Death row inmate makes chilling remark in final words before execution for the murder of three people

A triple-murderer who spent more than three decades on death row made a chilling remark before he was executed on Wednesday (17 September).

David Joseph Pittman was given the ultimate punishment in 1991 after a jury convicted him of murdering his estranged wife's parents and younger sister a year prior.

He stabbed 21-year-old Bonnie Knowles seven times and cut her throat, according to USA Today, before fatally stabbing her mother Barbara, 50, and father Clarence, 60.

Pittman then set the family's home in Mulberry, Florida, on fire.

Investigators said the murders were motivated by his wife Marie Knowles filing for divorce, adding that Pittman had threatened to harm her loved ones multiple times.

The 63-year-old took the stand in his own defence when the case went to trial and claimed that he had been sleeping at his dad's home when the Knowles' were attacked.

However, Pittman's own father denied this when he was questioned in court, according to the Tampa Tribune.

David Joseph Pittman was 28-years-old when the murders of the Knowles family took place (Polk County Sheriff's Office)

Grady Judd, a sheriff in Polk County who responded to the crime scene 35 years ago, described the case as 'shocking', saying: "If ever there has been anyone who deserved the death penalty, its David Pittman."

He told the Lakeland Ledger that the killer was 'evil in the flesh' and 'vicious, mean and angry', explaining: "He was married to [Barbara and Clarence's] daughter and they were going through a breakup and so he decided he was just going to wipe out the whole family.

"David Pittman earned the death penalty. He was not given the death penalty. He earned it."

Pittman was put to death on Wednesday via lethal injection, making him the 12th death row inmate in Florida to be executed this year.

He used his final moments to make one last declaration of innocence, a statement from Republican Gov. Ron DeSantis' office said.

Before taking his last breaths, Pittman said: "I know you all came to watch an innocent man be murdered by the state of Florida.

"I am innocent. I didn't kill anybody. That's it."

Efforts by Pittman's legal team to halt his scheduled execution were rejected by the US Supreme Court earlier this week, despite attorneys arguing he was 'intellectually disabled'.

The killer insisted he was innocent during his final moments on Wednesday (Florida Department of Corrections)

But judges ruled that the murderer had 'methodically planned' the slayings of the Knowles family, saying: "In short, any claim that Pittman is intellectually disabled would run headlong into strong evidence of adaptive function."

Floridians for Alternatives to the Death Penalty, an advocacy group, also urged Florida's governor DeSantis to stop the execution before Pittman faced his fate.

The group claimed that the killer had 'grew up in extreme poverty, with a mother who gleefully admitted to whipping him with a belt from the time he was four years old'.

"Sometimes every day," the group said. "His family could not afford to continue the psychiatric treatment he needed.

"Violence, neglect, and hardship shaped his childhood long before the state ever called him 'defendant'."

DeSantis' spokesperson confirmed that Pittman's execution had been carried out without incident.

The 63-year-old drew several breaths after the deadly drugs were administered and then fell silent.

He had enjoyed steak, chicken and biscuits for his final meal, officials said.