Forensic and legal requirements mandate that evidence be:

Positively identifying evidence and maintaining it in a chain of custody is crucial for the integrity of forensic investigations. This process ensures that the evidence is accurately linked to the crime scene and the individuals involved in the case. A well-documented chain of custody establishes a clear path of who handled the evidence and when, preventing any tampering or contamination. This meticulous documentation is vital in legal proceedings, as it helps to establish the credibility of the evidence presented in court.

In legal systems, evidence must be tracked from the moment it is collected until it is presented in court, ensuring that it is unaltered and reliable. Failing to maintain this chain can lead to challenges regarding the evidence's admissibility and authenticity, potentially undermining the entire prosecution or defense case.

The other options highlight practices that could compromise the integrity of evidence. Storing evidence without documentation or in undisclosed locations would make it difficult to verify its authenticity and reliability. Additionally, evidence that is deemed destroyable after a certain period does not consider the varying legal requirements and potential ongoing investigations, which may necessitate the retention of evidence beyond arbitrary time frames. Therefore, maintaining a clear and documented chain of custody is essential for ensuring the proper handling and use of evidence in forensic and legal contexts.