Chain of Custody

Chain of custody is a concept in the study and application of law that applies to the proper handling of evidence within a criminal proceeding. It refers to the ability to positively guarantee the identity, integrity, and chronological history of evidence from the point of acquisition through to examination and testimony. The sensitive nature of evidence, as used in a court of law to convict a person or persons of a crime, requires strict custodial procedures to be followed in a precise and careful manner to avoid later allegations of tampering or misconduct. These custodial procedures are carefully logged, documented, and attested via signature by every identifiable person at every stage of custody, thus creating a probable chain of custody that can be traced back to the point of acquisition. Thus, the chain of custody becomes a legal, chronological, written record of those individuals who have had custody of the evidence from the point of its initial acquisition until its final disposition.

The chain of custody begins when evidence is collected and is maintained until the evidence is disposed of. In a proper chain of custody, an identifiable person must always have documented physical custody of a piece of evidence. This documentation ensures continuous accountability, which is important because if not properly maintained, it may render evidence inadmissible in a court of law.

According to N.J. Practice, Criminal Procedure by Honorable Leonard Arnold, J.S.C. (West Publishing), Volume 32, Chapter 21, Section 1034, a party seeking to introduce an item of physical evidence must prove that the item was taken from a particular person or place that makes the item relevant as evidence in the trial. Such proof is provided by testimony identifying the item as having been taken from that person or place, and by evidence tracing custody of the item from the time it was taken until it is offered in evidence. This latter evidence is necessary to avoid any claim of substitution or tampering (State v. Johnson, 1966).

The very first link in the chain of custody is the investigator, officer, or detective who takes custody of the evidence at the scene of the crime or search warrant, and who then carefully documents its position, collection, and handling. Custody of the evidence is then signed over to an evidence clerk for storage in a secure place. All investigators, officers, or detectives who recover physical evidence must turn that evidence over to the evidence clerk, who is then legally responsible for the evidence from that time forward until trial.

In cases where evidence must be submitted to a laboratory for examination, the evidence is signed out by an investigator or other person empowered by the prosecutor, thereby becoming the new custodian. This transaction is logged by the evidence clerk, and signed by the person taking custody of the evidence. It is then promptly delivered directly to the laboratory, where custody changes hands again. Documentation must be obtained at every step of the way, carefully logging times; dates; case numbers; the nature of the evidence; and, more importantly, the names of the custodians. At all times, documentation must be signed by both parties involved in the exchange in order to maintain a proper chain of custody and maintain the integrity of the evidence.

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