News Releases

MCSP Investigating Homicide of Incarcerated Person

IONE – Mule Creek State Prison officials are investigating the death of Robert Aranda as a homicide.

At approximately 1:40 p.m. on Thursday, Feb. 2, Aranda was found unresponsive in the cell with what appeared to be several injuries, including stab wounds. Staff immediately began life-saving measures, and transported him to the prison’s Treatment and Triage Area. Aranda was pronounced dead at 2:13 p.m. His next-of-kin has been notified, as well as the Office of the Inspector General. The Amador County Coroner will determine Aranda’s official cause of death.

His cellmate, Alexander Mateuz, has been identified as the alleged attacker, and he has been rehoused in the prison’s administrative segregation unit while this is investigated.

Aranda, 23, was convicted to state prison from Los Angeles County in November 2021 to a 13-year sentence for two counts of second-degree attempted murder with the use of a firearm.

Mateuz, 38, received a life with parole sentence from Los Angeles County in August 2008 for assault with a firearm as a third-striker, use of a firearm, and an enhancement of a street gang act in the commission of a violent felony.

MCSP, which opened in 1987, houses more than 3,800 minimum-, medium- and maximum-security incarcerated people. The prison, located in Amador County, provides educational, medical and mental health services.


Contact: CDCR Press Office