Lawyers for death row inmate Robert Henry Moormann have asked the Arizona Supreme Court to stay his scheduled Feb. 29 execution.
In a 21-page motion filed Tuesday, Moormann's attorneys say he was diagnosed in early childhood as being mentally retarded and the state can't execute him because of that fact.
The 63-year-old Moormann was sentenced to death for the 1984 death of his adoptive mother while on a prison furlough.
Moormann was serving a prison term of 9 years to life for kidnapping when the state let him out on 3-day "compassionate furlough" to visit his adoptive mother at a Florence motel.
Authorities say Moormann beat, stabbed and suffocated the woman before meticulously dismembering her body.
Moormann's attorneys used an insanity defense, but a jury convicted him of 1st-degree murder.
(source: Associated Press)