A Northern California man suspected of sexually assaulting two women decades ago is now facing charges after detectives recovered his DNA from a discarded Baskin-Robbins spoon and found it matched the crime scenes, officials said.
In May 1997, a woman was walking to a Union City public transit station after work when a man dragged her to a secluded area, cut her clothes off with a knife and sexually assaulted her, according to prosecutors and court documents. The suspect’s DNA was found on the victim's clothes, prosecutors said.
In September 1997, another woman was attacked while walking by Livermore High School, prosecutors said. The suspect pulled her from the bleachers, held her to the ground and sexually assaulted her, according to the probable cause document.
DNA was also found at that crime scene and was found to be a match to the suspect in the first attack, prosecutors said.
The samples were uploaded to the national law enforcement database CODIS, but no match was found, prosecutors.
Over 20 years went by without answers.
Until the suspect -- 60-year-old Gregory Paul Vien, a longtime Livermore resident -- was identified this year through the novel investigative tool of genetic genealogy, Alameda County District Attorney's Office said in a statement on Monday.
Genetic genealogy compares unknown DNA evidence from a crime scene to public genetic databases to identify suspects through their family members, who voluntarily uploaded their DNA to those databases. As law enforcement agencies across the country ramp up the use of genetic genealogy, some are concerned the tool is an invasion of privacy to those who voluntarily submit their DNA to genealogy databases for family ancestry purposes.
Genetic genealogy has been called a "game-changer" in the effort to crack cold cases. Since the arrest of the suspected "Golden State Killer" in April 2018, about 100 suspects have been identified through the technology, according to genealogy expert CeCe Moore. Just last week, the suspected Potomac River Rapist, who "terrorized" women in the Washington, D.C., area in the 1990s, was caught with genetic genealogy.
Once Vien was identified as a potential suspect through genetic genealogy, detectives surveilled him and collected a Baskin-Robbins spoon he had discarded, according to the probable cause document.
The spoon was sent for analysis and the DNA on it was found to be a match to the sex assaults, court documents said.
It was not immediately clear if he had an attorney.