You have just obtained an item of evidence from the evidence locker. The brown paper package with intact evidence seals appears soggy at one end and there is a strong odor associated with it. On opening the evidence bag you see what appears to be a blood soaked item of clothing that has been wrapped in an unsealed plastic bag while still wet. The item is heavily stained and infested with maggots.
1. Describe the appropriate packaging for this type of item and procedures that should have been conducted back at the lab on receipt of the evidence? [2pts]
2. From a biological standpoint, what effect would the inappropriate packaging described in #1 have on the following tests [3pts].
a). Kastle-Meyer presumptive test
b). Biochemical marker identification
c). Species tests
3. Describe a series of experiments you could conduct to determine whether the Kastle Meyer test is valid under the conditions described in question 2 [8pts].
4. You are asked to examine a vaginal swab from an alleged sexual assault. The presumptive test for semen is positive, but microscopic examination reveals no presence of spermatozoa.
a). Which test would you conduct to confirm whether there is indeed semen present on the swab [1]?
b). Assuming further tests determine the presence of seminal fluid on the swab, explain possible reasons for the absence of spermatozoa [2]
5. In the blood spatter image shown above the blood droplets were traveling from left, upwards to the right. True or False [1pt]
Without calculating, angles of impact, at what angle do you think the blood droplets hit the target surface? [1pt]
A. 90°
B. < 90°
C. > 90°
