SIOUX FALLS, S.D. (AP) — A convicted murderer said in a letter written from death row that the South Dakota Supreme Court owes it not only to him but to the family of the prison guard he killed to allow his execution to take place in a timely manner. It’s the only way, he said, the guard’s family can get justice.

Eric Robert, 50, pleaded guilty to killing Ron Johnson during a botched prison escape at the South Dakota State Penitentiary and asked to be put to death. A judge determined in October that the crime merited the death sentence, and Robert was scheduled for execution the week of May 13.