Why is it important to photograph the front and back of a revolver's cylinder?

Photographing the front and back of a revolver's cylinder is essential for documenting gunshot residue (GSR) flash rings and caliber markings. This process allows investigators to capture critical forensic evidence that can indicate recent use of the firearm and help establish its role in a crime. The presence of GSR can suggest that the weapon was fired, which is crucial for linking a suspect to the crime scene. Additionally, the caliber markings found on the cylinder can help confirm the type of ammunition used, potentially connecting it with spent cartridges found at the scene or linking it to other crimes.

While assessing the overall condition of the firearm or measuring the weight of the cylinder may be relevant in some contexts, they do not provide the same level of forensic value in terms of linking the firearm to a specific incident. Similarly, the color of the gun, while useful for identification, does not offer the same critical insights as the ballistic characteristics documented through photographs of the cylinder. Therefore, focusing on GSR flash rings and caliber markings captures the most pertinent evidence for crime scene investigation.