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Thu, Jan 02


Learn more about Familial Searching

What is Familial DNA and Why is it important?

Legislation: S2480 An Act permitting familial searching and partial DNA matches in investigating certain unresolved crimes

What is Familial DNA and Why is it important?
What is Familial DNA and Why is it important?

Time & Location

Jan 02, 2025, 4:00 PM

Learn more about Familial Searching

About the Event

Familial searching (FS) is an additional search of a DNA profile in a law enforcement DNA database that is conducted after a routine search does not identify any profile matches.

*Potential to identify close biological relatives of the source of an unknown forensic profile obtained from crime scene evidence

*Process entails ranking potential candidates in the database using autosomal STR data followed by lineage marker (Y-STR) testing to reduce the candidate list to individuals who have a high probability of being a relative of the donor source of the evidence DNA profile

*Essentially another tool for utilizing a DNA database to generate investigative leads and identify perpetrators of crime, and just as importantly, to help exonerate wrongfully convicted individuals

Why hasn't a policy been implemented?

An absence of clear guidance and documentation of the policies and practices currently employed to ensure proper FS utilization, despite previously federally funded resources designed to provide direction concerning FS policy, including an educational resource and a discussion panel.

Some additional facts:

*To date there have been no known cases where a false association has been made following the two-step process

*There have been no legal challenges that specifically pertain to the use of FS in these states, in fact several of the FS successes have gone to jury trial, and no legal challenges were lodged against using FS in the investigation

Success Rates:

*Of the 90 FS cases in Denver to date, 23 of the database searches resulted in identification of a true biological relative of the evidentiary sample (a success rate of 26%)

*California’s metric is of the 66 FS cases, 26 resulted in identification (or a 39% success rate)

There are approximately 326,000 unidentified forensic profiles in NDIS that have not been associated with aiding an investigation, if the success rate of FS is maintained at the same rate as that in Denver (26%) then one could expect FS to produce valuable investigative leads in about 84,760 additional cases.

States conducting FS:  


New York


Colorado (Denver)










California Department of Justice FS policy is posted at

Denver FS policy can be found at on the DNA resource page

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