The state of Mississippi executed 55-year-old inmate Marcellus Williams on Tuesday night, despite calls from both the state attorney general’s office and the victim’s family to halt his execution.

Williams, who was convicted of murdering Felicia Gayle in 1998, was put to death by lethal injection Tuesday at 6:10 p.m. CT, the Missouri Department of Corrections said. He has maintained his innocence throughout his 23 years in prison.

The execution came after a series of last-minute attempts to save Williams’ life. His lawyers filed a series of appeals, citing bias in jury selection and the lack of DNA evidence on the murder weapon. The U.S. Supreme Court, the last body that could have halted Williams’ execution, denied his lawyers’ latest request on Tuesday, with all three liberal justices dissenting.

The decision by the high court’s right-wing majority came after the Missouri Supreme Court and Republican Gov. Michael Parson also rejected requests for a stay of execution.

“Mr. Williams has exhausted all due process and legal remedies, including more than 15 hearings attempting to prove his innocence and overturn his conviction. No jury or court, including at the trial, appellate and Supreme Court levels, has ever found Mr. Williams’ claims of innocence valid,” Parson said in a statement.

Since January, St. Louis District Attorney Wesley Bell has tried to block Williams’ execution, arguing that prosecutors had previously made “constitutional errors” that contributed to Williams’ murder conviction. New evidence suggested Williams was “intrinsically innocent,” he said.

“Marcellus Williams should be alive today. There were multiple points in the timeline where decisions could have been made that would have spared him the death penalty,” Bell wrote in a statement after the execution. “When there is even a shadow of a doubt of his innocence, the death penalty should never be an option. This outcome did not serve the interests of justice.”

Felicia Gayle’s family also opposed Williams’ execution.

Williams, a devout Muslim, said in closing: “Praise be to Allah in every situation!” The father of two was described by his lawyers as “extraordinary”. He spent much of his time in prison studying Islam and writing poetry. He was known to many as “Khaliifah”, which means “leader” in Arabic.

One of Williams’ attorneys, Larry Komp, said in a statement that his death will result in an “erosion of public confidence in the system.”

“Transparency is a hallmark of democracy, and it is sorely lacking here,” Komp wrote. “For us, Khaliifah was an inspiration. We aspire to his level of faith, his integrity, and his total dedication to the people in his life. He was fiercely protective of the people he loved, and he loved them deeply.”

Lawyers, politicians and criminal rights activists across the country condemned the decision to carry out the execution. Reps. Cori Bush, D-Mo., and Alexandria Ocasio-Cortez, D-N.Y., called for the abolition of the death penalty after Williams’ execution.

“Governor Mike Parson has shamefully allowed an innocent man to be executed tonight. We must abolish this flawed, racist, inhumane practice once and for all. Rest in peace, Marcellus Williams,” Bush wrote.

Former Georgia Congresswoman Renitta Shannon wrote that the Supreme Court’s decision not to block Williams’ execution is indicative of larger systemic problems within the U.S. criminal justice system.

“What does it say about our justice system when the U.S. Supreme Court refuses to stop an execution even when the prosecutor who originally handled the case files a brief supporting a stay and overturning the entire conviction?” she wrote in a post on X. “I sincerely hope the conversation about #MarcellusWilliams is far from over. I hope this execution politically haunts every elected official in #Missouri and beyond who supported it or didn’t care enough to speak up about it.”

According to the NAACP, Williams’ death is reminiscent of the Jim Crow era and racist terrorism.

“Tonight, Missouri lynched another innocent black man,” the civil rights group said in a post on X. “Governor Parson had a responsibility to save this innocent life, and he failed to do so. The NAACP was founded in 1909 in response to the barbaric lynchings of black people in America — we were founded precisely because of people like Governor Parson who commit violence against innocent black people. We will hold Governor Parson accountable. When DNA evidence proves innocence, the death penalty is not justice — it is murder.”

Williams’ death is the third execution in Missouri this year.