You’ve likely heard the term “chain of custody” but may not have thought much about it until prosecutors charged you with a crime. Your attorney or the court may keep advising you that you have to trust that police preserved the evidence that prosecutors plan to present at trial in an unbroken chain and that they used all the correct protocols in doing so. You may wonder what all that means.
Physical evidence is only admissible in court if collected, tagged, labeled, stored or preserved according to court rules and laws. The chain of custody must be unbroken to ensure that evidence collected by investigators and presented at trial is the same.
What are the links in the chain of custody of evidence?
There’s a lot of documenting who had the evidence, exactly what time it was moved from one point to another (for example, from a police officer’s possession in a sealed, labeled bag to an evidence storage facility). Any party who handles evidence must adequately document what they do with it.
It’s typical for anyone who handled physical evidence to testify at trial to establish that they maintained the appropriate chain of command. These witnesses may also face cross-examination if there’s any question about whether someone broke the chain of custody. The mere suggestion that someone broke the chain of custody can be enough to give jurors “reasonable doubt” that a defendant is guilty.
Evidence may be inadmissible if someone breaks the chain
Many rules apply to the chain of custody to ensure that a judge or jury won’t wrongly convict a defendant of a crime. An experienced criminal defense attorney will know how to ensure that anyone involved in their client’s arrest and prosecution acted complied with rules and laws every step of the way.
If someone failed to do, or if there was an issue with laboratory testing done on any evidence, then an attorney may be able to keep that evidence out of court. That could be the end of the prosecution’s case.