Forensic Analysis Techniques Flashcards

What type of evidence is produced when a suspect's shoe creates an impression in soft soil?

Answer: Three-dimensional impression evidence

A shoe impression in soil is three-dimensional, capturing depth, width, and surface details that can be cast for comparison.

Which controlled substance color test produces a purple/violet reaction when testing for opiates?

Answer: Marquis reagent

The Marquis reagent turns purple/violet in the presence of opiates such as morphine and heroin.

In forensic pathology, what is a 'petechial hemorrhage' and what can it indicate?

Answer: Tiny burst blood vessels in the eyes or skin suggesting asphyxia

Petechiae are pinpoint hemorrhages that occur when capillaries rupture, commonly associated with asphyxia and increased venous pressure.

What does 'chain of custody' documentation primarily ensure in forensic analysis?

Answer: Evidence integrity and admissibility in court

Chain of custody documents every person who handled evidence, ensuring it was not tampered with and is legally admissible.

Which type of fracture pattern on glass can indicate the direction of force application?

Answer: Radial and concentric fracture patterns

Radial fractures extend from the impact point while concentric fractures circle it; their sequence and stress patterns reveal force direction.

In a fire investigation, what is 'V-pattern' burn evidence used to determine?

Answer: The point of fire origin

V-patterns on walls form as fire burns upward and outward from its origin point, helping investigators identify where the fire started.

What forensic technique uses stable isotope ratios to determine geographic origin of materials?

Answer: Isotope ratio mass spectrometry (IRMS)

IRMS measures ratios of stable isotopes (like carbon-13/carbon-12) which vary geographically, linking materials to specific regions.