WEST TERRE HAUTE, Ind.  – The man who admitted to killing a West Terre Haute teen has died in prison.

In a plea agreement made in July of 2015, Clinton Mackey pleaded guilty to voluntary manslaughter and was sentenced to 40-years in prison. A murder charge was dropped.

Mackey admitted that he stabbed 19 year old Erica Case over 30 times at a West Terre Haute home on September 6, 1998.

A spokesperson for the Indiana Department of Corrections said Mackey’s manner of death was suicide at the New Castle Correctional Facility.