On Tuesday, Missouri will execute Marcellus Williams, a death row inmate whose case has prompted several attempts to save his life amid questions about evidence presented at his 2001 murder trial and the actions of a defense attorney in the case.

Williams, 55, was convicted of first-degree murder and sentenced to death for the killing of Felicia “Lisha” Gayle, a journalist who was found stabbed to death in her St. Louis-area home in 1998.

He has maintained his innocence and his lawyers have filed a motion to have his sentence quashed, arguing that his DNA was not found on the murder weapon and that the jury trial was unfair.

On Monday, a day before Williams was to die by injection, his lawyers argued before the Missouri Supreme Court that his execution should be halted because the attorney for the prosecution in the 2001 case said during a recent hearing that he had removed a black man from the jury because of his race and that the prosecution had mishandled the murder weapon. The attorneys are asking the court to rule that those actions violated Williams’ rights or to let a lower court address those issues.

“The prosecutor in the Marcellus Williams case admitted under oath that he rejected a juror in part because of his race,” defense attorney Jonathan Potts said during Monday’s hearing.

Potts said the prosecutor struck a black man “partly because he was a young man with glasses” and that he looked like Williams. He said they were “like brothers.”

“He admitted that there was indeed a racial component, and that is unconstitutional,” he said.

The jury consisted of one black jury member.

Potts also argued that the prosecutor had mishandled the murder weapon in bad faith by holding it without gloves, which had caused the knife to become contaminated, which they argued could have been used to prove Williams’ innocence.

Deputy Attorney General Michael Spillane denied that the potential juror was eliminated because he was black, saying, “There is no clear compelling evidence here. There is no evidence at all.”

He also said that, based on the procedures at the time, the attorney had not mishandled the evidence by touching the knife without gloves after it had been tested.

During the trial, an inmate who shared a cell with Williams and an ex-girlfriend both said Williams confessed to them that he was responsible for the killing. His lawyers have said the two were seeking a reward.

In January, Wesley Bell, the top prosecutor for St. Louis County, filed a motion to vacate or set aside Williams’ conviction and sentence. This was done in part because DNA experts had concluded that Williams was not present in the DNA found on the murder weapon. This was because DNA tests, not yet available at the time of the trial, had concluded that Williams was not present in the DNA found on the murder weapon.

Before the hearing, tests showed the DNA matched that of members of the prosecution team from the original trial, who had handled the knife without gloves.

With that evidence reportedly tainted, Democrat Bell’s office and Williams’ lawyers reached a deal that spared Williams the death penalty in exchange for a life sentence without the possibility of parole.

A St. Louis County judge and Gayle’s family also approved the deal, but Attorney General Andrew Bailey, a Republican, opposed it and the state Supreme Court agreed.

Ultimately, a judge denied the motion to quash, a ruling Williams’ attorneys appealed to the Supreme Court during Monday’s hearing.

In addition to the appeal to the state Supreme Court, Williams’ attorneys have also filed an appeal with the U.S. Supreme Court and a pardon petition with Missouri Governor Mike Parson, a Republican.

The NAACP also asked Parson in a letter last week to stop the execution, saying it would be “a terrible miscarriage of justice and a continuation of the worst of Missouri’s past.”

“Taking the life of Marcellus Williams would be an unequivocal statement that when a white woman is murdered, a black man must die. And every black man will do so,” the letter read.

In 2017, the governor stayed Williams’ execution just hours before he was to be put to death after evidence showed he was not the source of the DNA found on the murder weapon. A previous execution date was also postponed in 2015.