Los Angeles Criminal Defense Firm

Chain of Custody

Chain of custody refers to the movement and location of evidence from the moment it was collected to the time it is presented at trial. A proper Chain of Custody must establish:

  • Which person / officer / investigator collected the evidence and what did that person do with it for example, did the investigator package the evidence so it prevents tampering and distinguishes it from other evidence seized at the same crime scene;
  • Date, time, and place the evidence was collected;
  • How the evidence was collected - what procedures and methods were used to collect it and what safeguards were used to protect the evidence;
  • How the evidence was tagged, labeled or marked;
  • Where the officer / investigator stored the evidence and properly logged it.
  • When and by whom the evidence is moved, transferred, or tested.

Testimony and documentation are used to authenticate evidence – to establish that the evidence is what it is claimed to be. Evidence that cannot be authenticated may not be reliable or trustworthy and will not be admitted at a criminal trial. Often, prosecutors must establish chain of custody because criminal prosecutions depend on evidence gathered by police officers at the crime scene. Criminal defense attorneys generally challenge the chain of custody presented by prosecutors. If a criminal defense attorney succeeds in showing a break in the chain of custody then the prosecutor may be precluded from presenting that evidence to the jury.