U.S. flag

An official website of the United States government, Department of Justice.

Forensic Familial and Moderate Stringency DNA Searches: Policies and Practices in the U.S., England, and Wales

NCJ Number
Date Published
May 2019
12 pages
This is the Summary Overview of the findings and methodology of a study of practices on familial DNA and moderate stringency DNA testing and their effects.

Familial DNA searching and moderate stringency search protocols could be a productive extension of the DNA investigative tool for cases in which there is no exact DNA match in the national network of forensic DNA databases. Yet, despite anecdotal reports of its use and efficacy, little is known about these search policies or practices. In order to aid policymakers, this study examined practices on familial DNA and moderate stringency DNA testing. The study consisted of the following four components: 1) a literature review on familial and moderate stringency DNA searching; 2) a survey of varying familial and moderate stringency DNA policies and data from state and local forensic laboratories; 3) interviews with representatives of two states (California and Texas) that have used this technique in different ways; and 4) interviews with English and Welsh stakeholders. This resulted in useful guidance to policymakers who are considering policies on familial and moderate stringency DNA searches. The study found that there are legitimate concerns about privacy issues if familial DNA testing should become widespread; however, it is rarely used in the United States. Given the reported work backlogs for conventional DNA testing in the United States, the study concludes that the expansion of conventional DNA capabilities is probably the best short-term strategy. Although California and Texas were found to have different models for familial DNA searches, both states have restricted its use to cases involving serious threats to public safety. England and Wales have rarely but successfully used familial DNA searches. Recommendations are offered for future research on this issue.

Date Published: May 1, 2019