For 22 years, police in Livermore and Union City hoped to identify a man who brutally sexually assaulted two women as they walked along the street.

Investigators collected DNA evidence at the time, but for more than two decades the assailant remained unidentified, his victims wondering if they would ever feel safe.

This week, however, police and prosecutors announced that scientific technology, including a common public DNA database and saliva from a Baskin-Robbins plastic spoon, helped them identify the alleged attacker. Gregory Paul Vien, a 60-year-old Livermore handyman with a wife and children, was arrested Nov. 5 and charged with the crimes.

“He was shocked,” Livermore police Sgt. Steve Goard said. “To all criminals: We will find you.”

Vien, who declined to talk to investigators, is charged with offenses that could send him to prison for the rest of his life. At a Nov. 7 court hearing, he pleaded not guilty to a string of sexual assault charges and special allegations including kidnapping, use of a deadly weapon and having multiple victims. He was scheduled to make an appearance Wednesday (Nov. 20) at the East County Hall of Justice in Dublin.

The allegations stem from May 6, 1997, when a 41-year-old woman walking home from a Union City BART station was attacked on the street, dragged into a secluded area of a nearby field, and sexually assaulted by a man who cut off her clothes with a knife. The victim described the man as 6 foot 3 inches tall, 240 pounds, wearing a hooded jacket and gloves, a county court document said.

Police collected the assailant’s biological fluid from the inside of the victim’s jacket and uploaded it into a DNA database, hoping for a match.

Four months later, a 22-year-old woman on an evening walk at Livermore High School was attacked. Again, police collected DNA evidence and uploaded it into the system. Although they did not obtain an identification, the DNA matched that was taken from the Union City crime, police said.

Despite periodic checks by law enforcement over the years, no one in the state’s prison system matched the DNA until July when a public database,, a site similar to, identified a familial link to one of Vien’s distant relatives who had used the site. An authorization gave law enforcement the right to investigate the match, Goard said.

Detectives immediately looked into Vien’s family, finding that he still lived in the same Livermore home as in the 1990s, three miles from the second crime scene.

Investigators put Vien under surveillance, watching him as he moved about the city. According to a court document, Vien stopped for ice cream at a Baskin-Robbins. After he walked away, detectives moved in and collected the plastic spoon. DNA from the spoon matched DNA from the Livermore victim’s jacket.

Vien had been arrested over the years for drug offenses, but nothing serious enough to warrant submitting his DNA to the system, Goard said.

Vien’s arrest stunned his family, which discovered he allegedly lived “an alternative life,” Goard said.

Goard described the two victims as “very relieved.”

“One described it as ‘living in 22 years of fear not knowing where my attacker was,’” Goard said. “Now they know he has been apprehended and is behind bars.”

Investigators also were relieved, excited that they could solve a crime from so many years ago.

Detectives believe Vien might be a suspect in three more unsolved similar sexual assaults that occurred in Livermore from 1995 to 1997. Officers would not release his photograph while the crimes are under investigation, Goard said.

The crimes appeared to stop after that. Vien was known to frequent Union City, Fremont, Hayward, San Lorenzo and San Ramon in the mid to late 1990s.

Police asked anyone with information about the sexual assaults or any other suspicious activity involving Vien to contact Livermore detectives at 925-371-4790.