What is the primary reason for limiting the number of personnel who enter a crime scene?

Limiting the number of personnel who enter a crime scene is crucial primarily to preserve physical evidence. Crime scenes often contain important and fragile evidence that can be easily contaminated or destroyed. When too many people enter the scene, they may inadvertently alter or compromise evidence through their actions, such as disturbing the scene or leaving behind fingerprints, footprints, or other types of trace evidence. Preserving the integrity of the scene is vital for any subsequent investigation, as it allows forensic experts to collect and analyze evidence in its original context. This careful handling helps ensure that any findings can be reliably used in legal proceedings, making it an essential practice in criminal investigations.