Cecil Clayton, a convicted cop-killer in the United States, is scheduled to be executed on Tuesday, Mar. 17. The 74-year-old is Missouri's oldest death row inmate.

Update: The execution has been put on hold. Officials will wait until the U.S. Supreme Court decides whether a stay of execution should be issued.

Clayton is scheduled to be executed by injection for shooting a sheriff's deputy dead in 1996. He has been asking the state's governor as well as the U.S. Supreme Court to allow clemency. His attorneys argue that the convict suffers from dementia. Clayton is apparently missing a part of his brain [image] after he had met with a sawmill accident in 1972.

Clayton’s last-minute appeal is based on his claim that he has been suffering from intellectual disability and mental illness. The attorneys say that his illness makes him ineligible for the capital punishment. The highest court in Missouri earlier rejected Clayton's appeal over the weekend. The convict has now appealed to the Supreme Court.

Clayton shot down Christopher Castetter in rural southwest Missouri's Barry County. The father of three was 29 when he was killed. The incident took place before the Thanksgiving in 1996. Castetter was shot in the forehead while he was in his car which was later found against a tree with its engine wheels spinning and running fast. Castetter died later at a hospital the following day.

According to Clayton’s lawyers, he was injured in sawmill accident in 1972. He was hit by a piece of wood shot through his skull. The injury forced doctors to remove a small part of his brain. A fifth of Clayton’s frontal lobe, amounted to just less than eight percent of his brain, was surgically removed.

Clayton’s lawyers argue that the convict had become suicidal, paranoid, alcoholic, depressed and hallucinatory after the surgery. He was also prone to violent outbursts, they argue. According to the defence, a couple of doctors have declared Clayton incompetent. However, the Missouri court observed that the convict was aware of the reason why he had been sentenced to be executed. This makes him eligible for the death penalty.

Three of the seven judges believed that Clayton was entitled to a competency hearing. "The majority's decision to proceed with the execution at this time and in these circumstances violates the Eighth Amendment ban on cruel and unusual punishment," they wrote in a statement.

Contact the writer: s.mukhopadhyay@ibtimes.com.au

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