Authorities in Santa Clara County arrested a suspect this week in the 1973 killing of 21-year-old Leslie Perlov in Palo Alto — the latest Bay Area cold case to be cracked by investigators submitting a suspect’s DNA to a public genealogical website, officials said Wednesday.

The arrest of 74-year-old Hayward resident John Arthur Getreu follows the sensational capture of Golden State Killer suspect Joseph James DeAngelo this year outside of Sacramento, and the September arrest of accused NorCal Rapist Roy Charles Waller.

In all three unrelated cases, investigators took DNA collected at crime scenes and plugged it into an open-source genealogical website GEDmatch. This work alone doesn’t necessarily identify a suspect, but it can generate a pool of a suspect’s possible relatives and new leads for investigators.

Getreu was arrested Tuesday at his home in Hayward and booked in Santa Clara County Jail where he’s being held without bail in Perlov’s killing.

Perlov, a Stanford graduate and law clerk, was last seen at her Palo Alto workplace around 3 p.m. on Feb. 13, 1973. The same day, authorities found her orange 1972 Chevy Nova at a gate of an old quarry near Old Page Mill Road and Page Mill Road, to the south of Stanford University’s campus.

Three days later, deputies on horseback found Perlov’s body under an oak tree in the foothills west of Stanford. The county medical examiner ruled her death a homicide. She had been strangled and her pantyhose were stuffed into her mouth.

The killing went unsolved and evidence remained shelved for decades until cold case investigators with the Santa Clara County Sheriff’s Office recently took another look at the case. They submitted evidence to the county crime lab where criminalists found a DNA profile of an unknown man.

In July, investigators called on Virginia-based DNA technology company Parabon NanoLabs, which contracts with law enforcement agencies around the country. When a DNA profile fails to match on a national database, agencies have begun using companies like Parabon for a more advanced investigation to find the unknown suspect’s relatives.

“Parabon submitted a genetic data profile created from the unknown crime scene DNA sample to a public genetic genealogy database for comparison in hopes of finding individuals who share significant amounts of DNA with the unknown subject,” the Sheriff’s Office said in a press release.

Genetic matches helped investigators narrow down a list of possible suspects, and they ultimately identified Getreu after acquiring his DNA.

Officials did not say how they obtained his DNA. Investigators often collect a suspect’s discarded items, like a tissue, to get their genetic material.

The crime lab matched Getreu’s DNA to the suspected killer’s on Nov. 9, officials said, noting that the chance of the DNA belonging to another person is around 1 in 65 septillion, or 65 followed by 24 zeros.

Investigators in dozens of cases have been looking anew at old cases, following the ingenious work in the Golden State Killer case.

In that case, investigators used GEDmatch, a free, open-source website that lets users compare DNA samples to help family members connect. Parabon NanoLabs also plugs suspects’ DNA into the database.

GEDmatch has said it does not work with law enforcement, but the company’s terms of service state that submitted DNA could be used for a variety of purposes.

Getreu was born in Ohio and was arrested in 1963 in Germany for sexually assaulting and strangling the 16-year-old daughter of a U.S. Army chaplain, according to an Associated Press story from the time. Getreu, who was 18, was in Germany with his father — a sergeant major in the Army.

Getreu was considered a juvenile and faced a maximum of 10 years in jail for the killing. It was not immediately clear how the case was resolved.

Investigators are working with other jurisdictions to determine if Gatreu is connected to other unsolved crimes.

Evan Sernoffsky is a San Francisco Chronicle staff writer. Email: esernoffsky@sfchronicle.com Twitter: @EvanSernoffsky