Yard stabbing marks second killing at High Desert State Prison this month, officials say

A man was killed by two fellow inmates at a Susanville jail on Monday, officials said, marking the second killing at High Desert State Prison this month.

According to a news release, prison staff witnessed inmates Jose R. Castillo and Victor M. Zapien attack inmate Richard Prieto in the D yard of the prison facility, where Prieto, 44, suffered puncture wounds to his chest, back, head and neck. Officers said they fired warning shots and used chemical agents to diffuse the altercation, at which point staff began life-saving measures.

According to the release, Prieto was declared dead at 3:02 p.m Monday. Zapien and Castillo were placed in segregated housing until an investigation can be completed, officials said, and two metal weapons crafted by inmates were found at the scene.

Castillo had been sentenced to six years in prison for assault with a deadly weapon on a peace officer/fireman in 2014, but he received an additional six years for possession/manufacture of deadly weapon by a prisoner. Zapien was sentenced to life in prison, with the possibility of parole, in 2014 for first-degree murder.

On Jan. 7, a similar incident occurred at High Desert in which two inmates fatally stabbed fellow inmate Richard Leyva in the yard of Facility C.

According to the release, the prison employs a staff of more than 1,200 to oversee its 3,145 minimum-, medium- and maximum-security inmates.