What is “Chain of Custody” and why is it Important?

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Chain of Custody is a legal term of art that occasionally becomes an issue when dealing with the admissibility of evidence at trial.  Chain of custody is defined as the chronological documentation or paper trail that records the sequence of custody, control, transfer, analysis, and disposition of evidence. 

In order to admit fungible evidence, there typically must be evidence as to the item’s chain of custody to ensure the item is what it purports to be.  Fungible items are items that are interchangeable with each other.  For example, marijuana seized as part of drug bust A could theoretically appear to be visually identical to marijuana seized from drug bust B.  In a trial regarding drug bust A, there should be a proper chain of custody to ensure that the marijuana seized from drug bust A is admitted instead of the marijuana seized from drug bust B.  In order to admit the marijuana as evidence from drug bust A, the prosecutor would have to show with reasonable certainty that the evidence offered is the same evidence that was seized as part of drug bust A and that there has been no tampering or substitution of the evidence.

What does a proper chain of custody look like?  Let’s take our example involving the marijuana seized from drug bust A the chain would look something like this:

  1. The law enforcement officer that seized the marijuana at the scene;
  2. The officer or evidence technician that transported the marijuana from the scene to the evidence room;
  3. The person that checked in the evidence at the evidence room;
  4. The chemist that checked the marijuana out of the evidence room for testing to ensure that the marijuana is indeed marijuana;
  5. The person that checked the evidence in at the property room after testing is complete;
  6. The law enforcement officer that checked the marijuana out of the evidence room and transported the marijuana to the courtroom for trial.

Why is chain of custody important?  If the chain of custody is broken, meaning that somewhere along the way there was improper handling, documentation, transfer, or storage of the evidence, there is a chance that the evidence may have been tampered with.  There is also a chance that the evidence may have inadvertently been swapped with similar fungible evidence. 

To further illustrate, let’s assume that the evidence seized from drug bust A and drug bust B appear visually identical.  The evidence in both cases is packaged in plastic bags. Both bags contain a green leafy substance, and both bags are approximately the same weight.  However, in this hypothetical, the person checking the evidence into the evidence room mislabels the bags, so that the evidence seized from drug bust A is labeled as the evidence seized from drug bust B and vice versa.  The evidence seized from drug bust A is chemically tested and as expected, tests as marijuana.  The evidence from drug bust B is chemically tested and actually comes back as hemp, with no THC, and is therefore a legal substance.  Because the evidence was mislabeled, the defendants in drug bust A would be wrongfully exonerated by the evidence from drug bust B, while the defendants in drug bust B would be wrongfully prosecuted with the evidence from drug bust A.   

Do you have a case in which chain of custody at issue?  Contact the experienced Indianapolis criminal defense attorneys at Banks and Brower anytime at (317) 870-0019 or by email at info@banksbrower.com.