The Chain of Custody of Physical Evidence

"He directed her to her testimony at the preliminary hearing. She had described then how she had collected the fingernail cuttings and scrapings and put them in paper bindles. Now they were in clear boxes. When had they been transferred? Mary Pierson said had no independent recollection. It was a phrase that was becoming more familiar with the trial." -Weinberg (p. 287)

During the time of the investigation of a crime scene it is pertinent to keep a chain a custody of any physical evidence collected. This provides a means of monitoring where and when the evidence is being stored. If the chain of custody is improperly managed then the evidence collected at the crime scene could be thought that it it could have been potentially tampered with. In cases where DNA, a piece of physical evidence, is the only evidence that links the defendant to the crime scene it is crucial that this evidence is held under the proper protocol and management. Because if it isn't properly cares then evidence used court can be dismissed. Taking a forensic entomology class at Loyola, I learned that when investigating a crime scene it is critical to annotate everything done in and out of the crime scene. So that there are no inconsistencies and have the forensic eyewitness report allowed in court.

The chain of custody described by the SART Toolkit says, "To maintain chain of custody, you must preserve evidence from the time it is collected to the time it is presented in court. To prove the chain of custody, and ultimately show that the evidence has remained intact, prosecutors generally need service providers who can testify." These service providers are typically the forensic scientists or trained policemen that can explain:

  • That the evidence offered in court is the same evidence they collected or received.

  • the time and date the evidence was received or transferred to another provider.

  • That there was no tampering with the item while it was in custody

All these components are critical for a service provider to have. Not only will they explain that the procedures done in the crime were up to protocol standards under oath but also convince the jury that the evidence is reliable. This requires a lot of understanding of the scientific methods used as well as have ability to be well spoken. The art of testifying is can be difficult and daunting for most people. Withstanding the badgering by defense lawyers, and surviving shots made towards your credibility as a scientist are some qualities that not all service providers have. That is why its important when dealing with trials, like the Frediani case, to have service providers that hold their own against sharks of defense lawyers.

Media involving the chain of custody:


Dr. River's Forensic Entomology Class

The Chain of Custody of Physical Evidence

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