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Understanding Familial DNA Searching: Policies, Procedures, and Potential Impact, Summary Overview

NCJ Number
Date Published
August 2017
23 pages
Since little research documents current practices and outcomes in the use of familial DNA searching (FDS) in criminal investigations, the current research begins closing this knowledge gap by conducting a multi-phase, mixed-methods study of FDS policies and practices in the United States.
Traditionally, DNA profiling has been used to obtain exact matches between unknown genetic samples from crime scenes to those obtained from convicted offenders, arrestees, or crime-scene samples from other cases; however, the ability to identify partial matches or close associations through lower stringency searches enables the identification of potential family relationships, given the inherited nature of DNA and the fact that family members have more genetic similarities than non-related individuals. This suggests that a particular crime-scene DNA sample that does not have an exact match in the Federal DNA database Combined DNA Index System (CODIS) may show a family relationship to a person whose DNA is in CODIS. CODIS can uncover partial matches fortuitously, but it is not designed to identify familial matches. In attempting to overcome this limitation, some jurisdictions have sought separate software and genetic algorithms to identify family relationships in DNA searches. Ethical considerations have been raised regarding FDS. They have focused on privacy and family issues, such as whether law enforcement should be investigating and labeling innocent family members as suspects based solely on relatedness; e.g., in a case where there are multiple brothers being investigated based on FDA and only one is guilty. The current study provides a balanced examination of controversies and considerations from thought leaders on this issue; a national portrait of FDS policies and practices; an in-depth exploration of how it is used within States with varying philosophies and procedures regarding FDS; and a cost model on expenditures and cost savings related to FDS. 3 exhibits and 34 references

Date Published: August 1, 2017