The wheels of justice grind slowly, especially for those sentenced to death who have been victims of miscarriages of justice. Marcellus Williams, who has been on Missouri’s death row since 2001 and is scheduled to be executed on September 24, knows this only too well.

Next week he will finally get the chance to prove his innocence.

Williams was convicted of the 1998 murder of former St. Louis Post-Dispatch reporter Felicia Gayle. Gayle, 42, was killed during a break-in at her home in an upscale St. Louis suburb. The crime was particularly gruesome: She was stabbed between 10 and 43 times with a butcher knife stolen from her kitchen.

In May 1999, Gayle’s family offered a $10,000 reward for information leading to an arrest and conviction in the case. Two police informants, both with criminal records, came forward and said that Marcellus Williams was the killer.

One of them testified that Williams confessed to him in prison. The other, who had previously been charged with solicitation, also testified that Williams confessed to her.

None of this was true. But it is a familiar pattern to anyone who has dealt with miscarriage of justice in capital cases.

This is a reminder that the American criminal justice system has a crippling problem with wrongful convictions, which is particularly acute in deaths involving informants. It is long past time to combat this epidemic and establish nationwide standards for the use of informant testimony when someone’s life is at stake.

We know that whistleblower testimony plays an outsized role in the wrongful conviction epidemic. As the Innocence Project notes, it is “one of the leading factors in wrongful convictions nationally, playing a role in nearly one in five of the 367 cases in which DNA-based exonerations have been conducted.”

In 2019, Pro Publica reported: “Since the U.S. Supreme Court upheld the constitutionality of the conviction in 1966, more than 140 people have been acquitted in murder cases involving the testimony of a prison informant.”

In that case, Hoffa v. United States, the court ruled that the use of informant testimony was constitutional as long as the defendant’s alleged statements were voluntary. Chief Justice Earl Warren dissented.

Warren warned that the use of informants poses “a serious threat to the integrity of the truth-finding process” in courts everywhere, noting that the motivations and backgrounds of many informants should always raise suspicion.

“No conviction,” Warren wrote, “should stand” if it was based solely on the testimony of informants. He warned that their use would result in “pollution … of the waters of justice.”

Warren was right. The Williams case is just the latest example of his wisdom.

The only two witnesses against him were promised leniency in their cases and a reward for their testimony. The Innocent Project reports that the investigation into Gayle’s murder “fell apart when a prison inmate named Henry Cole, a man with a long criminal record, claimed that Mr. Williams had confessed to the murder while they were both in prison. Cole pointed police to Laura Asaro, a woman who had briefly dated Mr. Williams and had a long criminal record of her own.”

“Both individuals,” the Innocent Project said, “were known liars; neither of them provided information that was not already included in media reports of the case or known to police. Their statements contradicted their own previous statements, each other’s statements, and the evidence at the crime scene, and none of the information they provided could be independently verified.”

And as journalist Madiba Dennie says: “Their testimony did not match the evidence from the crime scene. For example, they claimed that Marcellus was wearing gloves so he would not have to worry about fingerprints, when in reality there were someone else’s bloody fingerprints in the house.” None of the evidence from the crime scene incriminated Williams.

Dennie says: “The bloody footprints didn’t match his shoes. The fibers didn’t match his clothes. The hair didn’t match his body.”

Furthermore, during the trial, the prosecutor “intentionally excluded black persons from the jury by peremptorily rejecting six of seven black potential jurors. The fate of a black man accused of murdering a white woman was thus left to a jury consisting of eleven white persons and one black person.”

Fourteen years after Williams’ conviction, the Missouri Supreme Court ordered DNA testing of evidence from the crime scene, including the knife found in Ms. Gayle’s neck, her fingernails and hair found on her hand. Subsequently, three experts concluded that the DNA evidence showed that Williams could not have been the source of all the physical evidence at the crime scene.

In January of this year, Wesley Bell, the current St. Louis County District Attorney whose office had prosecuted Williams, finally came forward and acknowledged the miscarriage of justice in Williams’ case and asked the St. Louis County District Court to overturn Williams’ conviction.

As Bell told the court:

Based on a review of the evidence and additional investigation, the prosecutor concluded that: (1) new evidence suggests that Mr. Williams is in fact innocent; (2) Mr. Williams’ trial counsel was incompetent because he failed to investigate and present evidence to charge Henry Cole and Laura Asaro; 3) Mr. Williams’ trial counsel was incompetent because he failed to present mitigating circumstances during the sentencing phase; and (4) the prosecution improperly excluded qualified jurors during jury selection on racial grounds, in violation of Batson v. Kentucky. . . .

Based on the evidence before us and the ongoing investigation, the State Attorney believes it is the duty of this office to urge the court to correct this obvious injustice by requesting a hearing on the newly discovered evidence and the legality of Mr. Williams’ conviction. This request is all the more urgent because the Attorney General’s office has requested an execution date for Mr. Williams.

You would have thought that such an unusual admission of error by a prosecutor whose office secured the original conviction would be enough to secure Williams’ release. But not in Missouri.

There, the state’s Attorney General, Andrew Bailey, who has a long and bizarre history of refusing to release people from his state’s prisons even when their innocence has been proven, did the same in the Williams case. It took six months for the Missouri Supreme Court to deny Bailey’s request to block an evidentiary hearing, now set for Aug. 21, at which the district court will hear the overwhelming evidence of Williams’ innocence.

One can only hope that Marcellus Williams’ nightmare will end then. But whatever happens next week, it is time to institute reforms to stop the epidemic of wrongful convictions caused by reliance on informant testimony.

The Innocence Project proposes a number of long-overdue changes that should form the foundation of this reform effort. These include “Pretrial ‘reliability’ hearings to test the credibility of jailhouse informants. Robust tracking systems that detail the benefits provided to informants. Full disclosure of informants’ incentives and backgrounds to defendants. Clear instructions to the jury explaining the inherent unreliability of jailhouse witnesses. Expert testimony on typical informant practices and jailhouse culture.”

We owe it to Williams and to all future defendants charged with capital crimes based on whistleblower testimony to work to implement these proposals in every state that has the death penalty. This is the only way to escape the “quicksand” that Warren described as the starting point of these cases.