Wesley Shermantine, one half of the notorious “Speed Freak Killers,” has died in prison while serving a death sentence for four murders tied to a yearslong killing spree in the San Joaquin Valley.
Shermantine died Thursday at California State Prison, Sacramento, state corrections officials announced Friday. He was 60.
A doctor pronounced him dead around 6 p.m. at the prison. The Sacramento County Coroner’s Office will determine his cause of death…