Final answer:
A legend is necessary for a crime scene sketch as it provides a key to understand the symbols and markings used in the sketch.
Step-by-step explanation:
A legend is necessary to have on your crime scene sketch. A legend provides a key that explains the symbols and markings used in the sketch. It helps investigators, forensic experts, and other personnel understand the various details and elements depicted in the sketch, such as measurements, evidence, and important areas. For example, if a specific symbol represents bloodstains, the legend would indicate what the symbol means and how to interpret it. Therefore, a legend is crucial for ensuring clear communication and accurate analysis of the crime scene.
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