Restrictions on Law Enforcement Use of Commercial Genetic Genealogy Databases

Restrictions on Law Enforcement Use of Commercial Genetic Genealogy Databases concern the gap between what DNA technology might make possible and what investigators can access under platform rules and legal protections. The book contrasts the established public forensic system, built around CODIS, with commercial databases that might reveal a perpetrator through relatives, but whose companies will not work with law enforcement. For Michelle McNamara, that gap becomes a locked door: the killer’s profile exists, yet the biological sample and authorized route needed to search commercial databases do not.

From Forensic Samples to Searchable Profiles

The prospect of using genetic information for investigations had changed dramatically over a few decades. When the Orange County Crime Lab began incorporating DNA testing in the early 1990s, one case could take a criminalist up to four weeks. Testing required a substantial, well-preserved sample—a bloodstain about the size of a quarter, for example. By the time described in the book, a small scattering of skin cells could yield a genetic fingerprint within hours. The contrast matters to the database question: technological advances expanded what could be obtained from crime-scene material, but did not by themselves determine where that information could be searched or who could search it.

The public system developed through a different institutional route. The DNA Identification Act of 1994 established the FBI’s authority to maintain a national database, and CODIS became the upper level of a forensic network. Local crime labs entered unknown crime-scene samples and certain collected suspect samples into state databases; those systems verified and compared profiles within each state before passing them up to CODIS. In California, entries were automatically uploaded every Tuesday, while the state also collected DNA from jails and courthouses. This layered process made the comparison of law-enforcement-held profiles systematic, but it was not the same as searching commercial genealogical records for a suspect’s relatives.

That distinction was especially visible in the mid-1990s, when the system was still developing. Labs then relied on RFLP analysis, a laborious profiling method, and the database infrastructure was neither speedy nor mature. The Orange County Crime Lab was considered ahead of the pack: a 1995 account described local prosecutors, detectives, and criminalists submitting DNA from old unsolved cases to a new California Department of Justice lab in Berkeley, where four thousand profiles of known violent offenders, many of them sex offenders, were held. The state database was in its infancy, and the work of submitting older evidence helped it grow. These efforts show how official databases could expand through coordinated public institutions; the commercial services raised a separate question of access and permission.

The Promise and the Barrier

Commercial genealogy databases offered a different investigative possibility. If investigators could compare a killer’s genetic material—not merely selected markers—with the records held by such a service, a match to a second- or third-degree cousin might point toward the perpetrator. The database would not necessarily identify the killer directly; a relative’s connection could instead give investigators a lead from which to work toward an identity. The book presents this as a potentially powerful way to direct inquiries, not as a result already achieved in this case.

The companies’ policies blocked that route. The book states that neither 23andMe nor Ancestry.com would work with law enforcement, citing privacy concerns and their terms of service. It also frames the barrier in legal terms, referring to privacy and illegal-search-and-seizure issues under the Fourth Amendment to the United States Constitution. The restriction is therefore not simply a technical limitation: commercial databases may contain information useful to an investigation, while their terms and the legal questions around searching them limit investigators’ access. The account does not resolve the boundaries of those rules or establish that a particular search would be lawful.

Michelle McNamara’s Proposed Route

Michelle McNamara wanted to enter the killer’s DNA into rapidly expanding commercial databases and was willing to disregard their terms of use. Yet she did not possess the killer’s spit or a swab—materials of the sort a company’s ordinary process required. What she had was a DNA profile on paper. A scientist friend of Billy Jensen’s said there was a way around that practical obstacle, but the passage does not describe a completed search or identify a resulting relative. The proposal remains at the edge of possibility: a workaround had been suggested, while the needed biological sample was absent and the privacy and legal objections remained.

The account thus separates technical feasibility from permission and evidence. A paper profile may preserve identifying genetic information, but it is not the same thing as the physical sample a commercial service asks a customer to submit. Even if that gap could be bridged, the company’s terms and constitutional concerns would still have to be confronted. The book records Michelle’s willingness to push past the companies’ rules without presenting that willingness as proof that a search occurred or that its legality was settled.

Investigative Work Beyond the Database

Michelle’s other research methods show how much investigative labor could proceed without access to commercial genetic databases. As official case files arrived while she worked on a feature for Los Angeles magazine, she read them and built an index of people, places, and objects named in the reports. The index was meant to make investigative details easier to locate, distinguish people who might otherwise be confused, trace geographic movement, and identify overlapping names or possible connections among victims.

She later bought two high-volume digital scanners so the materials could be made searchable and more readily available. Much of the scanned material had not been seen by active investigators such as Paul Holes, Ken Clark, and Erika Hutchcraft; sharing it could also return useful work to investigators who had assisted her. These methods did not substitute for a DNA database search, but they demonstrate another way to assemble and circulate leads: organize the documentary record, make it searchable, and connect information across files. Against that painstaking archival work, the commercial database’s promise is both striking and limited—a possible shortcut to a family connection, held behind rules and unresolved legal questions.