CSI - Crime Scene Investigator Evidence Collection and Preservation Questions and Answers — Questions and Answers
Question 1: A wet bloodstained garment is collected at a crime scene. Which of the following represents the proper procedure for packaging this evidence to prevent degradation?
- Seal the wet garment in a plastic bag to retain moisture.
- Allow the garment to air-dry completely in a secure, well-ventilated area before packaging it in a paper bag. (Correct answer)
- Use a hair dryer on a high heat setting to speed up the drying process before packaging.
- Fold the wet garment neatly and place it directly into a cardboard box, sealing it immediately.
Correct answer: Allow the garment to air-dry completely in a secure, well-ventilated area before packaging it in a paper bag.
Biological evidence, such as a bloodstained garment, must be thoroughly air-dried before being packaged in a breathable container like a paper bag. Sealing a wet item in a plastic bag traps moisture, which promotes the growth of mold and bacteria, leading to the degradation of crucial DNA evidence. Using heat to dry the garment can also damage or alter the biological material. Therefore, air-drying is the correct method to preserve the integrity of the evidence.
Question 2: Which of the following BEST describes the primary purpose of the chain of custody?
- To provide a detailed description of the evidence for the final crime scene report.
- To document the chronological history of the handling, transfer, and storage of evidence to ensure its integrity. (Correct answer)
- To assign a unique identification number to each piece of evidence collected at the scene.
- To record the initial observations of the first responding officer upon arrival at the crime scene.
Correct answer: To document the chronological history of the handling, transfer, and storage of evidence to ensure its integrity.
The chain of custody is a critical process that documents every person who has handled a piece of evidence from the moment of its collection until its presentation in court. This chronological record ensures the authenticity and integrity of the evidence, proving that it has not been tampered with, altered, or substituted. While describing evidence, assigning numbers, and recording initial observations are all parts of crime scene investigation, the specific function of the chain of custody is to track possession and handling.
Question 3: At a homicide scene, an investigator discovers a smartphone lying next to the victim. The phone is powered on. What is the most appropriate immediate action for the investigator to take regarding the phone?
- Immediately power the device off to preserve battery life and prevent remote wiping.
- Attempt to unlock the device to search for immediate clues about the perpetrator.
- Leave the device powered on, connect it to a charger if possible, and place it in a Faraday bag to block network signals. (Correct answer)
- Photograph the device and then remove the battery to secure the data.
Correct answer: Leave the device powered on, connect it to a charger if possible, and place it in a Faraday bag to block network signals.
When a digital device like a smartphone is found powered on, the best practice is to keep it powered on to preserve volatile data that exists only while the device has power. Powering it off could lead to data loss. The device should be isolated from networks by placing it in a Faraday bag or setting it to airplane mode to prevent remote wiping or alteration of data. Connecting it to a power source ensures the volatile memory is not lost due to a dead battery.
Question 4: Which of the following is the most appropriate packaging for arson evidence, such as a piece of charred carpet suspected of containing an accelerant?
- A porous paper bag.
- A sealed plastic evidence bag.
- A clean, unused metal can with an airtight lid. (Correct answer)
- A standard cardboard box.
Correct answer: A clean, unused metal can with an airtight lid.
Evidence from a suspected arson scene must be packaged in an airtight container to prevent the volatile accelerant residues from evaporating. A clean, unused metal paint can or a glass jar with an airtight lid is the standard and most effective container for this purpose. Paper and plastic bags are not suitable as they are porous and will allow the volatile compounds to dissipate, destroying the evidentiary value.
Question 5: An investigator is collecting a firearm at a crime scene. Which of the following actions should be AVOIDED to preserve potential trace evidence and for safety?
- Photographing the firearm in its original position before moving it.
- Unloading the firearm and making it safe before packaging.
- Placing a pencil or other object into the barrel to pick it up. (Correct answer)
- Packaging the firearm in a sturdy cardboard box and securing it with zip ties.
Correct answer: Placing a pencil or other object into the barrel to pick it up.
Placing any object, including a pencil, inside the barrel of a firearm can contaminate it and destroy valuable trace evidence, such as DNA or microscopic striations crucial for ballistics analysis. It is a fundamentally incorrect and unsafe handling procedure. The proper procedure involves handling the weapon by its textured surfaces (like the grip), photographing it, unloading it for safety, and securing it in a rigid container like a gun box.
Question 6: When documenting a crime scene, what is the primary reason for taking overall, mid-range, and close-up photographs of evidence?
- To fulfill a departmental quota for the number of photos taken at a scene.
- To provide artistic and visually appealing images for the case file.
- To show the evidence in its original location, its relationship to the overall scene, and its specific details. (Correct answer)
- To test the functionality of the camera's different zoom lenses.
Correct answer: To show the evidence in its original location, its relationship to the overall scene, and its specific details.
The three-tiered approach to crime scene photography (overall, mid-range, and close-up) is a systematic method to properly document evidence. Overall photos capture the entire scene to show where it happened. Mid-range photos show the relationship between a piece of evidence and other items or landmarks in the scene. Close-up photos (taken with and without a scale) reveal the fine details of the individual piece of evidence itself. This progression provides a complete visual record for investigators and the court.
CSI - Crime Scene Investigator Evidence Collection and Preservation Questions and Answers
A wet bloodstained garment is collected at a crime scene.
Which of the following represents the proper procedure for packaging this evidence to prevent degradation?