Criminal Investigations Flashcards

What is the primary purpose of maintaining 'chain of custody' for evidence?

Answer: To document who had possession of evidence at all times

Chain of custody creates a documented record of every person who handled evidence, ensuring its integrity and admissibility in court.

Which crime scene search pattern is most thorough for covering a large outdoor area?

Answer: Grid method

The grid method covers the area twice from perpendicular angles, making it the most thorough search pattern for large outdoor crime scenes.

The Locard Exchange Principle states that:

Answer: Every contact between a criminal and a crime scene leaves a trace

Locard's Exchange Principle holds that any physical contact results in an exchange of material, forming the scientific basis for forensic evidence collection.

When should crime scene photographs first be taken?

Answer: Before anything at the scene is moved or disturbed

Photographs must be taken before evidence is touched or moved to document the original, unaltered state of the crime scene.

In criminal law, 'corpus delicti' refers to:

Answer: The body of facts proving that a crime was committed

Corpus delicti refers to the essential facts and circumstances proving that a crime actually occurred, independent of any confession.

Which type of fingerprint is invisible to the naked eye and requires development techniques to be detected?

Answer: Latent fingerprint

Latent fingerprints are invisible impressions left by skin oils that must be developed using powder, chemicals, or alternate light sources.

What is the primary purpose of an investigator's initial walk-through of a crime scene before collecting evidence?

Answer: To gain an overview and develop the investigation plan

The initial walk-through allows investigators to assess overall scene conditions and develop a systematic plan before evidence collection begins.