuticle pattern).
a.
b.
c.
7. What is the importance of the hair evidence provided in the picture below?
8. How do you think this hair was removed by the victim? What type of microscope would show
this level of detail?
9. Glass fragments were found embedded in the victim’s clothing. The glass has a density of 2.62
g/mL and a RI of 1.47. Referring to the tables below, what do you expect was the source of the
glass?
Table 1. Index of Refraction (RI) Ranges for Several Types of Glasses
Glass Index of Refraction
Headlight glass 1.47-1.49
Television glass 1.49-1.51
Window glass 1.51-1.52
Bottles 1.51-1.52
Ophthalmic lenses 1.52-1.53
Table 2: Densities for Several Types of Glasses
Lead-alkali silicate (lead crystal): 2.65 to 3.0 g/mL
Soda-lime silicate (flat glass): 2.41 to 2.63 g/mL
Auto glass (not headlights): 2.53 to 2.75 g/mL
Pyrex: 2.26 to 2.39 g/mL
Borosilicate (car headlights): 2.20 to 2.29 g/mL
Data taken from Saferstein, R., Criminalistics
10. Watch the following TED talk at http://www.youtube.com/watch?v=l0Qd2nxMC2Y and The
Real CSI Forensic Pathology and Death Investigation
Both of these presentations focus on forensic death investigation. Answer the following questions.
Death investigation can be quite complex. One important aspect is the determination of the cause
of death and the manner of death. How do these two differ? Who makes the determination as to
cause of death and manner of death? Use a case in the videos or one you find online and write a
short summary of the case (150-200 words) (for example, Whitney Houston, Anna Nicole Smith,etc)
and give the cause of death and manner of death.