Orange, California — A 54-year-old man has received a 10-year federal prison sentence for his role in a violent attack on a fellow inmate at the Orange County Jail. Robert Amezcua was sentenced on Tuesday by U.S. District Judge Fred Slaughter after being found guilty in January of violent crime connected to a racketeering case involving the Mexican Mafia.
The incident occurred on December 31, 2019, when Amezcua and another inmate assaulted Michael Cooper at the Theo Lacy Facility. Prosecutors detailed how Amezcua struck Cooper approximately 20 times, while his accomplice used a razor blade to inflict serious injuries by slashing the victim’s throat. Despite the brutal nature of the attack, Cooper survived.
Amezcua was one of 31 defendants charged in a 2022 federal racketeering indictment associated with the Orange County chapter of the notorious Mexican Mafia. His co-defendant, Mher Darbinyan, 50, is currently serving a 30-month sentence for his part in the assault, having been sentenced in May 2024.
Another co-defendant, Robert Martinez, 43, is facing trial in August on charges related to the jail attack, along with additional allegations. To date, four of the 31 defendants in the racketeering case have been convicted after trial, while 16 have pleaded guilty. Three other defendants are set to face trial in July, with eight more scheduled for August.
The indictment highlighted the inner workings of the gang, revealing that reputed leader Johnny Martinez allegedly ordered Cooper’s attack from within the confines of Calipatria State Prison. Martinez and co-defendant Omar Mejia discussed coordinating the assault due to Cooper’s actions that had caused friction within the gang. Cooper had reportedly ordered an attack on another gang member without proper authorization and was suspected of instigating a police raid against the organization.
Notably, this was not Cooper’s first assault. He had previously been attacked in January 2018 but managed to survive, only to face the brutal encounter again nearly two years later.
As the legal proceedings continue against the remaining defendants, the case sheds light on the violent dynamics within prison gangs and the lengths to which they will go to enforce their authority and silence perceived threats.