Certification Examination Practice

Illinois Crime Scene Investigator Certification Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

Question 1: What is the first step a crime scene investigator should take

upon arriving at a crime scene?

• Collect physical evidence
• Interview witnesses
• Secure and isolate the scene
• Take photographs

Answer: C. Secure and isolate the scene

Rationale: Securing the scene prevents contamination and ensures safety

for all personnel involved in evidence collection. 1 / 4

Question 2: Chain of custody documentation is critical because it:

• Helps identify the suspect
• Ensures evidence integrity
• Determines the crime scene perimeter
• Establishes probable cause

Answer: B. Ensures evidence integrity

Rationale: Proper documentation of chain of custody maintains legal

admissibility of evidence.

Question 3: Which type of evidence is most susceptible to contamination if

not handled properly?

• Glass fragments
• Biological evidence
• Firearms
• Soil samples

Answer: B. Biological evidence

Rationale: Biological samples such as blood, saliva, and hair can degrade

or be contaminated, affecting DNA analysis.Question 4: Latent fingerprints are best visualized using:

• X-ray imaging
• Powder or chemical development
• Blood reagents
• Laser scanning 2 / 4

Answer: B. Powder or chemical development

Rationale: Latent prints are often invisible and require powders or

chemicals to make them visible for analysis.

Question 5: What is the primary purpose of photographing a crime scene

before evidence collection?

• To create a courtroom slideshow
• To identify witnesses
• To preserve a visual record of the scene
• To determine suspect involvement

Answer: C. To preserve a visual record of the scene

Rationale: Photographs provide a permanent, objective record of the crime

scene and evidence placement.

Question 6: Which of the following is considered transient evidence?

• Hair fiber
• Fingerprint
• Odor
• Tool mark

Answer: C. Odor

Rationale: Transient evidence is temporary and may be lost if not

documented immediately.Question 7: The use of a grid or quadrant system at a scene is primarily for:

• Evidence analysis in the lab 3 / 4

• Systematic searching and documentation
• Sketching the scene
• Interviewing witnesses

Answer: B. Systematic searching and documentation

Rationale: Dividing a scene into sections ensures a thorough and organized

search.

Question 8: Which of the following best describes class evidence?

• Unique to an individual source
• Associated with a group rather than a single source
• Always visible
• Cannot be used in court

Answer: B. Associated with a group rather than a single source

Rationale: Class evidence narrows the possible source to a group, such as

fiber type or shoe tread pattern.

Question 9: In the collection of blood evidence, which of the following is

correct?

• Always use plastic containers
• Freeze immediately without packaging
• Use paper containers to allow drying and prevent mold
• Submerge in alcohol
• / 4