David Joseph Pittman, 63, who was convicted of killing three people in Mulberry in 1990, will be executed on Sept. 17, 2025, according to a death warrant signed Aug. 15 by Gov. Ron DeSantis.
Polk County Sheriff Graddy Judd, showing the 1990 mug shot of David Pittman and the family photo of his victim, speaks after David Pittman was executed for the 1990 triple murder at Florida State Prison in Raiford, FL on Wednesday, September 17, 2025. Pittman killed his wife’s parents and their daughter, set their house on fire then stole the daughter’s car and set it on fire. Law enforcement is angry it took 35 years to carry out the sentence. [Alan Youngblood/Gainesville Sun]

Florida has executed death row inmate David Joseph Pittman for the 1990 triple murder of his soon-to-be ex-wife's family, marking a record 12 executions in the state this year.

Pittman, 63, was executed by lethal injection on Wednesday, Sept. 17, for the murder of his ex's parents, Clarence and Barbara Knowles, and their 20-year-old daughter, Bonnie Knowles. The three were stabbed in the middle of the night and their house set on fire on May 15, 1990.

Pittman was pronounced dead at 6:12 p.m. ET.

”I know you all came to watch an innocent man be murdered by the State of Florida," Pittman said during his last words, according to the Associated Press. "I am innocent. I didn’t kill anybody. That’s it."

Pittman's execution is the 12th so far this year in Florida, a single-year record for the state, which has at least two more executions on the calendar. It's also the 31st execution in the nation, a 10-year high largely being driven by the high numbers in the Sunshine State.

Here's what you need to know about the crime, what Pittman's lawyers have been arguing and this year's high numbers.

What was David Jospeh Pittman convicted of?

In the dark of night on May 15, 1990, Pittman went to the home of Clarence and Barbara Knowles in Mulberry, roughly 40 miles east of Tampa.

Angry over his wife's divorce filing, prosecutors said at trial that Pittman first confronted her 20-year-old sister Bonnie, stabbing her seven times and cutting her throat before he fatally stabbed her 50-year-old mother and 60-year-old father and set the house on fire.

Except for his ex, Pittman "wiped out an entire family," prosecutor Hardy Pickard told jurors during the 1991 trial, according to an archived story in the Tampa Tribune.

Polk County Sheriff Grady Judd, a major in the agency's patrol division who responded to the scene of the crime in 1990, said "if ever there has been anyone who deserved the death penalty, it's David Pittman."

Speaking to the Lakeland Ledger, part of the USA TODAY Network, Judd said this week that the crime was shocking to the community and described Pittmas as "evil in the flesh."

Judd, who witnessed the execution, told reporters during a news conference afterward that Pittman "was evil then" and "never changed."

Pittman took the stand in his own defense during trial, telling jurors he was sleeping at his dad's home at the time of the murders − a claim his father denied when he testified, according to the Tampa Tribune.

Pittman was convicted of the murders and sentenced to death.

What were David Joseph Pittman's recent appeals?

Pittman's appellate attorneys most recently have been arguing that he is too intellectually disabled to be executed under the U.S. Constitution.

In a filing with the U.S. Supreme Court, they said Pittman had an IQ of about 70, was in classes for the mentally handicapped as a child, suffered brain damage, and that he was repeatedly denied the opportunity to present evidence of his disability in court.

"The State of Florida runs the imminent risk of executing an intellectually disabled person, contrary to theprovisions of the Eighth Amendment," Pittman's attorneys wrote.

The Florida Attorney General's Office argued that Pittman's claims were without merit.

"The record shows that Pittman methodically planned the murders," the state wrote in its Supreme Court filing. "He cut the telephone lines before entering the house in the middle of the night, stabbed and killed all three victims, and then set fire to the residence ... In short, any claim that Pittman is intellectually disabled would run headlong into strong evidence of adaptive function."

Pittman's attorneys have lost their arguments, most recently with the rejection of the U.S. Supreme Court on Tuesday.

When is the next execution?

Eleven more executions are scheduled in eight states by the end of the year, putting the U.S. on pace to put at least 42 inmates to death, a number that hasn't been seen since 2012. (There were 25 executions in the U.S. last year, while the all-time high number is 98 executions in 1999.)

The next two executions in the U.S. are scheduled on the same day next week.

On Thursday, Sept. 25, Alabama is set to execute Geoffrey West by the relatively new method of nitrogen gas for the 1997 murder of a mother during the robbery of the gas station where she worked.

Within the same hour of West's execution, Texas is set to execute Blaine Milam by lethal injection for the 2008 death of his girlfriend's 13-month-old baby. Milam was interviewed by accalimed German filmmaker Werner Herzog for a 2013 series called "On Death Row."

Amanda Lee Myers is a senior crime reporter who covers executions for USA TODAY. Follow her on X at @amandaleeusat.

This article originally appeared on USA TODAY: David Pittman killed his estranged wife's family in 1990. Florida just executed him.

Reporting by Amanda Lee Myers, USA TODAY / USA TODAY

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