What is the first step a forensic scientist should take upon arriving at a crime scene?

The first step a forensic scientist should take upon arriving at a crime scene is to photograph all evidence in its original place. This is crucial because proper documentation through photography preserves a visual record of the scene as it was found. These images serve multiple purposes: they can help establish context, provide insights into the events that took place, and are critical for later reports or court presentations.

Photographing the scene before any evidence is moved ensures that investigators have a clear reference point for the location and condition of all physical evidence. This is important for chain of custody and can help prevent any claims of evidence tampering. It also aids in the reconstruction of the crime scene during the investigation.

Alternative actions such as turning off the power, unplugging network connections, or gathering up physical evidence are important, but they are secondary to this initial documentation step. Modifying the crime scene without first recording it can compromise the investigation, as the original context of the evidence could be lost. Thus, photography is the key first action to ensure that the integrity of the scene is maintained for further analysis and legal scrutiny.