The Nebraska Department of Correctional Services says 50-year old Kak Thoan died this week.
He was found unresponsive in his cell at the Reception and Treatment Center in Lincoln.
Staff members started CPR and contacted emergency medical services.
The inmate was taken to a Lincoln hospital where he was later pronounced dead.
The Nebraska State Patrol will conduct the investigation into his death.
Thoan’s sentence began on September 9th, 2016.
He was serving a 55 to 60 year sentence for manslaughter out of Douglas County.
As is the case whenever someone dies in custody, under state law, a grand jury will investigate.
(Picture from Nebraska Department of Correctional Services)