SACRAMENTO, Calif. >> The genealogy website used to find the man accused of being California’s Golden State Killer had no idea its database was tapped in pursuit of a suspect who eluded law enforcement for four decades, the site’s co-founder said today.

The revelation came as former police officer Joseph DeAngelo made his first court appearance. Handcuffed to a wheelchair in orange jail scrubs, he looked dazed and spoke in a faint voice to acknowledge he was represented by a public defender. He did not enter a plea.

Authorities never approached Florida-based GEDmatch about the investigation that led to DeAngelo, and co-founder Curtis Rogers said law enforcement’s use of the site raised privacy concerns that were echoed by civil liberties groups.

The free genealogy website, which pools DNA profiles that people upload and share publicly to find relatives, said it has always informed users its database can be used for other purposes. But Rogers said the company does not “hand out data.”

“This was done without our knowledge, and it’s been overwhelming,” he told The Associated Press.

For the team of investigators tracking the attacker suspected of killing 13 people and raping nearly 50 women during the 1970s and ’80s, GEDmatch was one of the best tools, lead investigator Paul Holes told the Mercury News in San Jose.

Officials did not need a court order to access GEDMatch’s large database of genetic blueprints, Holes said. Major commercial DNA companies say they do not give law enforcement access to their genetic data without a court order.

DeAngelo, 72, was arrested Tuesday after investigators matched crime-scene DNA with genetic material stored online by a distant relative. From there, they narrowed the search down to the Sacramento-area grandfather using DNA obtained from an item he discarded, Sacramento County District Attorney Anne Marie Schubert said.

Civil libertarians said the practice raises legal and privacy concerns for the millions of people who submit their DNA to such sites to discover their heritage.

There are not strong privacy laws to keep police from accessing ancestry site databases, said Steve Mercer, the chief attorney for the forensic division of the Maryland Office of the Public Defender.

“People who submit DNA for ancestors testing are unwittingly becoming genetic informants on their innocent family,” Mercer said, adding that they “have fewer privacy protections than convicted offenders whose DNA is contained in regulated databanks.”

While people may not realize police can use public genealogy websites to solve crimes, it is probably legal, said Erin Murphy, a DNA expert and professor at New York University School of Law.

“It seems crazy to say a police officer investigating a very serious crime can’t do something your cousin can do on a Tuesday,” Murphy said. “If an ordinary person can do this, why can’t a cop? On the other hand, if an ordinary person had done this, we might think they shouldn’t.”

While most consumers would have to get a genetic profile from a commercial company such as Ancestry.com and 23andMe, the police may have obtained the DNA profile in their crime lab before uploading it to GEDmatch, she said.

DNA was just coming into use as a criminal investigative tool in 1986 when the predator also known as the East Area Rapist apparently ended his decade-long wave of attacks.

As a former police officer, DeAngelo probably would have known about the new method, experts said.

Police at the time suspected they were chasing a fellow cop or armed services member because he was so methodical and meticulous, said Wendell Phillips, a former Sacramento deputy who joined the hunt for the rapist who terrorized the suburbs east of the state capital.

In fact, officers assigned to a special task force were required to submit saliva samples to exclude anyone who shared a genetic trait, Phillips said. About 85 percent of people secrete their blood type in saliva and body fluids, but the rape suspect was in the roughly 15 percent who didn’t.

“Obviously, you didn’t want the East Area Rapist on the team,” Phillips said. “That turned out to be a pretty good concern.”

No one who knew DeAngelo over the decades connected him with the string of crimes throughout California from 1976 to 1986.

DeAngelo worked nearly three decades in a Sacramento-area supermarket warehouse as a truck mechanic, retiring last year. He was known by neighbors in suburban Citrus Heights for keeping his lawn manicured and cussing loudly.

Investigators are removing virtually everything from DeAngelo’s home in search of mementos such as class rings, earrings and photos taken from crime scenes as well as weapons, Jones said.

DeAngelo, who has been charged with eight counts of murder, is on suicide watch in the psychiatric ward of the county jail and has been muttering to himself, said Sacramento County Sheriff Scott Jones. Authorities said more charges are likely to be filed later.

Police in the central California city of Visalia said Thursday that DeAngelo is now a suspect in a 13th killing and about 100 burglaries that occurred while he was a police officer in the neighboring farm town of Exeter from 1973 to 1976.

In 1975, community college teacher Claude Snelling was shot while trying to stop a masked intruder from kidnapping his 16-year-old daughter from his home.