A man who wanted the death penalty for the 1996 slaying of a husband and wife has killed himself on Georgia's death row.

Daniel Colwell, 41, was found dead in his cell Sunday night and prison officials determined he committed suicide by hanging himself.

Department of Corrections spokeswoman Scheree Lipscomb said Monday that Colwell had been on suicide watch last year, but was no longer on it.

Diagnosed with paranoid schizophrenia and manic depression, Colwell drove to a Wal-Mart parking lot in Americus and gunned down Mitchell and Judith Bell of Ellaville. He then drove to the police department where he confessed and asked that he be put to death in Georgia's electric chair.

Colwell was not the first to commit suicide on death row. In 1989, John Everett Castell -- sentenced to die for killing a Stephens County tax official -- hanged himself in his cell with shoelaces.