Forensic DNA databases have received an inordinate amount of academic and judicial attention. From their inception, numerous scholars, advocates, and judges have wrestled with the proper reach of DNA collection, retention, and search policies. Central to these debates are concerns about racial equity in forensic genetic practices. Yet when such questions arise, critics typically just assert that forensic DNA databases are not demographically representative. Such assertions are expressed in vague or conclusory terms, without a citation to actual data or even to concrete estimates about the actual composition of DNA databases.

This Article endeavors to fill these gaps in the literature by providing demographic information about the composition of forensic DNA databases. We draw upon two sources. First, we obtained data from states in response to our requests under freedom of information laws. Second, we devised an original estimate based on public information about each state’s DNA collection policies and the demographic data that matches those policies. In other words, we reverse-engineered the national DNA database. Both approaches revealed dramatic disparities in the racial composition of DNA databases, including that DNA profiles from Black persons are collected at two to three times the rate of White persons.

We then use our data on the actual and estimated racial composition of DNA databases to identify and illuminate four questions fundamental to forensic DNA policy. First, the data centers racial justice concerns as critical to debates about the proper scope of collection and search policies, as well as the impact of forensic DNA database practices more generally. Second, the data casts light on the significance, determinacy, and stability of race and ethnicity as meaningful biological and social categories. Third, the data provides insight into the advantages and disadvantages of choosing among architectural approaches when collecting, storing, and searching sensitive data such as genetic profiles. And finally, the data prompts questions about genetic privacy more generally, including how to weigh the significance of criminal justice practices in an increasingly genetically transparent society.