Crime Scene Investigation Procedures Flashcards

What is the first priority for a CFL arriving at a crime scene involving a lock or door?

Answer: Documenting the scene before touching any evidence

Documentation through photography, notes, and measurements must occur before any physical interaction with evidence to preserve the scene's evidentiary integrity.

Why should a CFL avoid using WD-40 or lubricants on a suspect lock cylinder at a crime scene?

Answer: Lubricants can obscure or destroy trace evidence such as metal fragments, pick marks, and debris

Lubricants can flush away or contaminate microscopic trace evidence including metal transfer marks, tool fragments, and debris critical to forensic analysis.

What information should be recorded in a CFL's scene notes before removing a lock for laboratory examination?

Answer: Location, orientation, door type, lock brand and model, and photographic reference numbers

Comprehensive documentation including location, orientation, hardware details, and photo references ensures the lock's full context is preserved for later forensic interpretation.

When photographing a lock at a crime scene, which lighting technique best reveals pick marks and tool marks?

Answer: Oblique (raking) lighting from a low angle to the lock surface

Oblique or raking light from a low angle creates shadows in surface irregularities, dramatically enhancing the visibility of fine tool marks and surface disturbances.

What is the correct method for packaging a lock removed from a crime scene for laboratory transport?

Answer: Rigid container with padding, properly labeled with case number and chain of custody documentation

Locks must be secured in rigid padded containers to prevent additional damage during transport and preserve existing marks, with complete chain of custody documentation.

A CFL is called to examine a door with no signs of forced entry but reports of unauthorized access. What should be the first examination step?

Answer: Examine the lock cylinder face and keyway under magnification for pick, bump, or bypass tool marks

Magnified examination of the cylinder face and keyway for tool marks is the first step to determine whether covert entry techniques were employed.