Evidence Collection & Preservation Flashcards

What does the term 'spoliation of evidence' mean in the context of fire investigation?

Answer: The intentional or negligent destruction or alteration of evidence that may be needed in litigation

Spoliation refers to destroying or altering evidence that could be relevant to litigation, which can result in legal sanctions against the responsible party.

Which of the following best describes the 'locard exchange principle' as applied to fire investigation?

Answer: Every contact between a person and a scene results in an exchange of trace materials

Locard's principle states that any contact between two objects results in material transfer, meaning perpetrators leave trace evidence and take some away.

A fire investigator needs to collect a flooring sample suspected of containing accelerant residue. How large should the sample generally be?

Answer: A minimum sample of approximately 1 pint volume or about 500 grams of material

NFPA 921 recommends collecting approximately one pint or 500 grams of material to provide the lab with sufficient quantity for analysis.

When documenting evidence with video at a fire scene, what practice is most important?

Answer: Provide a continuous narrated walkthrough to establish spatial context

A narrated video walkthrough establishes spatial relationships and scene context in a way that still photos alone cannot capture.

What information must appear on the evidence label attached to a collected sample container?

Answer: Case number, sample description, location collected, date/time, and collector's name

A complete evidence label must include all identifying details—case number, description, collection location, date, time, and collector—to support chain of custody.

In Oregon arson investigations, who typically has the authority to issue a search warrant for a privately owned fire scene after the emergency phase has ended?

Answer: A magistrate or judge upon showing of probable cause

After the emergency phase, investigators must obtain a warrant from a magistrate or judge, demonstrating probable cause that evidence of a crime will be found.

How should an investigator handle a piece of electrical equipment suspected as the fire's ignition source?

Answer: Photograph it in place, then carefully package it to prevent further damage during transport

Suspected ignition devices must be photographed in place and packaged carefully to preserve their condition for later laboratory examination by a qualified expert.