Once touted as a criminal justice reform success story, Vallejo resident Marvin Mutch is back in court for all the wrong reasons. The 69-year-old, who was paroled in 2016 after serving roughly four decades for a 1975 murder, pleaded guilty today in federal court in Sacramento to possessing child sexual abuse material and to being a felon in possession of ammunition, following a search of his home last year.
According to a press release from the U.S. Attorney's Office for the Eastern District of California, agents executed a search warrant at Mutch’s Vallejo residence in May 2025 and seized electronic devices containing "tens of thousands" of depictions of the sexual exploitation of children, including images involving toddlers. Investigators also reported finding a privately manufactured ghost gun, eight rounds of ammunition in the center console of Mutch’s vehicle and narcotics, with the Solano County Sheriff’s Office and the FBI Violent Crime Task Force assisting the operation. Prosecutors say U.S. District Judge Dena Coggins is scheduled to sentence Mutch on Aug. 28, 2026, and that he faces statutory maximum penalties of up to 20 years in prison on the child sexual abuse material count and up to 15 years on the ammunition count.
1975 conviction and parole
Mutch was convicted in 1975 of murdering 13-year-old Cassie Riley in Union City and spent about 40 years in state prison before he was paroled in 2016. After his release, his case and later work as an advocate for incarcerated people drew significant Bay Area attention and became the focus of a documentary that revisited the killing and its aftermath. The San Francisco Chronicle reported on his 2025 arrest and the federal allegations that followed.
Prosecutors and next steps
CBS Bay Area reported that Mutch entered his guilty pleas on Friday and that Assistant U.S. Attorneys Adrian T. Kinsella and Sam Stefanki are handling the prosecution. The outlet summarized federal court filings that detail the scale of the digital evidence seized during the May 2025 search and noted the coordination between state and federal investigators. With the plea now on the record, the case moves into the sentencing phase, where filings and arguments will shape how long Mutch could be returned to federal custody at his August hearing.
Legal implications
The federal charges carry steep potential penalties on paper. Possession of child sexual abuse material carries a statutory maximum of 20 years in prison and a $250,000 fine, while being a felon in possession of ammunition carries a statutory maximum of 15 years and a $250,000 fine, according to the U.S. Attorney's Office for the Eastern District of California. Prosecutors note that the actual sentence will be set by the judge after reviewing the federal Sentencing Guidelines, any plea agreement and other statutory factors. The office also states that the case is being prosecuted as part of Project Safe Childhood, a nationwide initiative that brings together federal and local agencies to pursue cases involving the sexual exploitation of children.
What comes next in Vallejo
The renewed federal case has reignited scrutiny of a long-running Bay Area story, including the high-profile Riley homicide and questions that surfaced after Mutch’s release, the San Francisco Chronicle reports. The Solano County Sheriff’s Office continues to coordinate with federal partners as the matter approaches the August sentencing date, and the final outcome will be set in the coming months through the federal court record.
