COLUMBUS, Neb. -- A man convicted of killing a Columbus teenager in 1989 has died while in custody. 

The Department of Corrections said 51-year-old Daniel Gondringer died Monday at a Lincoln Hospital. He was being treated for a medical condition. 

Gondringer was 19 when he was convicted of second-degree murder related to the death of 13-year-old Kimberly Martin at Gondringer's Columbus home in 1989. 

He was serving life in prison, but was eligible for a parole hearing this December.