ST. LOUIS (AP) _ Missouri's oldest death row inmate is scheduled to be executed Tuesday for the 1996 shooting death of a sheriff's deputy. But attorneys for 74-year-old Cecil Clayton are asking the U.S. Supreme Court and the state's governor to spare his life, arguing that Clayton has brain damage from a 1972 sawmill accident and worsening dementia.
Here's a look at the case:
Clayton was convicted of fatally shooting Christopher Castetter, a sheriff's deputy in rural southwest Missouri's Barry County. Castetter, then 29 and a father of three, was investigating a suspicious vehicle near Cassville on the night before Thanksgiving in 1996 when he was shot in the forehead while he was in his car. His vehicle was found against a tree with the engine racing and wheels spinning. Castetter died at a hospital the next day.
Clayton's attorneys argue that he suffers from lingering effects of a 1972 sawmill accident in which a piece of wood shot through his skull. Surgeons removed about 8 percent of Clayton's brain, including one-fifth of the frontal lobe that governs impulse control and judgment.
His lawyers say Clayton has an IQ of 71 and that psychiatric evaluations indicate he doesn't understand the significance of his scheduled execution or the reasons for it, making him ineligible for execution under state and federal law.
Clayton's attorneys have appealed the case to the U.S. Supreme Court and asked the Missouri governor for clemency, insisting that the inmate's deteriorating mental health has left him convinced his conviction was a plot against him. They argue that Clayton also believes God will rescue him at the last-minute, ``after which time he will travel the country playing the piano and preaching the gospel.''
In part because of his dementia, the lethal injection would or would likely cause Clayton ``excruciating or tortuous pain and needless suffering'' and allow the state to use him as an experiment of its execution protocol on someone with severe brain damage.
The state countered by saying Clayton would be executed ``rapidly and painlessly'' in accordance with the constitutional protections against cruel and unusual punishment.
The Missouri Supreme Court declined to intervene Saturday in a 4-3 ruling. The court's majority concluded there's no evidence that Clayton, despite his brain injury, isn't capable of understanding his circumstances.
The dissenting opinion countered that Clayton's attorneys ``presented reasonable grounds to believe his overall mental condition has deteriorated and he is intellectually disabled.''
Clayton's claims of mental incompetence mirror those of Ricky Ray Rector, who was executed in 1992 in Arkansas for fatally shooting a police officer. His attorneys failed to sway then-Gov. Bill Clinton that he had been left brain-damaged by a self-inflicted bullet wound prior to his arrest.
If carried out, Clayton's execution would be Missouri's second this year. The state executed a record 10 people in 2014. Clayton's execution also is the first to be scheduled in Missouri for 6 p.m. Tuesday after decades of having lethal injections set to begin at 12:01 a.m. Wednesday.