STOCKTON (CBS13) – A prison inmate at the California Health Care Facility in Stockton was been killed and another inmate is being investigated as his possible killer.

On Sunday around 4:30 p.m., 40-year-old inmate Aaron Coderre was found unresponsive in the showers. He had suffered from an attack with a weapon and was declared dead by an on-site physician just minutes later, according to a statement from the California Department Of Corrections and Rehabilitation (CDCR).

Aaron Corderre and Joshua Rudiger (l-r) (credit: CDCR)

CHCF determined that inmate Joshua Rudiger, 42, was in the showers at the same time as Codere. He was placed in segregated housing, pending an investigation. Corderre’s killing remains under investigation by the San Joaquin District Attorney’s Office and CHCF’s Investigative Services Unit.

Coderre was serving a life sentence with the possibility of parole for first-degree attempted murder with an enhancement of personal use of a dangerous weapon or deadly weapon. Rudiger was serving also serving a life sentence with the possibility of parole for second-degree murder and assault with force likely to produce great bodily injury.

The facility provides medical and mental health care to inmates who have the most severe and long-term needs.