‘Speed Freak Killer’ responsible for multiple California deaths in 1980s and ’90s dies in prison
09/22/2026 9:10 am PDT
SACRAMENTO, Calif. (TCN) -- A 60-year-old man serving a condemned sentence in connection with a series of killings and disappearances in the 1980s and 1990s has died in prison.
Wesley H. Shermantine died Sept. 17, according to a press release from the California Department of Corrections and Rehabilitation. Shermantine and his high school friend Loren Herzog became known as the “Speed Freak Killers” after they were linked to multiple deaths and disappearances in San Joaquin County, California, in the 1980s and 1990s, KTLA reports. Investigators believe they could be responsible for as many as 20 deaths.
SFGate reports Herzog and Shermantine became infamous as teens for their abusive behavior and their addiction to methamphetamine, also known as speed. More than 12 people associated with the pair disappeared mysteriously.
An investigation began in earnest following the disappearance of a 25-year-old woman in 1998, according to KTLA. The victim, Cyndi Vanderheiden, was reportedly last seen alive with Shermantine and Herzog. Her blood was later found in Shermantine’s car, and the investigation into her disappearance and death led detectives to find 1,000 bone fragments inside a well.
According to KTLA, Herzog and Shermantine were arrested in 1999. Shermantine was sentenced to death, and Herzog, who was found to have been coerced into confessing, was paroled in 2010. He committed suicide two years later.
Shermantine had been transferred to California State Prison Sacramento in 2001 from Santa Clara County and placed on condemned status for first-degree murder, according to the release. KTLA reports he was initially held on death row at San Quentin State Prison before California suspended executions.
In a statement, San Joaquin County District Attorney Ron Frietas said, “Today, our hearts are with the families of Cyndi Vanderheiden, Chevelle ‘Chevy’ Wheeler, Howard King III, Paul Cavanaugh, and everyone whose lives were shattered by the ‘Speed Freak Killers.’
“For decades, these families have carried a heavy, unbearable grief. While Wesley Shermantine’s death marks the final chapter of his legal sentence, it doesn’t erase the pain left behind. We stand with the victims’ loved ones today, and we will never forget the strength they’ve shown throughout this long nightmare.”
