SAN ANDREAS (CBS13) – A human skull was discovered by deputies searching a rural property in San Andreas, according to John Vanderheiden, whose daughter was murdered by the “Speed Freak Killers.”

During an interview with CBS13 on Thursday morning, Vanderheiden received a call from the San Joaquin Sheriff’s Department saying a skull had been found. Vanderheiden says he’s waited 14 years for that call, and believes the remains could be that of his daughter, Cyndi.

“We hope it’s her so we can finally bring her home,” Vanderheiden said. “If it’s not, then it’s another of their victims.”

Sheriff’s deputies from San Joaquin and Calaveras counties searched the property Wednesday and resumed on Thursday before the skull was found about 11 a.m. San Joaquin sheriff’s spokesman Deputy Les Garcia said the Department of Justice had been called in to do DNA testing. He also said another bone was found near the skull but couldn’t confirm if that was human. Garcia said Santa Clara County sheriff’s search dogs were instrumental in Thursday’s discovery.

Cyndi is one of the victims of Wesley Shermantine and Lorez Herzog, who were dubbed the “Speed Freak Killers” during their murder trial in 2001. The two longtime friends went on a killing spree in the 1980s and ’90s fueled by drug use. She went missing from her Clements home in 1998. She was 25 at the time of her disappearance.

Shermantine and Herzog were convicted of killing four people, but Shermantine says there are more victims and has been corresponding from death row with local bounty hunter Leonard Padilla about the location of remains. Herzog, who was out on parole, committed suicide last month.

Garcia didn’t credit Shermantine much with Thursday’s discovery, but Padilla said it wouldn’t have been possible without maps he provided of the property, which used to belong to his parents.

Padilla said Shermantine sketched the map in his San Quentin cell after the two spoke on the phone last week. Shermantine wanted assurances that the bounty hunter still intended to pay him $18,000 if he disclosed the location of Vanderheiden’s resting place, Padilla said.

Padilla made the offer three weeks ago. But a planned search led by the California Department of Corrections and Rehabilitation was called off after San Joaquin County Sheriff Steve Moore objected to being left out of the loop. Moore said he was concerned with safety issues.

Authorities feared Shermantine would stop cooperating because of the delay. But after Padilla guaranteed him his offer was still good, Shermantine drew a detailed map that ended up leading searchers to the human remains.

Check back at cbssacramento.com or watch the CBS13 newscast at 5 p.m. for the exclusive interview with John Vanderheiden when he took the phone call from the sheriff’s office.

(The Associated Press contributed to this story.)