Criminal Investigation Fundamentals Flashcards

An investigator arrives first at a homicide scene. What is the immediate priority before evidence collection begins?

Answer: Ensure scene safety and render aid to any victims

Officer and victim safety, including rendering medical aid, always takes priority over evidence preservation.

The 'chain of custody' for physical evidence is primarily intended to establish what?

Answer: Continuous, documented control proving the evidence was not altered

Chain of custody documents every person who handled evidence to prove its integrity and prevent tampering claims.

What is the term for the principle that 'every contact leaves a trace'?

Answer: Locard's exchange principle

Locard's exchange principle holds that a perpetrator always brings something to and takes something from a crime scene.

When documenting a crime scene with photographs, why are overall, mid-range, and close-up shots all taken?

Answer: To show context, relationships, and detail of evidence

The three-tier approach captures spatial context, item relationships, and fine evidentiary detail.

A modus operandi (MO) differs from a signature in that the MO:

Answer: Is the method the offender uses to commit the crime and can evolve

An MO is the functional method of committing a crime and may change as an offender gains experience, while a signature reflects a psychological need.

Which search pattern is most appropriate for a large outdoor crime scene with multiple searchers?

Answer: Grid (double-line) pattern

The grid pattern overlaps two line searches at right angles, providing thorough coverage of large open areas.

What distinguishes a 'primary' crime scene from a 'secondary' one?

Answer: Primary is where the main criminal act occurred; secondary is a related but separate location

The primary scene is where the core offense took place; secondary scenes are connected locations such as where a body was dumped.