Under what circumstance should the first responding officer move a piece of evidence?

The first responding officer may need to move a piece of evidence when they are charged with the responsibility of processing the scene for physical evidence. This scenario underscores the officer's crucial role in ensuring that all relevant evidence is collected and preserved in a systematic manner. If a piece of evidence is obstructing the process of gathering additional evidence or might be at risk of being contaminated or destroyed, moving it becomes essential to maintain the integrity of the investigation.

In this context, moving evidence can also facilitate the collection of other pieces of information or evidence that could be vital to the case. The officer must balance the importance of preserving evidence with practical considerations when addressing the scene dynamics. Each piece of evidence can provide important insights, thus ensuring that the scene is processed effectively is paramount to a successful investigation.

The other options involve responsibilities that are either situational or involve instructions from superiors, which do not directly relate to the necessity of processing evidence itself. While blocking an exit or securing the area are important safety considerations, they do not inherently justify the movement of evidence specifically for the purpose of evidence recovery and preservation.