John Kasianczuk had pleaded guilty to voluntary manslaughter in the Oct. 2010 death of 49-year-old Roberto Avalle at the State Correctional Institution in Graterford, Montgomery County.
Kasianczuk's lawyer said at Monday's sentencing hearing his client had been sexually abused as a child and Avalle had threatened to do the same thing to him before the August 22 attack. Avalle died about six weeks later of a brain hemorrhage.
Public defender John Kravitz said the remark trigged an episode of Post-Traumatic Stress Disorder.
Kasianczuk was serving a robbery sentence at the time of the killing. Avalle had recently arrived to serve a witness intimidation sentence.