How should the integrity of a crime scene be maintained?

Maintaining the integrity of a crime scene is crucial for the proper collection and analysis of evidence. Keeping the crime scene unmarked and untouched ensures that any physical evidence remains in its original state, preventing contamination or alteration that could compromise an investigation. An untouched scene provides forensic teams with the best opportunity to gather accurate data and preserve the context of where and how the events took place.

Each of the other options could potentially jeopardize the evidence collected at the scene. Allowing anyone to enter for investigation would risk inappropriate handling of evidence or accidental damage, while making changes for safety reasons could lead to altering critical elements of the scene without proper documentation. Placing non-official security personnel in the area might introduce unauthorized individuals who lack the necessary training or authority to safeguard the evidence correctly. Thus, the best approach to preserving crime scene integrity is to ensure it remains unmarked and untouched by anyone who is not directly involved in the investigation.