California prison officials investigate inmate’s death after attack in dayroom
California prison officials are investigating the death of an inmate at High Desert State Prison near Susanville as a potential homicide.
Joseph Reagan, 44, died Tuesday evening following an alleged attack by fellow inmate Bryan Cook, according to the California Department of Corrections and Rehabilitation.
Cook, 49, was convicted of second-degree murder in 2014 for killing his roommate, Michael Jones, in Stockton and dismembering the body. According to the Stockton Record, Cook was caring for Jones, who was disabled, and had tried to conceal the killing by leaving Jones’ body in Groveland, Tuolumne County.
He was also convicted last year in the 2018 killing of an inmate at Calipatria State Prison in Imperial County along with another inmate, Charles Demar, before being transferred to the Lassen County prison.
The attack occurred just before 7 p.m. in the dayroom of the high-security facility. Reagan was taken to the prison infirmary, where he was pronounced dead. Officers later recovered a homemade weapon believed to have been used in the assault, CDCR said.
Reagan had been serving a 10-year sentence for vehicular manslaughter in Tulare County, which was extended due to “multiple in-prison offenses, including assault with a deadly weapon,” according to the department.
The Lassen County District Attorney’s Office, the county coroner, and the prison’s Investigative Services Unit are conducting the investigation.
Cook has been moved to restricted housing.
This story was originally published June 11, 2025 at 10:32 AM.
