Two inmates found unresponsive in their cells at San Quentin State Prison in early December both died of drug overdoses, according to the Marin County coroner.
The deaths of Herminio Serna and Joseph Perez renewed attention on the state's struggles to reduce the flow of illegal drugs into the prison system. California has spent tens of millions of dollars in recent years to stop drug smuggling, but dozens of inmates continue to die every year from overdoses.
When state prison officials announced their deaths, which took place on Dec. 3 and 4, they did not officially link the deaths to illegal drug use. But Marin County public health officials said then that the cases took place as their agency's paramedics had seen a spike in calls from the prison related to opioid overdoses.
Serna, a 53-year-old gang member sentenced to death for multiple murders in San Jose, died from acute and prescription drug intoxication, according to Roger Fielding, chief deputy coroner of the Coroner Division of the Marin County Sheriff's Office. The office said Serna also suffered from chronic substance abuse, a significant condition contributing to his death.

