A 43-year-old prisoner was stabbed to death Sunday morning at Jessup Correctional Institution, state police said.
John A. O'Sullivan was found lying on the floor and bleeding by corrections officers. The officers had responded about 10 a.m. to a fight inside the prison.
O'Sullivan died at the prison, police said.
Officers took into custody several prisoners seen walking from O'Sullivan. No charges have been filed and the investigation continued into Sunday night.
In January, a 58-year-old prisoner was beaten to death in his cell at Jessup. And in July of last year, another Jessup prisoner pleaded guilty to killing his cellmate in 2012.