What action is legally required by police when establishing a crime scene in a public setting?

When police establish a crime scene in a public setting, one of their primary legal obligations is to restrict access to the area. This action is crucial for several reasons. It helps preserve the integrity of the crime scene, ensuring that potential evidence is not contaminated or tampered with by unauthorised individuals. Controlling access allows investigators to systematically gather evidence, conduct thorough examinations, and maintain the safety of both the public and the individuals involved in the incident.

In a legal context, restricting access is also significant for the protection of citizens' rights and ensures that the investigation can proceed without interference. This measure aids in maintaining the chain of custody for any evidence collected, which is essential for ensuring that the findings can be used effectively in legal proceedings.

Other options such as notifying the media or arresting anyone nearby do not constitute legal requirements for police when establishing a crime scene. Documenting the scene is important but primarily serves as a supplementary action rather than a mandatory initial step. Access control stands out as a fundamental duty in the process of ensuring a proper investigation takes place.