More than 300 human bones have been found in a Linden, Calif., mine where "Speed Freak" serial killers Wesley Shermantine and Loren Herzog buried victims of their drug-fueled killing spree.
Shermantine, who is on death row, provided a hand-drawn map to San Joaquin sheriff's officers to help them locate the burial ground for as many as 10 or more victims from the spree, which occurred during the 1980s and 1990s.
Herzog, when he was told about Shermantine's cooperation with investigators, killed himself last month.
Today marked the fourth day of searching and sifting through dirt from the mine, which police excavated in batches and then combed through for evidence. In addition to bones, investigators have found clothing, shoes, jewelry, and other personal effects.
According to Sacramento County Sheriff's Department spokesman Les Garcia, investigators combed through 12 piles of dirt on Saturday, and 35 piles of dirt Sunday. The search resumed today.
Nearly two dozen searchers and specially trained dogs have helped find the remains since Thursday, when the digging began. Many of the items have been found more than 45 feet deep in the ground, Garcia told ABC News affiliate KXTV.
"It's tedious," Garcia said. "They're going through and finding minute bones and items," said Garcia.
Among the bones and apparel, searchers found a ring with initials on it, which they hope will help identify one of the killers' victims.
"We believe the jewelry is going to help us. I believe some engraving. It's been buried for several years," said Garcia. "It's going to be a lengthy process. So, we're continuing our efforts."
Police believe that at least two victims have already been identified. One, Chevelle "Chevy" Wheeler, a 16-year-old girl, is believed to have been killed by the pair three decades ago.
San Joaquin Sherriff Steve Moore called the Wheeler residence in Crossville, Tenn., Friday morning, to inform them that a skull and other human remains, along with clothes matching the description of what Chevy Wheeler was last seen wearing, had been found.
"Police said they had a diagram from the guy that killed my daughter and they went out and did some digging," said Raymond Wheeler, Chevy's father. "I just can't believe that devil decided to speak out over 20 years later."
Another woman, Cyndi Vanderhein, was 25 when she was last seen in front of her home in Linden in 1998.
"Thursday we found a first set of remains, and after preliminary tests conducted on a partial skull we're led to believe they may be that of Cyndi Vanderheiden," Garcia said.
Garcia said Vanderheiden's family members were contacted and were informed that these were just preliminary findings. He also told ABC News that these remains were found about a quarter of a mile away from property once owned by Shermantine's family in Calaveras County.
A second search conducted Friday on property that formerly belonged to Shermantine and his family led to a second set of partial human remains along with articles of clothing.
"The clothes they found match the exact description of what Chevy was wearing that day my wife dropped her off at school," Wheeler said. "My wife still remembers exactly what she had on the last time we saw her."
The girl's father was also told by investigators that the remains were found wrapped inside a blanket and that DNA tests conducted by the Department of Justice would provide a positive identification.
The sheriff's department said it's too early to tell how many different bodies they've found. They say the next step is sending all the tagged items to the Department of Justice for DNA analysis.