A former Marine convicted of killing a 6-year-old girl more than four decades ago is set to be executed Thursday evening in Florida, which would be a record 16th death sentence carried out under Republican Gov. Ron DeSantis this year.

Barring a last-minute reprieve, Bryan Frederick Jennings, 66, is scheduled to receive a lethal injection at 6 p.m. at Florida State Prison near Starke. Jennings was convicted and sentenced to death twice for the 1979 murder in Brevard County, both of which were reversed on appeal. The final trial in 1986 resulted in a third death sentence.

The U.S. Supreme Court denied his final appeal Wednesday. Jennings` execution was one of three scheduled this week in the country, though in Oklahoma the governor spared the life of an inmate moments before he was to be put to death Thursday.

On Thursday, Jennings awoke at 4 a.m. and was later given a meal of a cheeseburger, fries and a soda, said Department of Corrections spokesman Jordan Kirkland. He added that Jennings had no visitors as he awaited the planned evening execution.

According to court records, Jennings was a 20-year-old on leave from the Marine Corps on May 11, 1979, when he took down the screen to the bedroom window of 6-year-old Rebecca Kunash while her parents were in another room.

Jennings abducted the girl, took her in his car to a canal and raped her, trial testimony showed. He then "swung her by her legs to the ground with such force that she fractured her skull," according to court records. The girl was then drowned in the canal, where her body was found later that day.

Jennings was arrested hours later on a traffic warrant, where investigators found he matched the description of a man seen near the Kunash home when the girl disappeared. Shoe prints found at the home matched those Jennings was wearing, his fingerprints were found on the girl`s windowsill, and his clothes and hair were wet.

Besides the murder conviction, Jennings also was convicted of kidnapping, sexual assault and burglary and drew life sentences for those crimes.

DeSantis has ordered more executions in a single year than any Florida governor since the death penalty was reinstated in the U.S. in 1976. The previous record was set in 2014 with eight executions. After Jennings, executions this year are scheduled Nov. 20 for Richard Barry Randolph and Dec. 9 for Mark Allen Geralds, which would bring the year`s total so far to 18.

Florida`s lethal injections are carried out with a sedative, a paralytic and a drug that stops the heart, according to the state Department of Corrections.

At a recent news conference, DeSantis explained the unprecedented number of executions by saying his goal is to bring justice to victim families who have waited decades for the death sentences to be carried out.

"Some of these crimes were committed in the `80s," DeSantis said. "Justice delayed is justice denied. I felt I owed it to them to make sure this ran very smoothly. If I honestly thought someone was innocent, I would not pull the trigger."

Jennings has filed numerous appeals in state and federal courts, most recently contending that he went months without a lawyer prior to DeSantis signing his death warrant in violation of his right to counsel. His current attorneys also say Jennings has improperly not had a clemency hearing since 1988.

An anti-capital punishment group, Floridians for Alternatives to the Death Penalty, sought U.S. Supreme Court review of the issues and what it called the politicization of the process.

"Florida`s death penalty system has become unrecognizable from the one the law promises," said Maria DeLiberato, legal and policy director for the group. "Bryan Jennings was left without a state court lawyer for years, denied a clemency review in this century, and then selected for execution because of favorable political timing."

A total of 41 people have died by court-ordered execution so far this year in the U.S., and at least 17, including Jennings, were scheduled to be put to death during the remainder of 2025 and next year, according to the Death Penalty Information Center.

Elsewhere in the U.S., Stephen Bryant is scheduled to die by firing squad on Friday in South Carolina.

Meanwhile, Oklahoma Gov. Kevin Stitt on Thursday commuted Tremane Wood`s death sentence to life in prison just before Wood was scheduled to receive a lethal injection for his role in the 2002 killing of farmworker Ronnie Wipf during an attempted robbery. Wood`s attorneys didn`t deny he participated in the robbery but maintained his brother Zjaiton - who died in prison in 2019 while serving life without parole - was the one who stabbed Wipf.

The story has been updated to correct the number of people executed this year in the U.S. to 41, from 40.