By Emmett Berg
SAN FRANCISCO (Reuters) - The remains of two teenage girls missing since the 1980s have been identified among bones found in an abandoned well in California that a convicted serial killer said he and a partner-in-crime used as a burial site, authorities said on Friday.
Forensic examinations and DNA testing determined that two of three possible skeletons found in the sealed well 100 miles east of San Francisco belong to Kimberly Billy and Joann Hobson, San Joaquin County Sheriff Steve Moore said.
Moore said efforts were still underway to identify additional skeletal remains that may belong to another victim of the "Speed Freak Killers," named for the methamphetamine-fueled violence they were found to have committed.
Authorities have recovered nearly 1,000 human bone fragments, along with a woman's ring, a purse, shoes and some coats from the 50-foot well, located near a former cattle ranch in the community of Linden that was known as weekend gathering spot for local teenagers.
Investigators were directed to the well and four other burial sites by a map serial killer Wesley Shermantine gave a Sacramento bounty hunter, Leonard Padilla, who agreed to pay the convicted killer $33,000 for information leading to the location of his victims' bodies.
Shermantine was convicted in May 2001 of four murders dating back to 1984 and is currently on California's death row.
Prosecutors have previously said they believed Shermantine and his co-defendant, Loren Herzog, a childhood friend who was convicted of three murders, were linked to as many as two dozen killings.
Herzog's murder conviction was ultimately reduced to a single count of manslaughter on appeal, and he was released on parole after 14 years in prison. He committed suicide in January.
Of the teenagers whose remains were recently identified, 19-year-old Billy had reported missing by her grandmother in December 1984. Hobson, 16, was reported missing by her mother the following September. Shermantine and Herzog were never charged in their disappearances.
Besides the skeletal remains retrieved from the well in Linden, remains unearthed from two separate, single graves miles away near San Andreas in Calaveras County have been identified as belonging to known "Speed Freak" victims Cyndi Vanderheiden, 25, who disappeared in 1998, and Chevelle Wheeler, 16, missing since 1985.
Authorities said that once they finish combing through the Linden well, they will turn their attention to two more sites mapped by Shermantine.
(Writing and additional reporting by Dan Whitcomb; Editing by Cynthia Johnston)