According to court documents, Conner beat his friend JT White to death on January 9, 1982 in the town of Milan, about 150 miles southeast of Atlanta, after a night of heavy drinking.
A man convicted of beating a friend to death with a stick during a drunken fight over a woman 34 years ago was executed in Georgia on Friday, a state official said.
While Conner's execution was the sixth in 2016, he was also the ninth inmate put to death by the state since September 30, the most in a 12-month period since the death penalty was reinstated in 1976.
Conner, as a result, 'fell into the pattern modeled by those in his family'. The board is the only entity in Georgia authorized to commute a death sentence. John Wayne Conner, 60, was put to death for beating a friend to death during an argument after a night of partying in January 1982, the AP reports.
His girlfriend went to bed, and Conner and White took a almost empty bottle of bourbon and left on foot in search of more alcohol.
"So I got mad and we got into a fight and fought all the way over to the oak tree and I hit him with a quart bottle", Conner said.
"For young John Wayne Conner, normalcy included extraordinary familial violence that frequently involved knives and guns; regular drug and alcohol abuse; and brutal physical, sexual and emotional abuse", the clemency application read.
He exhibited signs of mental incompetence, and his teachers believed he was mentally impaired from an early age.
On Thursday, the Georgia Supreme Court declined to halt his execution.
Conner's attorneys asked the Georgia Board of Pardons and Paroles to spare his life, pointing to his horrific childhood and violent father.
Conner was allowed to present evidence seeking to prove intellectual disability to a federal court several years ago. That court denied his motion for a stay and rejected all his claims, which included that he is intellectually disabled, that his trial attorney rendered "ineffective assistance of counsel", and that it is unconstitutionally cruel and unusual punishment to execute him after 34 years. His lawyers are appealing that denial to the Georgia Supreme Court.
His hard background and mental impairment do not excuse what he did, but if that evidence had been presented, Conner might have been spared the death penalty, his lawyers argued.
He also taught himself to paint by watching Bob Ross' "The Joy of Painting" and other programs on television, and gives his artwork to family, legal representatives and members of the prison community, his lawyers wrote.