Answer:
One of the most important aspects of an evidence log is to document the chain of custody for the evidence.
Step-by-step explanation:
A simple way to understand what was said in the question is to think of a crime you have seen portrayed on a TV show. The police find evidence in the crime scene, that is, anything that may reveal who committed the crime. Sometimes they will collect objects to take with them, other times they will take pictures of the scene. All of that is evidence.
However, there must be a careful handling of that evidence, otherwise it may be lost or tampered with. That is what the evidence log is for. In an evidence log, all information regarding that evidence will be noted down. Who had it before, who has it now, when the evidence changed hands, etc. For instance, if an evidence is taken to the lab, that fact is noted down. If later it is taken to storage, this is also noted down. That way, a chain of custody is created, that is, we have information that shows each step of handling that evidence.