The State of Missouri has carried out the execution of Cecil Clayton, for the November 1996 murder of Barry County Sheriff’s Deputy Christopher Lee Castetter.

Cecil Clayton (courtesy; Missouri Department of Corrections)

Cecil Clayton (courtesy; Missouri Department of Corrections)

The execution occurred after a delay of more than three hours while the U.S. Supreme Court considered the final legal attempts by Clayton’s attorneys to halt it. He was given a lethal dose of pentobarbital at 9:13 p.m. and appeared to quit breathing less than two minutes later. His official time of death was 9:21 p.m.

His final statement was, “They brought me up here to execute me.”

Clayton was convicted of killing Castetter when the deputy responded to a call from the home of Clayton’s girlfriend’s sister, who was concerned that Clayton was sitting in his truck in front of her home following a dispute with his girlfriend. Clayton shot Castetter in the forehead before going to the home of a friend, whom he told he had shot a police officer and asked to tell police the two had been together all evening watching television.

Clayton reportedly later told police of Castetter, “He probably should have just stayed home … He shouldn’t have smarted off to me.”

Clayton’s attorneys had argued that he was not competent to be executed, was not competent to help them in his defense, and was intellectually disabled. They raised these arguments in part because of a brain injury he suffered in a sawmill accident in 1972.

Several petitions in multiple courts were denied, including at the last those to the U.S. Supreme Court and the Missouri Supreme Court. Governor Jay Nixon (D) then denied an application for clemency, clearing the way for the execution to proceed.

It had been scheduled to happen as early as 6 p.m. Tuesday evening.

“Mr. Clayton was not a criminal before the sawmill accident,” said his attorney, Elizabeth Unger Carlyle in a statement released after his execution. “Medical experts who examined 74-year-old Mr. Clayton said he couldn’t care for himself, tried but couldn’t follow simple instructions, and was intellectually disabled with an IQ of 71 … The world will not be a safer place because Mr. Clayton has been executed.”

Castetter’s family was not convinced those brain injuries were as debilitating as Clayton’s attorneys claimed.

“Just him going to [his friend] Martin Cole, wanting him to say he was with him all evening, telling Martin that he just shot a cop, and then seeing two other police officers and asking if he should shoot them too, there is no doubt in my mind that Cecil knew what he had done,” said James Castetter, one of Christopher’s brothers who was a witness to the execution. He was joined by two other brothers of Castetter, a sister, and one sister-in-law.

Two attorneys witnessed the execution on the behalf of Clayton. His brother and son were making arrangements for his funeral.

Upon the completion of the death sentence, Governor Nixon, who had been Attorney General at the time of the murder and through several of the challenges to Clayton’s sentence, issued a statement reminding Missourians that Castetter is honored on the Law Enforcement Memorial next to the Capitol in Jefferson City.

“Our state is safer because there are brave officers, like Deputy Castetter, who are willing to sacrifice their own safety for that of others,” wrote Nixon.

Missouri is next scheduled to execute Andre Cole for the 1998 murder of a man who was visiting is ex-wife. His execution is scheduled to happen between 6 p.m. April 14 and 5:59 p.m. April 15.

Video: Christopher Lee Castetter’s brother James speaks following Clayton’s execution: