CFL Crime Scene Investigation Procedures 1 — Questions and Answers
Question 1: What is the first priority for a CFL arriving at a crime scene involving a lock or door?
- Documenting the scene before touching any evidence (Correct answer)
- Immediately picking the lock to assess its operational condition
- Removing the lock for transport to a laboratory
- Interviewing the property owner about missing or duplicated keys
Correct 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.
Question 2: Why should a CFL avoid using WD-40 or lubricants on a suspect lock cylinder at a crime scene?
- Lubricants can obscure or destroy trace evidence such as metal fragments, pick marks, and debris (Correct answer)
- WD-40 will cause the cylinder plug to seize permanently inside the housing
- Using lubricants violates ALOA professional standards for forensic examiners
- Lubricants create a fire hazard when used in indoor crime scene environments
Correct 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.
Question 3: What information should be recorded in a CFL's scene notes before removing a lock for laboratory examination?
- Location, orientation, door type, lock brand and model, and photographic reference numbers (Correct answer)
- Only the property owner's name and insurance policy number
- The suspected perpetrator's identity and motive if already known
- The responding police officer's badge number and arrival time only
Correct 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.
Question 4: When photographing a lock at a crime scene, which lighting technique best reveals pick marks and tool marks?
- Oblique (raking) lighting from a low angle to the lock surface (Correct answer)
- Direct overhead flash for maximum uniform brightness
- Natural diffuse sunlight through nearby windows
- Ultraviolet light used exclusively without visible spectrum illumination
Correct 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.
Question 5: What is the correct method for packaging a lock removed from a crime scene for laboratory transport?
- Rigid container with padding, properly labeled with case number and chain of custody documentation (Correct answer)
- Standard plastic zip-lock bag with the collecting officer's initials written on the outside
- Wrapped in newspaper and loosely placed inside a cardboard box
- Taped directly to the evidence submission form for compact transport
Correct 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.
Question 6: 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?
- Examine the lock cylinder face and keyway under magnification for pick, bump, or bypass tool marks (Correct answer)
- Assume the property owner provided a key to the suspect and close the investigation
- Immediately disassemble the lock to check and measure individual pin heights
- Contact the lock manufacturer to inquire whether any keys have been reported stolen
Correct 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.
CFL Crime Scene Investigation Procedures 1
What is the first priority for a CFL arriving at a crime scene involving a lock or door?