What is the primary function of the "chain of custody" in criminal investigations?

The primary function of the "chain of custody" in criminal investigations is to preserve the integrity of evidence. This concept refers to the process of maintaining and documenting the handling of evidence from the time it is collected until it is presented in court. A robust chain of custody ensures that evidence is not altered, tampered with, or contaminated, which is crucial for establishing its reliability and authenticity. This process includes careful documentation of who collected the evidence, how it was stored, and any transfers that occurred, thus ensuring that all handling of the evidence can be accounted for.

Maintaining the integrity of the evidence is vital for the prosecution of a case, as any break in the chain of custody can challenge the admissibility of the evidence in court. If the evidence cannot be trusted due to mishandling or a lack of proper documentation, it may lead to reasonable doubt regarding the guilt of the accused and can significantly impact the outcome of the trial. This principle is foundational in legal proceedings to uphold the standards of justice and fairness.