ABFM Injury Documentation and Evidence Handling 3 — Questions and Answers
Question 1: Which wound characteristic most reliably distinguishes an entrance gunshot wound from an exit wound in intermediate-range fire?
- Larger diameter of the exit wound
- Abraded collar (abrasion ring) at the entrance (Correct answer)
- Irregular lacerated margins at the entrance
- Beveling direction of the skull defect
Correct answer: Abraded collar (abrasion ring) at the entrance
The abraded collar forms as the bullet's spinning motion scrapes the skin margin at entrance, a feature absent at exit wounds.
Question 2: A forensic examiner notes parallel linear lacerations on a victim's wrists. The MOST accurate forensic description is:
- Hesitation marks suggesting self-inflicted injury (Correct answer)
- Defense wounds from fending off an attacker
- Railroad track injuries from a two-edged weapon
- Ligature marks from restraint
Correct answer: Hesitation marks suggesting self-inflicted injury
Multiple parallel, shallow, linear cuts on wrists are classic hesitation marks associated with self-inflicted sharp force injury.
Question 3: Which body fluid stain fluoresces most reliably under alternate light source (ALS) examination at 415–450 nm?
- Whole blood
- Saliva
- Semen (Correct answer)
- Urine
Correct answer: Semen
Semen contains flavin compounds that produce strong fluorescence under ALS wavelengths around 415–450 nm, aiding detection on varied surfaces.
Question 4: A scale reference marker must be included in forensic wound photographs to:
- Indicate north orientation on the body diagram
- Allow accurate size determination in court exhibits (Correct answer)
- Mark the wound as photographed by a certified examiner
- Signal that no flash was used in the image
Correct answer: Allow accurate size determination in court exhibits
A scale (ruler) in the image allows courts and experts to determine true wound dimensions, which is essential for injury comparison and documentation.
Question 5: Petechial hemorrhages in the conjunctivae and skin are classically associated with which mechanism of injury?
- Blunt impact to the occiput
- Asphyxia causing increased venous pressure (Correct answer)
- Thermal burns above 60°C
- High-velocity projectile trauma
Correct answer: Asphyxia causing increased venous pressure
Asphyxia raises venous pressure in the head and neck, rupturing small capillaries and producing petechiae in the conjunctivae, face, and skin.
Question 6: When transferring biological evidence between agencies, the MINIMUM information required on the evidence transfer form includes:
- Case number, item description, transferor signature, date/time, and recipient signature (Correct answer)
- Victim's Social Security number, case number, and agency seal
- Lab accreditation number and examiner's home address
- Photograph log numbers and billing codes only
Correct answer: Case number, item description, transferor signature, date/time, and recipient signature
A complete chain of custody transfer requires case identifier, item description, and documented signatures with dates/times from both transferring and receiving parties.
Question 7: An abrasion pattern showing parallel linear marks in a single direction is most consistent with:
- Blunt rotational force applied in multiple directions
- Unidirectional scraping (brush abrasion) across a rough surface (Correct answer)
- Impact from a blunt cylindrical object
- Ligature under perpendicular tension
Correct answer: Unidirectional scraping (brush abrasion) across a rough surface
Parallel linear abrasions result from skin dragging over a rough surface in one direction, classically seen in falls or drags on pavement.
ABFM Injury Documentation and Evidence Handling 3
Which wound characteristic most reliably distinguishes an entrance gunshot wound from an exit wound in intermediate-range fire?