April 27 (UPI) -- The man police believe is the notorious Golden State Killer was finally identified after investigators used genealogy websites to match DNA left at one of the crime scenes, authorities said.
Joseph James DeAngelo will be arraigned Friday, three days after he was arrested and charged with the 1978 killings of Katie and Brian Maggiore -- victims police had long attributed to the Golden State Killer, also called the East Area Rapist.
DeAngelo, now 72, is believed have killed at least 12 people and committed 45 rapes between 1976 and 1986 in the Sacramento, Central Valley and Southern California regions. He's also suspected of burglarizing hundreds of homes.
Investigators said they finally tracked him down by matching known DNA of the killer through genealogy websites. When genetic markers from one of the crime scenes was plugged into the sites, investigators say they located DeAngelo's family members and narrowed their search to him.
DeAngelo was an officer with the Auburn Police Department for three years in the 1970s, and also worked for police near Visalia, Calif., where investigators say he may be connected to additional crimes in the mid-1970s.
DeAngelo was divorced and living with his daughter and granddaughter at the time of his arrest Tuesday. Relatives said they were shocked to learn he may be involved in the crime spree that stretched for a decade.
His sister told The Sacramento Bee he never displayed "any kind of madness," and said her family is haunted by thoughts of the victims.
"It's hard to believe," Rebecca Thompson said. "We're saddened and all kinds of things. We're sorry for the victims without any doubt. It's really hard to think about all the victims.
"I just can't believe it."
Officers said they'd kept DeAngelo under surveillance for almost a week before making the arrest outside his Sacramento area home.
"He was very surprised," Sacramento County Sheriff Scott Jones said. "It happened almost instantaneously."