When securing the perimeter of a crime scene, how big should it be?

• A. Just around the immediate scene
• B. Wide and you can always make it smaller
• C. Large enough to cover city block
• D. As small as possible

Answer: (B)

The main idea here is that the first crime-scene perimeter should be wide enough to protect evidence and keep the scene uncontaminated, while still allowing investigators to control access and work effectively. Starting broad gives you room to account for all potential evidence and for movements of witnesses, bystanders, and responding units without stepping on or tainting things you’ll later collect. As the investigation unfolds and you determine exactly where the scene ends, you can tighten the boundary to focus resources and maintain a clear chain of custody, without compromising safety or the integrity of the evidence.

Choosing a boundary that’s just the immediate area risks missing relevant material in the surrounding spaces, and aiming for a very small area can expose evidence or people to unnecessary risk and complicate documentation. A boundary that’s excessively large wastes resources and makes management harder.