Carman Deck in an undated photo from the Missouri Department of Corrections.
CNN  — 

Carman Deck, who was condemned to death following a double murder conviction and three trials, was executed Tuesday evening in Bonne Terre, Missouri, by lethal injection.

Deck was accused of fatally shooting James and Zelma Long in the back of the head and robbing them in 1996, when he was 30 years old. Police said he confessed to the killings, but Deck’s defense argued at trial it was a false confession.

Deck’s first conviction was overturned on appeal due to an error in jury instructions. He was sentenced to death a second time, but it was overturned by the US Supreme Court, which said Deck being shackled in court during the sentencing phase may have influenced the jury.

A third jury returned death verdicts in 2008, but a federal judge vacated the sentence, agreeing with Deck’s defense there was not enough evidence in the third penalty phase to warrant a death sentence.

In 2020, a federal appeals court ruled the judge’s decision to be in error and reinstated the death sentence. Further appeals to the US Supreme Court were denied.

“Tonight, justice was served,” said Anne Precythe, director of the Missouri Department of Corrections. Deck was pronounced dead at 6:10 p.m. CT.

Elizabeth Carlyle, an attorney for Deck, called his execution “unjust and immoral,” saying Deck “endured a pattern of abuse, neglect and abandonment, which was mitigating evidence the Missouri Supreme Court called ‘substantial.’ “

Close family members taught him to steal, the attorney said, leading to a prison sentence which “transformed him from a nonviolent thief into the person who committed two terrible murders,” the attorney said in a statement.

The third jury did not hear from anyone who could testify to his “horrific childhood,” she wrote.

“Due to the passage of time caused by the State of Missouri, the jury did not hear from a single live witness who knew Carman before the crime,” Carlyle said. “This botched process simply provides insufficient guardrails to support taking Carman’s life. Life imprisonment without parole would have been a just and adequate punishment for him.”

Members of the Long family witnessed the execution, but no members of Deck’s family were present, according to a corrections department spokesperson.

Deck’s execution was the fifth this year in the United States, according to the Death Penalty Information Center.

CNN’s Jennifer Feldman contributed to this report.