JACKSON, Ga. (AP) — Georgia on Friday executed its sixth inmate this year, the most in any calendar year in the state since the death penalty was reinstated four decades ago.

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. Warden Eric Sellers told witnesses the time of death was 12:29 a.m.

Conner didn't make a final statement and declined to have a prayer said for him.

The warden left the room at 12:15 a.m. Records from past executions show the lethal drug generally begins to flow within a couple of minutes of the warden leaving the room, but that is not visible to news media witnesses.

Georgia executed five inmates last year and in 1987. Only five states have carried out death sentences this year, for a total of 15 executions. Aside from the six in Georgia, six inmates have been executed in Texas and one each in Alabama, Florida and Missouri.

Lawyers for Conner had argued that imposing the death penalty after he's spent 34 years on death row was unconstitutional cruel and unusual punishment and amounted to double jeopardy, which is when someone is punished twice for the same crime.

"Due to the extraordinary delay in this case, Mr. Conner has already been subjected, in effect, to a life sentence under exceptionally severe penal conditions," his lawyers wrote in a court filing. "To top this punishment with the permanently harmful indignity of execution would be excessive and disproportionate punishment, prohibited by the Eighth Amendment."

They also said Conner was raised in poverty in a home where extreme violence and substance abuse were the norm and exhibited signs of mental impairment that led his teachers to believe he was intellectually disabled from an early age.

In a clemency petition, his lawyers described Conner's father as someone who was feared by the community and his family, who regularly cut his wife and children with a knife and fired a gun at them. As a result, Conner "fell into the pattern modeled by those in his family," his lawyers wrote in a clemency application.

But details of his background weren't provided to the trial jury or to appellate courts because he had ineffective lawyers and because of strict procedural rules, his lawyers argued.

His difficult 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.

Those arguments were rejected by the State Board of Pardons and Paroles, the only entity authorized to commute a death sentence in Georgia, and by state and federal courts.

Conner spent the evening of January 9, 1982, drinking and smoking marijuana at a party with his girlfriend and other friends, including J.T. White. They then returned to the home Conner shared with his girlfriend in Milan, about 150 miles southeast of Atlanta.

His girlfriend went to bed, and Conner and White took a nearly empty bottle of bourbon and left on foot in search of more alcohol. Conner told police he and White were walking down the road when White told Conner he wanted to sleep with his girlfriend. That led to a fight, during which Conner told police he hit White with the bottle and beat him with a stick, the documents say.

Conner went home and woke his girlfriend and told her he'd had a fight with White and thought he was dead, according to court documents. Before they left town, Conner told his girlfriend he had to be sure and walked to a drainage ditch. She heard a thud and Conner told her he was sure and they left, according to court documents.

The couple was later found hiding in a hay barn. White's body, with a badly beaten face, was found in the ditch.

While Conner's execution was the sixth in 2016, he was also the ninth inmate put to death by the state since Sept. 30, the most in a 12-month period since the death penalty was reinstated in 1976. The state's previous record for a 12-month period was set when seven inmates were put to death between October 2001 and August 2002.