A California murderer who spent four decades in prison for beating and then drowning a 13-year-old girl is back behind bars after allegedly being caught with disturbing child pornography, according to officials.
Marvin Lee Mutch, 68, was released in 2016 after spending 40 years in San Quentin Prison for murdering Cassie Riley in 1974, later becoming the subject of a documentary, “The Trials of Marvin Mutch.”
Mutch was just 18 at the time of the murder — and out on bail awaiting trial for allegedly kidnapping another 13-year-old girl at knifepoint when he drowned Riley.
He was taken into custody in Vallejo last Thursday for possession of child sexual abuse material, booking data from the Solano County Sheriff’s Office shows.
The murderer — who has always maintained his innocence — was serving as a director of advocacy for the Prisoner Reentry Network when he was re-arrested.
Several electronic devices were also seized for “forensic examination,” the sheriff’s office said.
Mutch is being held on a $300,000 bail and faces charges of possession of child pornography, being a convicted felon in possession of a firearm, being a convicted felon in possession of ammunition and possession of a controlled substance while armed.
“The investigation is ongoing, and additional charges may be forthcoming,” the sheriff’s office said.
Mutch is due in court again on Tuesday for a hearing, booking data shows.
The body of 13-year-old Cassie Riley was discovered in September 1974 in a creek bed close to her home. She had been beaten and held underwater until she died, prosecutors said at the time.
A jury took just five days to find Mutch guilty of murder.
Mutch was sentenced to seven years in prison in 1975 but always maintained his innocence.
He spent the next 40 years in San Quentin Prison after being repeatedly denied parole, eventually securing his release in 2016.
Mutch’s Prisoner Reentry Network rushed to his defense after his latest arrest last week, claiming he is facing “persecution.”
Mutch “has been accused of crimes he did not commit,” the group insisted in a statement shared on Sunday along with an online fundraiser to pay for the convicted child-murderer’s legal costs.
“Marvin has supported the interests of California’s prisoners for the past 50 years and this persecution is the cost of his advocacy for human rights,” the post read — sparking fury in the comments.
“You must be joking,” one person wrote, while another added: “Every single person who donated to this is sick.”
The Prisoner Reentry Network did not respond immediately to requests for comment.
