Carlos Montenegro, 39, died Monday evening after two fellow inmates attacked him on the upper tier of a housing unit at California State Prison, Sacramento, in Folsom. Officers fired five less-lethal rounds to break up the assault, and paramedics pronounced him dead at 7:24 p.m. Investigators are treating the death as a homicide.
According to KTLA, the deadly incident unfolded around 6:43 p.m. on Oct. 26, when correctional officers witnessed two inmates attacking another prisoner. The two men, identified as Justin Castro and Luis Mendoza, ignored orders to get down. Officers then fired five less-lethal 40mm impact rounds to stop the assault.
The report notes that two improvised weapons were recovered at the scene, according to the California Department of Corrections and Rehabilitation. Castro and Mendoza were placed in restricted housing pending an investigation.
Lifesaving Efforts Fell Short
As staff called 911, prison personnel began performing lifesaving measures on Montenegro while taking him to the prison's treatment and triage area. Paramedics ultimately pronounced him dead at 7:24 p.m., about 40 minutes after the attack began, per the same account.
The prison's Investigative Services Unit and the Sacramento County District Attorney's Office are investigating the death as a homicide. The state Office of the Inspector General has also been notified. No motive for the attack has been provided, and it is not yet known whether prosecutors will file new charges.
Who Was Involved
Montenegro was serving a six-year sentence for assault with a deadly weapon, a second-strike offense, the report states. Castro, 47, is serving a life sentence with the possibility of parole under California's three-strikes law, and Mendoza, 33, is serving a life sentence with the possibility of parole for attempted second-degree murder, second-degree robbery, assault with a semiautomatic firearm and criminal gang activity.
Details of the men's convictions also appear in KCRA's coverage, which reports that Castro's sentence stems from attempted second-degree murder, first-degree burglary, second-degree robbery, kidnapping and carjacking. KCRA also reports that Mendoza received sentence enhancements for firearm use and street gang acts in the commission of a serious felony, per CDCR.
A Violent Month at the Folsom Prison
The Oct. 26 killing was the second homicide at the Folsom prison this month, KTLA reports. On Oct. 6, CDCR officials said they were investigating the death of a 47-year-old inmate as a homicide after he was attacked by another inmate while being escorted on a golf cart. The department's California Department of Corrections and Rehabilitation has posted a notice on that earlier death.
The violence fits a statewide pattern that prison officials have struggled to contain. The Los Angeles Times reported in September that a killing at Pelican Bay State Prison was the 17th homicide in the California prison system this year, compared with 30 for all of 2025. Last year's surge in inmate killings and attacks on staff prompted prison officials to curtail privileges, restrict movement and increase searches for weapons and contraband at most facilities.
The Folsom prison has seen trouble before. An earlier Times report said California State Prison-Sacramento recorded four homicides in 2024 and three in the year that article described, and that a melee involving about 40 inmates broke out there on March 5, leaving five prisoners hospitalized with non-life-threatening injuries.
