Arizona carried out its first execution since 2014 on Wednesday, putting to death a prisoner convicted of killing a student more than four decades ago, state prison officials said.
Clarence Wayne Dixon, convicted of fatally stabbing and strangling Arizona State University student Deana Bowdoin in 1978, was put to death by lethal injection at 10.30am local time at the state prison in Florence, Arizona, Frank Strada, deputy director of the state's Department of Corrections, told a news conference.
He became the sixth person executed this year in the US, the non-profit Death Penalty Information Centre reported.
His lawyers had filed a number of appeals, arguing their client suffered from paranoid schizophrenia and did not know why he faced capital punishment.
“Mr Dixon really doesn't understand the claim because he lives in his head … He lives in these alternate realities,” lawyer Eric Zuckerman said on Tuesday at a hearing before a San Francisco court, which rejected his appeal.
A final request for a stay of execution was denied on Wednesday by the US Supreme Court.
In his last words, Dixon said, “Maybe I'll see you on the other side Deana. I don't know you and I don't remember you,” according to NBC News, quoting a reporter from another news outlet who witnessed the execution.
It was the first time the US state of Arizona had carried out a death sentence since the 2014 execution of Joseph Wood, when it took nearly two hours for a two-drug cocktail injection to take effect, and witnesses said he snorted and gasped before he died. Corrections authorities said Wood was comatose and never in pain.
Afterwards, Arizona halted executions. Then in 2017, a federal judge accepted sweeping reforms of the state's death penalty protocols, including an agreement to stop using certain drugs.
The state said it would limit the authority of the director of the Department of Corrections to change drugs and allow a prisoner time to challenge any drug changes.
Several state governments and the US federal government have struggled in recent years to obtain drugs used in lethal injection cocktails, while legal and ethical questions swirl around capital punishment.
Dixon was sentenced to death in 2008, about 30 years after Bowdoin was killed. The case went unsolved until 2001, when investigators matched Dixon's DNA with evidence found at the scene. At the time, Dixon was serving life in prison for a 1986 sexual assault.
Pinal County Superior Court Judge Robert Olson ruled last week that Dixon was mentally fit to be executed. The US Supreme Court has ruled in the past that the execution of mentally disabled people is unconstitutional.
Agencies contributed to this report