Georgia on Wednesday carried out its first execution this year, putting to death a man convicted of killing his 73-year-old neighbor 25 years ago.

J.W. Ledford's time of death was 1:17 a.m., after an injection of compounded barbiturate pentobarbital at the state prison in Jackson, Warden Eric Sellers told witnesses. Ledford, 45, was convicted of murder in the January 1992 stabbing death of Dr. Harry Johnston in Murray County, northwest Georgia.

Ledford smiled broadly as witnesses entered the execution viewing area. When given a chance to make a final statement, he appeared to quote from the movie "Cool Hand Luke."

"What we have here is a failure to communicate. Some men you just can't reach," he said, later adding, "I am not the failure. You are the failure to communicate."

"You can kiss my white trash ass," he added, continuing to smile.

As the warden exited the execution chamber at 1:09 a.m., Ledford began talking again, but the microphones had been cut off so his words weren't audible to witnesses.

Records from past executions show that the lethal drug generally starts flowing within a couple of minutes of the warden exiting the execution chamber. Ledford raised his head to look at his right arm right after the warden left and about a minute later appeared to speak to a guard to his right.

He then rested his head, closed his eyes and appeared to take several deep breaths before falling still within two or three minutes of the warden leaving the room.

Ledford told police he had gone to Johnston's home on Jan. 31, 1992, to ask for a ride to the grocery store. After the older man accused him of stealing and smacked him, Ledford pulled out a knife and stabbed Johnston to death, according to court filings. The pathologist who did the autopsy said Johnston suffered "one continuous or two slices to the neck" and bled to death.

After dragging Johnston's body to another part of Johnston's property and covering it up, Ledford went to Johnston's house with a knife and demanded money from Johnston's wife, according to court filings. He took money and four guns from the home, tied up Johnston's wife and left in Johnston's truck. He was arrested later that day.

Ledford told police he had a number of beers and smoked a couple joints in the hours before the killing.

Ledford's lawyers had asked the parole board to spare him, citing a rough childhood, substance abuse from an early age and his intellectual disability. After holding a hearing Monday, the board declined to grant clemency. Following its normal practice, the board did not give a reason for its denial.

Ledford's lawyers also tried to get the courts to stop his execution. The challenges were appealed all the way up to the U.S. Supreme Court, which rejected them shortly after 12:30 a.m. Wednesday.

Because of changes in brain chemistry caused by a drug Ledford has been taking for chronic nerve pain for more than a decade, there was a high risk that the pentobarbital Georgia planned to use to execute him would not render him unconscious and devoid of sensation or feeling, his lawyers wrote in a federal lawsuit filed Thursday. That would violate the prohibition against cruel and unusual punishment enshrined in the Eighth Amendment of the U.S. Constitution, the lawsuit said.

When challenging an execution method on those grounds, a U.S. Supreme Court precedent requires inmates to propose a known and available alternative. Ledford's lawyers, therefore, proposed that he be executed by firing squad, a method that is not allowed under Georgia law.

Ledford's lawyers also asked a state court judge to halt the execution because he was only 20 and his brain wasn't done developing when he killed Johnston. Just as juvenile offenders are considered less culpable and not the "worst of the worst" for whom the death penalty is reserved, the execution of those under 21 is also unconstitutional, Ledford's lawyers argue.

Ledford was the first inmate executed this year in Georgia. The state executed nine inmates last year, more than any other state and the most Georgia had executed in a single calendar year since the U.S. Supreme Court allowed the death penalty to resume 40 years ago.