A prison is Pennsylvania is reporting the second inmate death at the facility in less than a month.
The state prison in Camp Hill said a corrections officer performing a routine security check around 4 a.m. Tuesday discovered 56-year-old Warren Pennick unresponsive in his cell.
Pennick had been at the prison since April 28. He was serving a 20- to 40-year sentence for third-degree murder in Montgomery County.
An autopsy will be conducted by the Cumberland County coroner's office.
In January, Pennick pleaded guilty but mentally ill to the Halloween 2012 stabbing death of his 79-year-old mother in their Lansdale home.
Investigators said after killing his mother, Pennick, left the 7-inch knife on her chest, changed clothes and walked to the police station to confess.