In April 2018, California authorities revealed that they’d used a novel investigative technique to arrest a man they called the Golden State Killer, a serial murderer who’d escaped capture for decades.

For the first time, police had submitted DNA from a crime scene into a consumer DNA database, where information about distant relatives helped them identify a suspect.

The announcement kindled a revolution in forensics that has since helped solve more than 50 rapes and homicides in 29 states.

But earlier this year, that online database changed its privacy policy to restrict law enforcement searches, and since then, these cold cases have become much harder to crack. The change is allowing some criminals who could be identified and caught to remain undetected and unpunished, authorities say.

“There are cases that won’t get solved or will take longer to solve,” Lori Napolitano, the chief of forensic services at the Florida Department of Law Enforcement, said.

The switch was imposed by GEDmatch, a free website where people share their DNA profiles in hopes of finding relatives. The company had faced criticism for allowing police to search profiles without users’ permission, and decided that it would rather make sure members understood explicitly how investigators were using the site. So, it altered its terms of service to automatically exclude all members from law enforcement searches and left it to them to opt in.

Overnight, the number of profiles available to law enforcement dropped from more than 1 million to zero. While the pool has grown slowly since then, as more people click a police-shield icon on GEDmatch allowing authorities to see their profile, cases remain more difficult to solve, investigators say.

CeCe Moore, a leading specialist in using DNA evidence and family trees to identify criminal suspects — a method known as investigative genetic genealogy — depends on GEDmatch for her work. After entering a suspect’s DNA profile into the site, she reviews the results and assesses the likelihood of law enforcement being able to determine the suspect’s identity. She then scores each case from 1 to 5, 1 being a sure thing and 5 a long shot.

“I’m giving a lot more fives than I used to,” said Moore, who helped solve dozens of cases using GEDmatch before the site changed its terms of service, including the 1987 killing of a young Canadian couple, the 1988 murder of an 8-year-old Indiana girl and the 1992 rape and strangulation of a Pennsylvania schoolteacher.

This sharp drop in the usefulness of a promising technology has sparked an effort by law enforcement authorities and researchers like Moore to convince the public to take action. These groups hope to persuade more Americans to obtain their DNA profiles from direct-to-consumer genetic testing companies ─ most of which have large databases but don’t allow law enforcement searches ─ and share them publicly, including with law enforcement, on databases like GEDmatch. One direct-to-consumer company, FamilyTreeDNA, allows law enforcement to search its database, but charges for it and limits results.

Some people are reluctant, worried that their DNA profiles will be hacked or used against their wishes, whether in the pursuit of a criminal or in the sale of data to health care companies. There are also concerns that DNA sharing will lead to the end of anonymity.

But law enforcement authorities and genetic sleuths who work with them argue that there is greater public good in helping to keep killers and rapists off the streets.

“In the interest of public safety, don’t you want to make it easy for people to be caught?” said Colleen Fitzpatrick, a genetic genealogist who co-founded the DNA Doe Project, which identifies unknown bodies, and runs IdentiFinders, which helps find suspects in old crimes. “Police really want to do their job. They’re not after you. They just want to make you safe.”

A ‘very valuable tool’

To illustrate those points, investigators tell the story of Angie Dodge.

Dodge, 18, was raped and murdered in 1996 in her Idaho Falls, Idaho, apartment. A year later, a man confessed to the crime, and although he later recanted and his DNA didn’t match that of semen left on Dodge’s body, he was convicted of participating in the killing and sentenced to life in prison.

Carol Dodge, Angie Dodge's mother. Monte LaOrange / The Idaho Post-Register via AP file

Dodge’s mother grew convinced that the prisoner, Christopher Tapp, was not her daughter’s killer. She pressed authorities to reopen the case. In 2017, Tapp was freed in a deal with prosecutors in which his conviction — of aiding and abetting the murder — remained.

Vera Tapp talks about her son, Christopher Tapp, in 2014. Monte LaOrange / The Idaho Post-Register via AP file

So did the question of who left their DNA at the crime scene.

Almost a year later, California authorities said they’d used genetic genealogy to catch the Golden State Killer.

The announcement generated a surge of interest in the technique, as genetic genealogists teamed up with private companies to sell their services to law enforcement. (Public crime labs are not equipped to do the kind of DNA analysis required, and police generally aren’t fluent in methods used to build family trees.) Parabon NanoLabs was the first, hiring Moore to run its genetic genealogy services. Idaho Falls police asked the company to try it.

Parabon submitted the Dodge suspect’s DNA profile into GEDmatch in May 2018, but the DNA was so degraded that, even with more than 1 million profiles to compare against, the connections were sparse. Moore decided that genetic genealogy wouldn’t work and declined to take up the case.

But Dodge’s mother, Carol, begged Moore to keep trying. Moore relented and examined the connections more closely. With help from her team of genetic genealogists, she explored a series of leads that didn’t pan out. They kept at it for months, eventually discovering a new branch of the suspect’s family tree ─ and a potential suspect.

Police followed that man, collecting a cigarette butt he discarded and using it to obtain his DNA. It matched the crime scene profile, and in May 2019 Brian Leigh Dripps confessed, police said. A few weeks later, Tapp was exonerated. Dripps is awaiting trial.

Moore chronicled that search at a recent gathering of genetic researchers, investigators, prosecutors and lab technicians in Palm Springs, California. If she had been working on the Dodge case after GEDmatch limited access to its database, she told attendees of the International Symposium on Human Identification, “this case would not have been able to be solved by genetic genealogy.”

Christopher Tapp hugs Carol Dodge after the Idaho Falls police announced the arrest of Brian Leigh Dripps for the 1996 murder of Carol's daughter Angie. Monte LaOrange / The Idaho Post-Register via AP file

She said she understood why GEDmatch’s owners made the decision, but the result was allowing some violent criminals to remain free for longer than they would have been with the full power of genetic genealogy. She pleaded with her audience to take DNA tests and upload their profiles into GEDmatch.

“We don’t want this very valuable tool to slip out of our hands,” Moore said.

A slowdown in solving cases

Curtis Rogers didn’t ask for this.

Rogers, 81, works in Florida as a court-appointed guardian for the elderly. He founded GEDmatch as a free public service in 2010 after being inspired by his own experience connecting with people who shared his last name. He partnered with a computer programmer who wrote software that made it easy for people to find relatives through certain shared pieces of genetic material. The site became popular among professional and amateur genealogists, and as direct-to-consumer genetic testing services grew, GEDmatch enabled people to compare their DNA profiles in a single place.

Rogers knew little of law enforcement’s interest in his website until the Golden State Killer announcement. The news upset Rogers and some members. But he eventually accepted the site’s role in solving violent crimes where other forensic techniques ─ including searches for matches in criminal DNA databases ─ had failed.

“I am not totally comfortable with GEDmatch being used to catch violent criminals but I doubt it would be possible to prevent it,” Rogers told NBC News last year. “I feel it is important to make sure all our users are educated to the possible uses of GEDmatch so they can make up their own minds.”

As law enforcement searches of his site surged, Rogers imposed a few restrictions. He allowed investigators to pursue leads on homicides and rapes, but not less serious crimes like assaults.

Then, late last year, police in Utah asked Rogers to use the site to investigate an attack on an elderly church organist, who was seriously hurt but survived. Rogers agreed, and police used GEDmatch to identify a 17-year-old suspect, who was arrested in April.

But that bending of Rogers’ own rules on how police could use GEDmatch triggered a backlash that led him to change the site’s terms of service. On May 18, all GEDmatch members were removed from law enforcement searches and offered a chance to opt in if they wanted to be included.

Ethicists said the decision ensured that users would be properly informed about how their profiles would be used.

“People using genetic genealogy databases for their own purposes never anticipated this kind of access to their genetic information or that information being used to identify people they’re related to,” said Amy McGuire, director of the Center for Medical Ethics and Health Policy at the Baylor College of Medicine.

There is “a genuine tension between wanting to protect consumers and be respectful of their wishes and recognizing that working with law enforcement provides a social benefit,” she said.

A Baylor College of Medicine survey last year found 91 percent of respondents favored law enforcement using consumer DNA databases to solve violent crimes, and 46 percent for nonviolent crimes.

But with fewer links from GEDmatch to examine, investigators now have to spend more time seeking connections that could lead them to a killer. That means chasing down more leads, or asking innocent distant relatives to submit their DNA for genetic testing in hopes that their profile will help fill out the family tree. That kind of “target testing” raises its own set of privacy concerns.

“You only need to look at the pace of press releases since the time of the Golden State Killer and see that there was virtually one every week, if not more, and the pace of those cases being solved has reduced itself,” said Anne Marie Schubert, the district attorney in Sacramento County, California, where she oversaw the Golden State Killer investigation.

The limited GEDmatch access ultimately means higher costs for law enforcement who turn for help to Parabon, which dominates the private market for such work, or FamilyTreeDNA, one of the earliest direct-to-consumer genetic testing companies.

It also means that more cases might remain unsolved.

“If I had a larger team, we would certainly try more cases,” Moore said. “But because agencies are paying Parabon, we don’t want them to waste valuable resources or give false hopes.”

Rogers says he has done the right thing ─ for his members, and for the field he loves.

“We are here for genealogists, not for law enforcement,” he said. “On the other hand, law enforcement is here to stay. I feel a big obligation to make sure it’s used properly. I don’t want some half-cocked law enforcement person to do something that creates a story and ruins everything for everyone.”

Rogers has sent emails to members urging them to allow law enforcement to search their profiles, linking to a video message from a relative of one of the Golden State Killer’s victims.

“Many of these families have suffered for decades. They need your support,” he wrote in an email to members. “We hope you will encourage others who have been genealogically DNA tested to also add their information. We believe it is the caring thing to do.”

So far, Rogers said, 181,000 members have opted in. That’s far from the critical mass of 1 million that some researchers say is needed to solve cold cases with regularity. It could be many months, and perhaps years, before GEDmatch’s law enforcement-accessible database reaches that size.

“I’m sorry we had to do this. However, I feel very strongly that when we bit the bullet and did what we did, we set the whole future on a much stronger base,” Rogers said of genealogy. “Two or three years from now, this whole thing will be forgotten.”