Missouri death row inmate Marcellus Williams has been executed despite a prosecutor in the case and the victim’s family saying his life should be spared.

Williams, 55, had been convicted of the 1998 murder of Lisha Gayle, a former reporter for the St Louis Post-Dispatch.

His final words were “All praise be to Allah in every situation!!!” Williams’s Imam, Jalahii Kacem, visited him from 11am to 12.30pm on Tuesday. He and Williams’s son, Marcellus Williams Jr, were in the execution room when officials administered a lethal injection.

His final meal was served at 10.53am and included chicken wings and tater tots.

Williams’s death is the third execution for Missouri this year and the 15th in the nation. It was also among five executions that will take place in the US over just one week, starting last Friday with Freddie Owens in South Carolina. Travis Mullis, a Texas death row inmate, was executed for killing his infant son about an hour after Williams.

“Tonight, we all bear witness to Missouri’s grotesque exercise of state power,” Williams’s attorney, Tricia Rojo Bushnell, said in a statement. “Let it not be in vain. This should never happen, and we must not let it continue.”

More than a million petitions were delivered to Missouri Governor Mike Parson’s office requesting a stay of execution, the WEproject, a non-profit that campaigned against Williams’s death, has said.

High-profile figures, including British entrepreneur Richard Branson and US Representative Cori Bush, a Missouri Democrat, called on Parson to spare Williams’s life.

But both Parson and the state Supreme Court declined to intervene despite Williams’s clemency petition detailing how Gayle’s relatives wanted his sentence commuted to life without parole.

The inmate’s attorneys filed two last-minute requests with the US Supreme Court on Monday. Both of them were denied before he was put to death at 6.10pm CT.

Three justices — Ketanji Onyika Brown Jackson, Elena Kagan, Sonia Maria Sotomayor — dissented from the second request, which focused on new DNA evidence and claims from the prosecutor’s office that Williams may have been innocent.

Williams’s attorneys said DNA evidence on the knife used in the attack led back to an unknown male profile and did not match Williams. The court rejected a hearing about the claim on Saturday.

“There is no basis for a court to find that Williams is innocent, and no court has made such a finding,” St Louis County Circuit Judge Bruce Hilton wrote. “Williams is guilty of first-degree murder, and has been sentenced to death.”

Officials with the prosecutor’s office recently filed a motion to vacate his conviction.

A trial judge approved their motion but Missouri Attorney General Andrew Bailey contested the decision. The case was then sent back to the same trial judge who reversed his initial ruling.

During his murder trial, attorneys for Williams described him as “a caring and loving father.” His family members and friends had said that his execution would have “a significant effect on his family.”

Before leaving office, Missouri Governor Eric Greiten issued a stay of execution for Williams in 2017. He appointed a board of inquiry to look into the case and make a recommendation for clemency. Governor Parson dissolved the board and lifted the stay in 2023, after his election.

While describing Gayle’s murder during trial, prosecutors said Williams broke into her home, heard the shower running and found a large butcher knife. Gayle was stabbed 43 times when she came downstairs. Williams had stolen her purse and laptop, officials said.

It was the third time the Missouri Department of Corrections tried to put Williams to death. In 2015, the state Supreme Court called off his execution for more DNA testing. During the second attempt, Greiten granted his stay.

In an interview with KSDK, Williams Jr stated his intentions to stand by his father during his final moments.

“I’m going to stand there firm and show my dad he’s not alone,” he said.