NIST Corner: Biological Evidence Preservation
Written by Shannan Williams   

Far too often, we hear unsettling stories about individuals who were wrongfully convicted and later exonerated after the retesting of old evidence. Each case leaves the public wondering what could have been done to stop an innocent person from being imprisoned for years, and in many cases, decades.

Although the circumstances surrounding these individuals’ convictions are varied, in general they share two common factors: the exculpatory evidence was 1) located and 2) properly preserved to allow for testing.

NIST has published a series of reports to help property and evidence custodians “ensure the integrity, prevent the loss, and reduce the premature destruction” of evidence. These guides provide valuable information to ensure that evidence is stored and tracked appropriately. The latest publication, Biological Evidence Preservation: Considerations for Policy Makers, contains nine recommendations for aligning state and local laws and policies with best practices for handling biological evidence.

“While 43 states and the District of Columbia have enacted statutes related to the preservation of biological evidence, policies and procedures can be enacted in states that currently have no laws and for those looking to make improvements,” states the introduction. The guide is intended for anyone who is responsible for developing policy, including legislators, judges, police chiefs, crime lab directors, and property and evidence managers.

The policy makers’ guide is a product of the NIST and National Institute of Justice-sponsored Technical Working Group on Biological Evidence Preservation. It examines existing state statutes, current trends, laws, scientific literature, and expert opinions to recommend practices for policy makers to improve the preservation of biological evidence.

“The working group members felt that a guide for policy makers would extend the value of the 2013 best practices publication,” said Melissa Taylor, a forensic science project manager in the NIST Special Programs Office. “We know that our 2013 handbook on best practices has made an impact in the forensic science community. We also know that best practices will be implemented in a more complete fashion with the backing of legislation and policies.”

The National Commission on Forensic Science has indicated that biological evidence preservation is a topic of concern. On April 30, it heard a panel discussion on issues related to evidence preservation and retention. One of the panel speakers, Steve Campbell, a retired police chief and board member of the International Association for Property and Evidence (IAPE), called the 2013 handbook, “the holy grail for retaining evidence.” The association uses the guide in its training courses.

Commission member Cecelia Crouse, who is the director of the Palm Beach County Sheriff’s Office Crime Lab, also endorsed the 2013 handbook stating that it was a, “wonderful supportive document,” and explaining that it was used to help procure a brand new evidence storage facility.

The new Biological Evidence Preservation: Considerations for Policy Makers guide can enable much more progress toward achieving appropriate biological evidence preservation nationwide.

The guide suggests that all jurisdictions use a uniform definition for biological evidence and discusses and summarizes nine specific recommendations. The recommended definition (recommendation 1) is:

“Evidence commonly recovered during a criminal investigation in the form of skin, hair, tissue, bones, teeth, blood, semen, or other bodily fluids, which may include samples of biological materials, or evidence items containing biological material.”

Seven recommendations pertain to evidence storage and disposition. The first two of these, recommendations 2 and 3, address concern that some states require a petition to be filed to request that biological evidence be preserved after convictions. Only 31 states require automatic retention of biological evidence. The policy recommendation is that each state should establish rules or policies for automatic biological evidence preservation. The publication provides recommended timeframes for specific types of crimes.

Recommendation 4 applies to storage conditions, and recommendation 5 suggests statutory authority for a board or commission to enforce standards consistent with best practices for biological evidence preservation. Recommendations 6 and 7 focus on disposition of biological evidence.

Two recommendations pertain to denial of access to biological evidence. Recommendation 8 specifies that laws in each state should provide a defendant with the opportunity to seek a remedy in cases where a judge determines that a denial of access has occurred. Recommendation 9 says that courts should consider ordering evidence custodians to conduct a search for missing evidence, and that courts should consider ordering a report on the search details and result.

About the Author

This e-mail address is being protected from spam bots, you need JavaScript enabled to view it is a forensic science research project manager in the NIST Special Programs Office.

For More Information

Biological Evidence Preservation: Considerations for Policy Makers can be downloaded at:

See more biological evidence management resources at:

Information on the Technical Working Group on Biological Evidence Preservation can be found at:

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