Informed consent is the first, and most key, safeguard to forensic genealogy searches to solve long-unsolved crimes, according to three bioethicists from the National Institutes of Health.

The legal questions around the Fourth Amendment are simpler than the ethical concerns, according to the NIH scientists’ paper in the Annals of Internal Medicine.

“Criminal genealogy searching is a valuable tool but raises important ethical issues that should be examined before the practice is widely adopted,” they write. “Better informed consent would alleviate some of these concerns, particularly if genealogy services actively highlight the possibility of data use for forensic purposes—and the implications for the individual and his or her relatives.”

The NIH take: most users do not yet know of the potential of the forensic use of their genes, even if provisions include it in the terms of service.

But multiple studies indicate that users have shown acceptance of the use of their biomedical data for scientific research purposes—if their permission is sought first.

The forensic applications are a bit touchier, however, and consumers should especially be made aware of what their DNA code may mean in probes of crimes of the past—or future.

“Individuals hold different views on whether potential crime solving justifies the repurposing of genealogy data, indirectly implicating relatives, or inconveniencing innocent suspects,” write the bioethicists. “Given this diversity of opinion, it is important for users to be alerted to the possibility of their data being used in criminal investigations.”

The op-ed analysis cites the high-profile arrest of Joseph James DeAngelo, the accused Golden State Killer, in California last month.

That kind of decades-long cold case investigation—the dead-end search for the East Area Rapist/Original Night Stalker/Diamond Knot Killer/Visalia Ransacker that led to DeAngelo through the public genealogy database GEDmatch—should be the primary use of genetic genealogy in criminal investigation, according to the paper.

The DNA searches—which can point detectives to persons of interest—should be fully complemented by other avenues of investigation.

“We recommend using forensic genealogy as an investigative tool rather than a primary source of evidence of criminal wrongdoing,” they write. “Likewise, justice concerns might warrant limiting criminal genealogy searching to cold cases involving crimes in which other investigative methods have failed.”

GEDmatch was used in not only the Golden State Killer case, but also a handful of other high-profile breakthroughs in the last year-plus, including: the Buck Skin Girl of Ohio, and the trail of the “Chameleon Killer” Terry Peder Rasmussen, connected through an abandoned abused girl back to New Hampshire’s infamous Bear Brook Murders.

However, the privacy concerns have prompted a kind of backlash of public opinion in the wake of the capture of the man accused of being the Golden State Killer. Indeed, one of the databases that has been used to catch some killers announced it was shutting its search operations down, partly because of high-profile cases like the DeAngelo arrest.