Over the weekend, Mississippi Attorney General Jim Hood announced that 51-year-old Albert Johnson had been arrested for the brutal rape and murder of two three-year-old girls in the 1990s. Johnson had been an early suspect in both cases, but despite the fact that the state had samples of his DNA on file for more than a decade, it never bothered to test it against the DNA found in the little girls.

That's because Mississippi District Attorney Forrest Allgood decided early on in both cases that he had his man, and little could convince him otherwise. One of those men is Kennedy Brewer, a mentally handicapped man who served more than a decade on Mississippi's Death Row, then served another five years even after DNA evidence had cleared him. Allgood insisted on retrying Brewer anyway, arguing that bite marks on the little girl's body matched Brewer's teeth.

Curiously, Allgood resisted testing the DNA from the crime scene against that of a man he had earlier convicted of an eerily similar crime—another rape and murder of a young girl in the same area. It now seems clear why Allgood resisted the test. As it turns out, the man he'd convicted for that crime, Levon Brooks, is innocent, too. Brooks had been sentenced to life in prison.

Hood is expected to announce on Thursday that Brewer has been completely exonerated. A similar announcement for Brooks could also come Thursday, or perhaps a few days after.

Had Allgood not fixated on Brooks after the first murder, he may have been able to prevent the second. Instead, we have two little girls dead, one man wrongly incarcerated for nearly two decades, and another who came perilously close to execution. And of course, there's also the matter of a two-time child rapist and murderer running free for 15 years.

In both cases, District Attorney Allgood asked Dr. Steven Hayne to perform the autopsies on the little girls. Dr. Hayne then called in his longtime collaborator Dr. Michael West to perform "the West phenomenon," a bit of quackery using fluorescent lights and yellow goggles that West says enables him to see bite marks no one else can spot. West was Allgood's star witness in both cases. In fact, after the DNA test exonerating Brewer in 2001, West's testimony was all Allgood had left, and was the reason he insisted on keeping Brewer in prison until late last year. In the Brewer case, the defense called an actual, board-certified medical examiner, who testified that the marks weren't from human teeth at all, but bug bites due to the body's exposure in a woods.

The weekend's events put a big, fat exclamation point on the corrupt, good ol' boy forensics system in Mississippi I reported on in a feature for reason last November.

My article focused mainly on Hayne, but Allgood and West also made appearances. Dr. Lloyd White, one of Mississipppi's last two official state medical examiners, left his position in disgust after trying and failing to rein in Dr. Hayne and the state's prosecutors and coroners. This passage seems particularly relevant:

White also cited a case in which he had performed an autopsy on a woman who’d been found dead in her bathtub. White concluded it wasn’t immediately possible to determine a cause of death; he needed to wait for the results of toxicology and microscopic tests. According to White’s letter, he soon received a phone call from Hayne, who told him the body had been taken to Hayne’s office for a second examination at the request of Forrest Allgood, the district attorney for Clay, Lowndes, Noxubee, and Oktibbeha counties. Although White was the state medical examiner at the time, he said the second autopsy was performed “surreptitiously, without my knowledge or permission.” Allgood already had a suspect he wanted to charge with the crime, White said, and “he was afraid my autopsy wouldn’t provide him with the evidence he needed.” (Allgood’s office did not respond to requests for an interview.)

According to White, Hayne told him he had concluded that the woman was strangled. White said Hayne then suggested it would be in White’s “best interest” to issue a report agreeing with him.

White's replacement also resigned in disgust after butting heads with Hayne, West, and the state's coroners and prosecutors. The office has been vacant since the mid-1990s, giving Hayne and rogue prosecutors like Allgood free reign.

This also isn't the first time an Allgood death penalty case has been overturned. In 1990, he convicted an 18-year-old mentally handicapped woman of killing her infant son. She was acquitted and released from death row after being granted a new trial due to problems with (surprise!) the conclusions drawn by the medical examiner Allgood recruited to perform the autopsy on the boy.

Since my article (and accompanying op-eds in the Wall Street Journal and the Jackson Clarion-Ledger) ran, very little has changed. That's too bad, because my sources in Mississippi tell me all the appropriate people down there were made aware of it, several times over.

Defense attorneys are more keen to Hayne, now, and are filing briefs challenging his status as an expert witness. But thus far, they've found little sympathy from the state's courts. Hayne is still doing autopsies in Mississippi, and judges are still letting him testify. Last November, the new judge in Cory Maye's case dismissed a brief in which Maye's lawyers asked that they be allowed to question Hayne's credentials. He said the case needed "closure." In another case, the court refused to grant an indigent defendant the funding to hire his own expert witness to review Dr. Hayne's autopsy. In both cases, attorneys cited my reporting on Hayne. My reporting on Hayne was also brought to the attention of Mississippi's State Supreme Court in the January 2007 case appeal of Tyler Edmonds. That case represented the first time the court had ever tossed out Dr. Hayne's testimony. Allgood was the prosecutor in that case, too.

So Mississippi's courts, lawmakers, and executive agencies are all well aware of the problem. They simply aren't interested in doing anything about it.

Attorney General Hood is doing the right thing in exonerating Brewer and (likely) Brooks. But it shouldn't stop there. It's time for Mississippi to conduct a thorough review of every case in which Dr. Hayne or Dr. West has ever testified. In fact, there are other medical examiners in the state whose work has been called into question, too. It wouldn't be the first time this has happened. Similar reviews have been conducted in West Virginia, Houston, and Oklahoma City after deficiencies and fraud in crime labs were exposed.

It's probably also time to start looking at possible criminal civil rights violations by Hayne, West, and Allgood. The state's entire medical examiner system is in need of a major overhaul. But right now, it's more important to undo the damage already done, and free the people Hayne and West may have already wrongfully sent to prison.