Shermantine and Loren Herzog were suspected of killing more than 70 people in a methamphetamine-fueled spree centered in San Joaquin County.

Wesley Shermantine, known as one of the notorious “Speed Freak Killers,” died at California State Prison, Sacramento on Thursday, the California Department of Corrections and Rehabilitation said.

A detective who led the investigation into a notorious serial killer hopes that someone will come forward to reveal the location of his victim’s heads following his death. Double murderer John Sweeney ...