Polk County triple murderer executed after spending 3 decades on death row

MULBERRY, Fla. - Florida carried out its 12th execution of 2025 on Wednesday evening, when 63-year-old David Pittman was put to death by lethal injection.

Pittman was pronounced dead at 6:12 p.m. at the Florida State Prison in Starke under a death warrant signed by Governor Ron DeSantis. 

The backstory:

Pittman was convicted of murdering his ex-wife's sister, Bonnie Knowles, along with her parents, Clarence and Barbara Knowles, in 1990. Prosecutors said Pittman stabbed the three victims to death, then set their home on fire in an act of revenge against his wife, who was filing for divorce.

The killings took place in Polk County and Pittman has spent more than three decades on death row.

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Pittman’s defense team mounted two recent appeals — one before the Florida Supreme Court and another before the U.S. Supreme Court — arguing that he is intellectually disabled and therefore ineligible for execution under the Eighth Amendment, which bans cruel and unusual punishment.

Both appeals were denied, clearing the way for his execution.

What they're saying:

His ex-wife, Marie, attended the execution with other family members. Polk County Sheriff Grady Judd, who was also present, said she told him afterward: "Now I can move on."

"He stayed evil to the end," Judd said. "He earned the death penalty three times and today justice occurred."

By the numbers:

Pittman’s execution marks the 12th in Florida this year, already setting a record for the state. DeSantis has signed off on 14 executions in total for 2025.

"I appreciate Governor DeSantis looking out for the victims," Judd said on the number of executions in the state. "You know, I only saw one gurney in this room. I'll buy him 11 more, so we can do this 12 at a time. If they can figure out a way to do 12 at a time, because there's 250 people who viciously and violently murdered people in the state of Florida on death row. And quite frankly, that's too many. We need to get with it."

Among those awaiting execution is Samuel Smithers, a Hillsborough County man convicted of killing two women, Christy Cowan and Denise Roach, in 1996. Smithers, nicknamed the "Deacon of Death," has challenged his conviction and sentence at least four times over the past 26 years. His execution is scheduled for October 14.

Smithers will become the second Hillsborough County killer executed this year. In May, Glen Rogers was put to death for the 1995 murder of Tampa woman Tina Cribbs.