Aug 12, 2019
Forensic DNA databases help solve crimes after the investigative trail has gone cold. Familial DNA and moderate stringency searches are logical extensions in cases where there is no exact DNA match, but these methods are not widely used. The authors present evidence from current practices in the United States, England, and Wales to support policymakers as they make decisions on the use and effects of familial and moderate stringency search.
Forensic DNA testing has helped law enforcement solve crimes, often long after the investigative trail has gone cold. Familial DNA and moderate stringency search protocols are logical extensions for cases where there is no exact DNA match. Although familial DNA searching is permissible in most states, it is used sparingly. Additionally, policies governing the use of familial searching lack consistency, and lawmakers might be uncertain about the procedure's effectiveness in solving or deterring crime — and about the unintended implications and legal, ethical, and practical barriers to its wider adoption.
The authors provide a baseline for criminal justice policymakers to better understand the ways in which familial DNA and moderate stringency testing are being used in the field today. Their findings are based on a U.S. survey and study of practices at state and local forensic laboratories and interviews with representatives of two states — California and Texas — that have used the technique in different ways. Additional qualitative interviews shed light on how the issues of privacy, public safety, and budget consciousness have shaped policies on familial DNA searching in England and Wales. The authors fill a knowledge gap for academics and practitioners about the history, prevalence, and typical practice of this technique and for policymakers seeking to make informed decisions on whether an expansion of the U.S. DNA databases would be acceptable by society in investigating how crimes can potentially be solved or prevented.