California Department of Corrections, File, Associated Press
FILE - In this undated file photo provided by the California Department of Corrections, Wesley Shermantine is shown. Information provided by the California death row inmate who was one of the two notorious "Speed Freak Killers" led to the discovery Friday Feb. 10, 2012 of a second set of human remains, this time believed to belong to a 16-year-old girl who went missing nearly three decades ago.

SAN FRANCISCO — Authorities searching with the help of a convicted serial killer have found more human remains in Northern California.

San Joaquin County sheriff's spokesman Deputy Les Garcia says a skull fragment and other bones were found Saturday in an abandoned well, near the town of Linden.

It was the third straight day authorities found remains by following a map prepared by convicted serial killer and death row inmate Wesley Shermantine.

The latest discovery was the first found at the old cattle ranch well, where Shermantine said 10 or more victims could be.

It was not clear whether the remains belonged to one or more people, and Garcia says they had not yet been identified.

The search has been called off for the night but is set to resume Sunday.