Marcellus Williams was sentenced to death in 2001 for killing Felicia Gayle, a former newspaper reporter found stabbed to death in her home in St Louis, Missouri.
The 55-year-old's lawyers, Ms Gayle's family, the prosecution and the jurors who convicted him all have since come forward to say he may not be guilty.
At 6pm on September 25, 2024, local time, the state of Missouri executed him anyway.
The execution by lethal injection came after Missouri's Supreme Court and Missouri Governor Mike Parson denied appeals.
His last hope, the US Supreme Court, declined to intervene.
Williams's case had been championed by both the Innocence Project and the Midwest Innocence Project, groups that fight for people they believe have been wrongfully convicted.
One of his lawyers, the Midwest Innocence Project's Tricia Rojo Bushnell, told CNN the US legal system valued "finality over fairness".
"Tonight, Missouri will execute an innocent man," she said.
"They will do it even though the prosecutor doesn't want him to be executed, the jurors who sentenced him to death don't want him executed, and the victims themselves don't want him to be executed."
'His sense that something was wrong grew'
Ms Gayle was 42 years old when she was found dead in her kitchen in St Louis following a daytime burglary on August 11, 1998.
She had been stabbed and cut dozens of times.
Her purse, her husband's laptop and other items were also missing from the house.
Reporting by the St Louis Post-Dispatch, where Ms Gayle had previously worked, said at the time police had no official motive but had ruled out her husband, a radiologist.
Ms Gayle resigned from the paper in 1992 and went on to do volunteering, tutoring and advocacy work.
"She might have been diminutive in size, but she was never afraid to stand up for what she believed in," a former colleague told the outlet.
"She'd plant those little feet in those big, clunky shoes and stand her ground."
In a 63-page motion filed by prosecutor Wesley Bell last month, he described husband Daniel Picus's sense that something was wrong as he arrived at the couple's gated community home that night.
"As he walked to the house from the garage and up the stairs to the back door, he noticed the screen door was closed, but the back door was open," Mr Bell wrote.
"[This was] something he and his wife … would never do, as they always kept their doors closed and locked, even when they were inside.
"Upon opening the door, his sense that something was wrong grew.
"The kitchen was a 'mess'. The freezer door was open, and everything inside had been rummaged through. One of the kitchen drawers was open, and a cardboard knife cover was strewn across the floor.
"Concerned, Dr Picus called out for his wife. He did not get a response.
"As he walked out of the kitchen into the front hall, it became clear why."
The perpetrator, according to the Innocence Project, left behind "considerable forensic evidence", including fingerprints, footprints, and hair.
They also left behind the murder weapon, a knife from Ms Gayle's kitchen.
Key witnesses allegedly 'known fabricators'
In May 1999, Ms Gayle's family offered a reward of $US10,000 ($14,523) for anyone who could give them answers.
The investigation had gone cold until two people came forward and named Williams as the killer.
"[A] jail inmate named Henry Cole, a man with a lengthy record, claimed that Mr Williams confessed to him that he committed the murder while they were both locked up in jail," the Innocence Project wrote.
"Cole directed the police to Laura Asaro, a woman who had briefly dated Mr Williams and had an extensive record of her own.
"Both of these individuals were known fabricators; neither revealed any information that was not either included in media accounts about the case or already known to police."
The prosecution relied heavily on statements made by Asaro and Cole in the initial trial.
There was also, according to an application to the Supreme Court penned by lawyers on both sides, evidence of racial bias.
The trial prosecutor "used six of his nine peremptory strikes to eliminate black jurors, resulting in just one black member of the jury", they wrote.
"Mr Williams' conviction and death sentence were secured through a trial riddled with constitutional errors, racism, and bad faith, much of which only came to light recently."
Williams, who was already serving a 50-year sentence for an unrelated robbery, was sentenced to death on August 27, 2001.
Unknown male DNA found on the murder weapon
He was initially scheduled for execution in January 2015.
Just days before that, the Missouri Supreme Court granted a stay of execution to allow for more DNA testing.
The murder weapon, a knife left in Ms Gayle's body at the scene, had not been tested for DNA during the initial trial.
According to the last appeal, a "special master" was appointed in 2015 to test the handle of the weapon for DNA.
But, the appeal claimed, that the special master sent the case back to the state Supreme Court "without conducting a hearing or issuing findings".
"Three DNA experts independently reviewed the results of that test, however, and determined Mr Williams was excluded from the male DNA left behind on the murder weapon," it said.
"He was not the individual who wielded the knife.
"Nonetheless, the Supreme Court of Missouri set an execution date for August 22, 2017."
Just hours before that 2017 date, Williams was granted a second stay of execution by then-governor of Missouri, Eric Greitens.
A Board of Inquiry was convened to investigate the case.
Six years later, without issuing any recommendations, the inquiry board was dissolved by his successor, Governor Mike Parson.
Prosecutors said they received new DNA results on August 20, 2024.
[son interview] The unknown male DNA on the knife handle, they said, matched an assistant prosecuting lawyer and a former investigator for the prosecution.
"Both men had submitted affidavits claiming that they had handled the knife without gloves before trial, but until August 2024, there was no evidence to support their assertions," they wrote in their last appeal.
"These DNA results confirmed that their handling of the knife without gloves contaminated this critical piece of evidence."
Case 'languished for decades' as appeals continued
In August, Williams agreed to enter what is known as an Alford plea.
An Alford plea, also known as a "best-interests plea", allows an accused person to plead guilty while maintaining their innocence.
Instead of accepting guilt, the defendant accepts that there is sufficient evidence to find them guilty.
Williams consistently maintained his innocence.
[wesley bell tweet]A statement by Ms Bushnell at the time said the plea ensured "Mr Williams will remain alive as we continue to pursue new evidence".
Weeks later, a Missouri judge upheld Williams's conviction, and found there was "no basis for a court to find that Williams is innocent".
"Williams is guilty of first-degree murder and has been sentenced to death," Judge Bruce F Hilton wrote on September 12.
He said the concerns raised by Mr Bell had already been rejected by the Missouri Supreme Court.
He said other arguments, including evidence against Asaro and Cole and evidence suggesting Williams was not the source of bloody fingerprints and shoe prints at the scene, were just "repackaged arguments".
Ms Gayle's family also argued in favour of clemency, telling courts a sentence of life in prison was sufficient.
On Tuesday afternoon, the US Supreme Court concurred with Missouri officials.
Williams's final plea for clemency was denied.
Governor Parsons said in a statement he hoped the execution would give "finality to a case that [has] languished for decades, re-victimising Ms Gayle's family for decades".
"No jury nor court, including at the trial, appellate, and Supreme Court levels, have ever found merit in Mr Williams's innocence claims," he said.
"At the end of the day, his guilty verdict and sentence of capital punishment were upheld."
No members of the victim's family attended the execution, according to Missouri officials.
Williams's son and two of his lawyers were present.
Williams maintained his innocence to the end
One of Williams's lawyers said in a statement following the execution that his client had maintained his innocence until death.
"While he would readily admit to the wrongs he had done throughout his life, he never wavered in asserting his innocence of the crime for which he was put to death tonight," Larry Komp said.
"Although we are devastated and in disbelief over what the state has done to an innocent man, we are comforted that he left this world in peace."
Williams's case had attracted significant media attention during the appeals process.
About 100 people were protesting capital punishment as the execution got underway, according to a Missouri Department of Corrections spokesperson.
An Innocence Project petition asking for a stay of execution attracted more than 852,000 signatures.
Other petitions also garnered hundreds of thousands of signatures in the lead-up to the final plea for clemency.
According to his legal team, Williams was a devout Muslim, a prison imam and a poet.
[innocence project] Following his execution, Ms Bushnell shared on social media a poem written by Williams while in prison.
"Fireflies dancing in step with the light of the moon," it read in part.
"How strange it is to become aware of another's heartbeat but forget one's own – finally love."
