One inmate fatally struck a fellow prisoner and critically wounded another at a central California prison, officials said Friday.
They said Jonathan Watson, 41, used a walking cane to cause multiple head wounds to both victims at the California Substance Abuse Treatment Facility and State Prison in Corcoran on Thursday.
Both were taken to an outside hospital, but one died en route and the other remained in critical condition.
Watson has served 10 years of a life sentence from Humboldt County for first-degree murder and discharging a firearm causing great bodily injury or death.
The slain inmate was David Bobb, 48, who was serving a life sentence from San Diego County for aggravated sexual assault of a child under 14 years old.
The Associated Press found in a 2015 analysis that male sex offenders were being killed at a rate double their percentage in California's prison population, often because they are targeted by other inmates for their crimes against children.
The prison houses more than 5,400 inmates and specializes in substance abuse treatment.