Forensic Photographer Evidence Preservation & Analysis

Question 1

What is the first step in preserving physical evidence at a crime scene?

Accepted Answer

Secure and restrict access to the crime scene

Answer

The very first step in preserving physical evidence is to secure and restrict access to the crime scene. This action prevents contamination, destruction, or alteration of evidence by unauthorized personnel, which is paramount for maintaining the integrity of the scene. Establishing a perimeter and controlling entry ensures that evidence remains undisturbed until it can be properly documented and collected.

Question 2

Which type of evidence is most susceptible to degradation over time?

Accepted Answer

Biological evidence

Answer

Biological evidence, such as blood, semen, saliva, or tissue, is highly susceptible to degradation over time due to factors like bacterial growth, temperature fluctuations, and humidity. These environmental conditions can quickly break down organic material, making DNA analysis difficult or impossible. Proper collection and storage, often involving refrigeration or freezing, are critical to preserve its integrity for forensic analysis.

Question 3

Why is chain of custody documentation important in evidence handling?

Accepted Answer

To ensure evidence is not altered or compromised

Answer

Chain of custody documentation is critical in evidence handling to maintain a clear, unbroken record of everyone who has possessed the evidence from collection to court. This meticulous documentation proves that the evidence has not been tampered with, altered, or compromised at any point. It is essential for establishing the authenticity and admissibility of evidence in legal proceedings, preventing challenges to its integrity.

Question 4

What is the best method for preserving blood evidence on fabric?

Accepted Answer

Air dry and store in a paper bag

Answer

When preserving blood evidence on fabric, it is crucial to air dry it completely before packaging. This prevents the growth of mold and bacteria, which can degrade the blood and DNA. Storing it in a breathable paper bag further prevents moisture buildup and degradation, unlike airtight plastic bags which trap moisture and promote decomposition, compromising the evidence.

Question 5

Which forensic technique is used to analyze gunshot residue (GSR)?

Accepted Answer

Scanning Electron Microscopy (SEM)

Answer

Scanning Electron Microscopy (SEM) is the primary forensic technique used to analyze gunshot residue (GSR). SEM, often coupled with Energy Dispersive X-ray Spectroscopy (EDS), can detect the characteristic morphology and elemental composition (lead, barium, antimony) of GSR particles. This allows forensic scientists to confirm the presence of GSR on a suspect's hands or clothing, providing crucial evidence in shooting investigations.

(CFP) Certified Forensic Photographer Practice Test

(CFP) Certified Forensic Photographer Practice Test

Forensic Photographer Evidence Preservation & Analysis