A/An _____ is the explanation of symbols used to identify objects in a crime scene sketch.

The correct answer is "legend" because it serves as a critical component of a crime scene sketch, providing clarity about the symbols and markings used within the diagram. A legend lists and explains each symbol, allowing anyone who views the sketch to understand what specific features, objects, or locations are represented. This ensures that the sketch is not only a visual representation of the scene but also a complete and comprehensible document that can assist in investigations and legal proceedings.

In the context of crime scene investigation, a well-prepared legend is essential for maintaining the integrity and usability of evidence over time. By clearly defining each symbol, investigators can accurately communicate important aspects of the scene to others, making it easier to reconstruct events or provide testimony in court. The legend is typically found on the same page as the sketch, complementing it and enhancing its value as a reference tool.