California prison officials are investigating the killing of a Livermore man serving time in Kern Valley State Prison. Guards found Jacob Kober, 35, in his cell around 7:20 p.m. Thursday, seriously injured and unresponsive,

State corrections officials have launched a homicide investigation after a convicted killer from Alameda County died following an incident at a Central Valley prison Thursday evening.

A Livermore man who was convicted of a 2012 murder died in prison Thursday after an apparent attack with an inmate-manufactured weapon, prison officials said. Jacob Kober, 35, was an inmate at Kern Valley State Prison.

Jacob Kober, 35, was stabbed multiple times in his Kern Valley State Prison cell on Thursday, authorities said. His cellmate, identified as 39-year-old Matthew Perez, also sustained injuries consistent with a “prison manufactured weapon,

An inmate at Kern Valley State Prison died Thursday after an apparent attack with an inmate-manufactured weapon, his cellmate also suffering injuries, prison officials said. Jacob Kober, 35, was pronounced dead at 7:52 p.