Seattle police said Tuesday they have solved a murder from nearly 52 years ago with the help of DNA and a family tree — a method that has revolutionized cold-case investigations across the U.S. in the past year.

Susan Galvin was a 20-year-old records clerk for the department in July 1967 when she was found raped and strangled in a parking garage elevator at Seattle Center. Dozens of people were questioned, and one potential suspect — a professional clown who had been seen with her a few days earlier, and who quit his job just a few days later — was never charged for lack of evidence. The clown, located in Utah in 2016, was finally cleared by a DNA test.

Last summer, Seattle police provided the killer's DNA to Parabon NanoLabs in Reston, Virginia. CeCe Moore, a Parabon genealogist who is known for her work on the public television series "Finding Your Roots," used the public genealogy database GEDmatch to create a family tree for the killer and ultimately identified a potential suspect as Frank Wypych, a married Seattle man and former soldier who died of complications from diabetes in 1987.

Seattle police exhumed his remains from a cemetery earlier this year to collect DNA and confirmed it matched that extracted from Galvin's clothing in 2002. Investigators are now looking into whether he may have killed anyone else while stationed in New York, Alaska and Germany while in the Army.

"It's the oldest case where genetic genealogy has helped to identify the suspect," Moore said Tuesday. "It's amazing the DNA was still viable. The original investigators who collected the crime scene evidence did such a great job, long before they could even have imagined what could be done with DNA."

Public genealogy databases, which contain information from people who have obtained their DNA profiles from companies like 23andMe and Ancestry.com, have become a powerful police tool in the past year, since investigators in California revealed that they used the method to identify and arrest Golden State Killer suspect Joseph DeAngelo. DeAngelo, a former police officer, is accused of having murdered at least a dozen people and raped 50 in the 1970s and '80s.

More than 60 cases have been solved with genetic genealogy since then, including five in Washington state — three in the past month. At least two other cases have been solved just this week: San Diego police announced Monday that the FBI's forensic genetic genealogy team helped them identify and arrest a serial rapist whose crimes date back to 1994, and police in Terre Haute, Indiana, said they solved the killing of a 19-year-old woman on the campus of Indiana State University in 1972. Like Wypych, that suspect is long dead; he was shot by a deputy who saw him trying to abduct a woman in 1978.

Privacy advocates, including the American Civil Liberties Union, have expressed concern over the use of public DNA databases in police investigations. They argue that by posting DNA profiles to public sites, people are also posting information about close and even distant relatives, with potentially serious implications for privacy rights.

Moore said when she ran the suspect's DNA, she came up with two distant cousins — people who shared less than about 2% of the killer's DNA — and a handful of people who were even more scarcely related. She saw surname patterns suggesting Polish ancestry, and the suspect's DNA profile was predicted to be about 16% Native American.

She worked her way backward using those clues, and eventually found a couple — a man born in 1828 in Kentucky and a woman born Missouri in 1837 — from whom both of the distant cousins were descended. She then followed the generations forward from that ancestral couple, and found Frank Wypych, who was born in Seattle and would have been 26 at the time of the killing.

Galvin had left her childhood home in Spokane a year before she was killed, according to a statement from one of her brothers, Lorimer "Larry" Galvin, who now lives in Florida. He thanked Detective Rolf Norton, who began reinvestigating the case in 2016.

"52 years later we learn the who, but still have no clear understanding as to the why," Galvin wrote. "There will always be that lingering question.

Wypych was married and the father of a young child, with a second child born two years later, police said. He and his wife divorced in 1971, and he was convicted of larceny that year — his only criminal conviction. He served nine months in jail and was arrested for a weapons offense in Seattle in 1975.

The department said it no longer had records of that offense, but relatives told investigators he had been impersonating a police officer and making traffic stops in uniform, armed with a gun. Wypych's children cooperated with the investigation, though they were stunned to learn about the killing, Norton said.

Norton said none of the original detectives on the case remain alive.

"It's really a credit to everyone involved back then," Norton said. "They processed that case like it was 2015."