ABFM Case Analysis & Practical Application 3

Question 1

A body is recovered from a house fire with severe charring. At autopsy, which finding definitively indicates the victim was alive during the fire?

Accepted Answer

Carbon monoxide saturation of 60% in blood

Answer

Elevated carboxyhemoglobin (carbon monoxide saturation) in blood proves the victim was alive and breathing during the fire, as CO accumulates only through respiration.

Question 2

In a sexual assault case, a forensic nurse collects a vaginal swab 72 hours post-assault. Which biological material is most likely to still yield a male DNA profile?

Accepted Answer

Non-motile spermatozoa heads

Answer

Non-motile sperm heads with intact DNA can persist in the vaginal vault for up to 72–96 hours, whereas motility ceases within hours and PSA degrades more rapidly.

Question 3

A forensic expert testifies about blood spatter at a homicide scene. Low-velocity impact spatter measuring 6–10 mm in diameter with circular to slightly elliptical shapes most likely resulted from:

Accepted Answer

Blunt force trauma at walking speed

Answer

Low-velocity impact spatter (6–10 mm diameter, rounded) is characteristic of dripping blood or blunt force trauma at low velocities, not high-velocity gunshot wounds.

Question 4

An inmate is found unconscious in a cell with miosis, bradycardia, excessive salivation, and bronchospasm. Toxicology shows a cholinesterase level of 15% of normal. What is the most likely cause?

Accepted Answer

Organophosphate poisoning from contraband pesticide

Answer

Cholinergic toxidrome with depressed cholinesterase activity is pathognomonic for organophosphate poisoning, which inhibits acetylcholinesterase.

Question 5

A forensic anthropologist is asked to determine age-at-death from skeletal remains of an adult. Which skeletal indicator provides the most reliable estimate for individuals over age 50?

Accepted Answer

Dental root translucency

Answer

Dental root translucency increases predictably with age and provides the most accurate estimates for individuals over 50 when multiple skeletal age markers converge.

(ABFM) American Board of Forensic Medicine Certification Practice Test

(ABFM) American Board of Forensic Medicine Certification Practice Test

ABFM Case Analysis & Practical Application 3