MCOLES Crime Scene Investigation 4 — Questions and Answers
Question 1: A witness contaminates a crime scene by moving a weapon before officers arrive. What should the first officer on scene do?
- Disregard the moved weapon since it is now contaminated
- Document the witness's account of the original position and note the change in reports (Correct answer)
- Exclude the weapon from evidence entirely
- Ask the witness to move it back to the original position
Correct answer: Document the witness's account of the original position and note the change in reports
Officers must document the original reported location through the witness's account and note the alteration in official reports to preserve investigative accuracy.
Question 2: What is the significance of rigor mortis in a crime scene investigation involving a death?
- It confirms the cause of death definitively
- It helps estimate the postmortem interval or time since death (Correct answer)
- It indicates whether the death was homicide or accidental
- It establishes the exact location where death occurred
Correct answer: It helps estimate the postmortem interval or time since death
Rigor mortis follows a predictable onset and resolution timeline that investigators and medical examiners use to estimate time of death.
Question 3: During a sexual assault investigation, which agency typically takes primary custody of the sexual assault evidence kit?
- The first responding officer
- The crime laboratory (Correct answer)
- The hospital that collected the samples
- The detective assigned to the case
Correct answer: The crime laboratory
Sexual assault evidence kits are submitted to the crime laboratory to maintain a controlled chain of custody and ensure proper analysis.
Question 4: What is 'luminol' used for in crime scene investigations?
- Enhancing latent fingerprints on metal surfaces
- Detecting traces of blood that have been cleaned or diluted (Correct answer)
- Identifying drug residue on surfaces
- Preserving footwear impressions in soft soil
Correct answer: Detecting traces of blood that have been cleaned or diluted
Luminol reacts with the iron in hemoglobin to produce chemiluminescence, revealing bloodstains even after cleaning attempts.
Question 5: An investigator finds shoe prints in mud near a burglary scene. What is the proper collection method?
- Photograph and then lift the print with tape
- Photograph and then cast the print with dental stone or plaster (Correct answer)
- Cover the print with plastic until the lab arrives
- Measure and sketch only; do not disturb the mud
Correct answer: Photograph and then cast the print with dental stone or plaster
Three-dimensional impressions in soft media like mud must be photographed and then cast with dental stone or casting plaster to capture depth and detail.
Question 6: Under Michigan law and MCOLES standards, who has ultimate authority over a crime scene?
- The county medical examiner
- The lead detective or officer in charge of the investigation (Correct answer)
- The fire department if there is fire involvement
- The first patrol officer on scene until relieved
Correct answer: The lead detective or officer in charge of the investigation
The lead investigator or officer in charge of the investigation holds authority over the crime scene, including access and processing decisions.
Question 7: A bloodstain shows a circular shape with smooth edges and no satellite spatter. What does this indicate about the drop's direction of travel?
- The blood was propelled at a high velocity
- The blood fell from directly above, at a 90-degree angle (Correct answer)
- The blood was cast off from a moving weapon
- The blood was transferred by direct contact
Correct answer: The blood fell from directly above, at a 90-degree angle
A circular bloodstain with smooth edges and no satellite spatter indicates a perpendicular (90-degree) drop from directly above, resulting in minimal distortion.
MCOLES Crime Scene Investigation 4
A witness contaminates a crime scene by moving a weapon before officers arrive.
What should the first officer on scene do?