LINDEN, Calif. >>  The search for more human remains in what appears to be a mass grave used by two men known as the "Speed Freak Killers" was suspended because of rain Monday, a day after authorities unearthed hundreds of bone fragments.

The grisly discoveries were at an old well near the rural Northern California town of Linden that death row inmate Wesley Shermantine claimed could hold 10 or more victims from a killing spree during the 1980s and 90s.

Along with bones, searchers dug out clothes, a purse and jewelry, on Sunday. The items were found 45 feet deep in the well on an abandoned cattle ranch, San Joaquin County sheriff’s spokesman Deputy Les Garcia said in a statement.

After two days of searching the site, investigators, public works employees and volunteers have found more than 300 human bones, Garcia said. They had planned to resume the search Monday, but rain prevented them from going in, he said.

"We are bringing the dirt and debris up using excavators and we’re searching piles. If it’s raining, we will wait," Garcia said before dawn.

Sunday marked the fourth straight day that remains were found with the help of a map prepared by Shermantine, who along with childhood friend Loren Herzog became known as the "Speed Freak Killers" after their arrests in 1999. The map led to burial locations in San Joaquin and Calaveras counties.

Shermantine was convicted of four murders and sentenced to death.

Herzog was convicted of three murders and sentenced to 77 years to life in prison, though that was later reduced to 14 years. An appeals court tossed his first-degree murder convictions after ruling his confession was illegally obtained.

Herzog was paroled in 2010 to a trailer outside the High Desert State Prison in Susanville. He committed suicide outside that trailer last month after Sacramento bounty hunter Leonard Padilla told him Shermantine was disclosing the location of the well along with two other locations.

A piece of a human skull and bones found Saturday at the San Joaquin County well will be sent to the Department of Justice in the hopes of identifying them through DNA testing, Garcia said.

Dental records identified remains found Thursday in Calaveras County, on property once owned by Shermantine’s family, as those of 25-year-old Cyndi Vanderheiden, who disappeared in 1998.

Another set of remains was found Friday in the same area, and the parents of 16-year-old Chevelle "Chevy" Wheeler, who disappeared in 1985, said authorities told them that’s where their daughter was believed to be buried.

Crews are expected to be searching the ranch in Linden for several days, at what Garcia has said would be a "slow and tedious" pace.