LAKE WORTH, FLA. — On Halloween night in 1996, a man in a skeleton mask knocked on the door of a house in Martinez, Calif., handcuffed the woman who greeted him and raped her. Two weeks later, he called the dental office where she worked. Investigators tried to track him down through phone records, but got nowhere. They obtained traces of his semen, but there was no match for his DNA in any criminal database.
Last month — two decades after the crime — the Sacramento district attorney’s office tried something new to finally crack the case of this serial rapist, who had attacked at least 10 women in their homes. Investigators converted the assailant’s DNA to the kind of profile that family history websites such as 23andMe are built on, and uploaded it to GEDmatch.com, a free site open to all and beloved by genealogical researchers seeking to find biological relatives or to construct elaborate family trees.
Within five minutes of reviewing the results, the investigators had located a close relative among the million or so profiles in the database. Within two hours, they had a suspect, who was soon arrested: Roy Charles Waller, a safety specialist at the University of California, Berkeley.
The arrest marked the 15th time that GEDmatch had provided essential clues leading to a suspect in a murder or sexual assault case, starting with the arrest in April of Joseph James DeAngelo, a former police officer, for the rapes and murders committed across California in the 1970s and 1980s by the notorious Golden State Killer.
And no one has been more surprised than the two creators of GEDmatch — Curtis Rogers, 80, a retired businessman who could be easily mistaken for just another low-key Florida grandpa in his white Velcro sneakers, and John Olson, 67, a transportation engineer from Texas. Their tiny outfit, which began as a side project, has unintentionally upended how investigators across the country are trying to solve the coldest of cold cases.
Within three years, the DNA of nearly every American of Northern European descent — the primary users of the site — will be identifiable through cousins in GEDmatch’s database, according to a study published on Thursday in the journal Science.
“It’s kind of been a shock to all of us how these things developed,” said Mr. Rogers, who was drawn to genealogical research by a search for his own family history. “All of a sudden, all this notoriety.”
Mr. Olson agreed: “I feel like I’m on a high-speed ride with no way to steer.”
Since Mr. DeAngelo’s arrest, law enforcement agencies stretching from Washington State to Florida have turned to the site to crack decades-old cold cases. Increasingly, it’s being used in recent cases as well.
Initially, Mr. Rogers was outraged at how law enforcement was using his website, but he now feels proud.
“Within a year I think it will be accepted,” he said. Some genealogists find that notion profoundly problematic, given the many ethical and privacy issues that have emerged as investigators have come to rely on a privately owned family history site to solve crimes.
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A visit to headquarters
GEDmatch headquarters, in Lake Worth, Fla., is a small yellow house with turquoise shutters, a white picket fence and a palm tree in the yard. A brief tour, the first that Mr. Rogers had ever given a journalist, began with his desk, the only desk in the house. He drives there every day from his home half an hour away.
Mr. Olson, his business partner, works out of his home in Texas. Three retired computer scientists sometimes help remotely. There are no other employees, but there is a fluffy white cat.
Past the bathroom is a room filled with Mr. Rogers’ wife’s paintings and labeled boxes, evidence of his other job as a professional guardian.
The GEDmatch database can now be used to identify at least 60 percent of all Americans of European ancestry through their cousins, according to two recent analyses by genetics researchers. But unlike 23andMe and other big genealogy sites, GEDmatch has no lab. Rather, the site serves as a place where people, who have had their DNA analyzed elsewhere, can locate more relatives and dive deeper into their ancestry.
Some GEDmatch users are family tree completists who collect cousins the way some people collect baseball cards. Other users are retirees digging into old family mysteries. Many others are adoptees and the genealogists who help them use the site’s tools to track down biological parents. More than 10,000 people likely have used the site in this manner over the past eight years, according to two genealogists who teach people how to conduct such searches.
Aesthetically, GEDmatch.com resembles an internal company wiki in need of an update. But what it offers to researchers and criminal investigators is tremendous flexibility. There are now more than 17 million DNA profiles in genealogical databases, but most of the bigger sites restrict what can be uploaded, banning not only crime scene evidence but anything processed by an external lab. GEDmatch will take it all — blood processed by an obscure lab, spit processed by 23andMe — for free, so long as it’s in the right format.
The site is also useful for people building an extensive family history. The average person can find any number of cousins on existing genealogy sites. But the key, for a genetic sleuth, is figuring out precisely how those cousins are related to a person of interest, and to each other. The tools that Mr. Olson created — primarily because he found the math intriguing — enable users to see the precise genetic segments where cousins overlap. From the site’s one million or so profiles, a skilled genetic detective can often puzzle out an individual’s identity from a single third cousin match.
“There’s nothing else like it,” said Barbara Rae-Venter, a genetic genealogist who used the site to help crack the Golden State Killer case.
Using GEDmatch in this way is not easy. Most investigators who upload crime scene evidence to the site still require the help of a highly skilled genetic genealogist such as Dr. Rae-Venter. The DNA is just the first clue; from there, the family tree must be filled in using other kinds of data, including social media profiles and birth records. Still, for those who know what they are doing, it’s sometimes possible to identify a murder suspect or find an adoptee’s biological parent in less than two days.
All of this is hard to fathom while watching Mr. Rogers “zap” customer service emails on his worn Toshiba laptop.
“I take off one day, I’d never catch up,” he said, settling his sneakers on the base of his faux-leather swivel chair.
He sent a 15-step guide to a user having trouble uploading a file, one of many basic tech support emails he responds to daily. Other common questions include: does this mean my father isn’t actually my father?
On his desk was a short stack of $10 checks — the monthly amount Mr. Rogers charges for “Tier 1 membership” to the site, which technically is free to use. So far, GEDmatch has 6,500 or so members, enough to cover basic expenses and pay its founders a little something.
Mr. Rogers spent his early career in business, growing an international consumer base for brands such as Hellmann’s mayonnaise and Quaker Oats. He knows he could charge more. But that wouldn’t feel right, he said, because the goal of family history research is to help people, a sentiment common among dedicated genealogists.
This goes back to the pilgrims
Mr. Rogers grew up hearing that he was related to Thomas Rogers, who came over on the Mayflower in 1620. His dive into genealogy began when he decided to investigate it.
As it happened, there was no relation. But from there Mr. Rogers fell down a family history rabbit hole. Soon he was running an online genealogy project for people who shared his surname, and looking for a computer coder to make it easier to map out distant relations.
Another Rogers in the family-tree project introduced him to Mr. Olson, who was happy to help out the enthusiastic Mr. Rogers. Plus, Mr. Rogers’ coding requests were easy for an engineer accustomed to solving complex traffic-signal puzzles.
The pair worked well together, and in 2010 they decided to move beyond the Rogers name. They launched GEDmatch.com, a reference to a GEDcom, a type of family tree file used by genealogists, and an abbreviation for genealogical data communication.
Around this time, a number of genealogy companies had begun offering autosomal DNA testing, a type of genetic analysis useful for finding relatives.
Mr. Rogers asked Mr. Olson whether he could do something with all the data.
“I think it was a challenge for him and then he kind of got hooked,” said Mr. Rogers.
Before long, and with no advertising, they said, their database was doubling in size every year.
What convinced Mr. Rogers to keep investing in the site were “love letters for GEDmatch,” which were unlike any customer service notes he’d seen, and “people really like Hellman’s mayonnaise.”
Mr. Rogers’ ethical quandary
On April 25, the Sacramento County district attorney’s office announced that there had been a breakthrough in the case of the Golden State Killer.
Mr. Rogers saw the news while sitting in bed watching TV.
“I’d never even heard of the Golden State Killer before they captured this guy,” he said.
But when one of the newscasters mentioned “a new form of DNA technology,” he turned to his wife and asked, “Do you suppose I was involved?”
It seemed possible; around six months earlier, two companies involved in criminal investigations had asked for his blessing to use the site.
Law enforcement agencies have their own database for criminal investigations: Codis, which contains more than 16 million DNA profiles. But forensic profiles contain only a tiny fraction of the hundreds of thousands of genetic markers that genealogy sites rely on. If investigators are unable to find an exact match there, a site such as GEDmatch is better for tracking down suspects through their relatives.
The site’s privacy agreement had always been vague, essentially stating that its owners had no control over how any individual’s genetic or family tree data would be used. But explicitly sanctioning a law enforcement presence felt different.
“There’s probably no way I could stop you,” he said he told Parabon, a forensic consulting firm, and the DNA Doe Project, an organization focused on identifying bodies. “But we can’t give you permission. I have to protect the site.”
Why Mr. Rogers changed his mind
Mr. Rogers was furious when he confirmed that a third set of investigators, without first telling him, had involved GEDmatch in the Golden State Killer case. It seemed inevitable that the news would drive thousands of people off the site.
While giving his house tour, Mr. Rogers handed over a stack of emails from that first week. On top, an expletive-filled note accused him of violating users’ privacy. But underneath it was email after email of congratulations, including one woman’s request to make sure that her profile would be easy for criminal investigators to find. She suspected that her father, who had been in and out of mental institutions after killing her grandfather, had taken other lives.
Mr. Rogers and Mr. Olson hadn’t expected such an outpouring of support. Neither did they anticipate 5,000 new uploads to the site shortly after Mr. DeAngelo’s arrest — a daily record, Mr. Olson said.
Two weeks later, Parabon announced that it was joining forces with CeCe Moore, a genetic genealogist, to use GEDmatch to solve crimes.
“This simply would not be possible without the courage of John and Curtis to allow law enforcement to use this database,” said Ms. Moore, who has helped identify more than a dozen suspects in murder and sexual assault cases using the site in the past five months.
As praise has flowed in, both men began to relax. By May, they had tweaked the privacy agreement to explicitly mention that users’ profiles might be used in a homicide or sexual assault investigation. By September, any lingering doubts they had were gone.
“I have absolutely no concerns that a person’s privacy is violated, because there are so many people whose DNA helped get to a capture,” Mr. Rogers said.
But many observers disagree. When any one person’s DNA can lead investigators to hundreds of a suspect’s relatives, the standard model of individual consent does not hold up, said Rori Rohlfs, a professor at San Francisco State University who has studied familial searches. She finds it ironic that police in California must get approval from a judge to search criminal databases for a murder suspect’s brother, but can upload DNA to GEDmatch to identify cousins without any restrictions.
The excitement around cases that have not yet gone to trial also risks reinforcing the notion that a DNA match is proof of guilt, some researchers warn.
Recent developments have led numerous African-American customers to quit the site out of concern that criminal investigators might abuse the data, several genealogists said.
“Because so many African-Americans have been falsely accused, and because genetic testing is not a perfect science, law enforcement should not be allowed to use GEDmatch,” said Tony Burroughs, the former president of the Afro-American Genealogical and Historical Society of Chicago.
The exit of those users is particularly tragic, said Teresa Vega, a family historian, because the site had been one of the best tools for connecting families separated by slavery.
As more law enforcement agencies have begun experimenting with genetic genealogy, the GEDmatch database has grown by about 1,800 profiles every day, Mr. Olson said.
“I don’t like it, I don’t like it one bit,” said Mr. Rogers’ wife, Janet Siegel Rogers, an artist. It was happy hour, and the tour had moved to her studio.
“What don’t you like?” Mr. Rogers asked.
As it turned out, she didn’t like her husband’s email habits.
“He’s at it 24-7,” she lamented.
As she spoke, Mr. Rogers took a sip of wine.
From the trace of saliva he left on the glass, a skilled genetic genealogist could use the website he created to reveal his name and a dozen close relatives. It would also be possible to determine that while he is not related to any pilgrims, he is in fact the descendant of Vikings.
Heather Murphy is a science reporter. She writes about the intersection of technology and our genes and how bio-tech innovations affect the way we live. @heathertal