Eric Knysz, the man who killed Michigan State Police Trooper Paul Butterfield has been declared clinically brain dead after hanging himself while in prison, according to WZZM-13.

According to the news station, a spokesperson for the family has said that Knysz remains on a ventilator at Allegiance Health hospital in Jackson. Doctors are performing tests to see if his organs can be donated. Those tests are expected to be completed within 24 to 36 hours. Knysz is registered as an organ donor.

Earlier Tuesday, state prison officials would not release information regarding what happened before Knysz attempted suicide Monday.

Sources told WZZM that Knysz had been on suicide watch at the Mason County Jail, where he was held prior to being sentenced to life in prison for Trooper Butterfield’s September 2013 murder.

Knsyz, 20, was transferred to the custody of the Michigan Department of Corrections last Thursday following his sentencing and was sent where incoming state prisoners first go for screening - the Charles Egeler Reception and Guidance Center in Jackson.

Four days later, he attempted suicide with a bed sheet in his cell.

MDOC is investigating the suicide attempt, but there seems to be no indication as to when that investigation might be complete.