Earlier this year, I wrote about a sprawling prosecutorial scandal in Orange County, California, involving a long-standing program of secret jailhouse snitches that had tainted prosecutions in cases almost too numerous to count. This story has only continued to worsen. One of the prosecutors at the heart of the case simply packed up and left California last month, and just this week the news emerged that Orange County District Attorney Tony Rackauckas had been told that his office might have a jailhouse informant problem all the way back to 1999, a full 16 years before the current allegations about the misuse of jailhouse snitches had surfaced.

The problem with a scandal on this order of magnitude isn’t just that it reflects a fundamental flaw in the justice system. The problem is that, as a purely practical matter, there is simply no easy way to correct it. In Orange County, some convictions have been tossed, others have been stalled, and a call for a Justice Department investigation has gone unheeded. Even years after cases like this come to light, undoing or redoing wrongful convictions proves almost impossible to achieve, especially when the state believes someone else should be cleaning up the mess.

Perhaps the most dramatic example of a massive scandal that cannot seem to be reversed involves Annie Dookhan, a chemist who worked at a Massachusetts state lab drug analysis unit. Dookhan was sentenced in 2013 to at least three years in prison, after pleading guilty in 2012 to having falsified thousands of drug tests. Among her extracurricular crime lab activities, Dookhan failed to properly test drug samples before declaring them positive, mixed up samples to create positive tests, forged signatures, and lied about her own credentials. Over her nine-year career, Dookhan tested about 60,000 samples involved in roughly 34,000 criminal cases. Three years later, the state of Massachusetts still can’t figure out how to repair the damage she wrought almost single-handedly.

By the close of 2014, despite the fact that there were between 20,000-40,000 so-called “Dookhan defendants” (depending on whether you accept the state’s numbers or the American Civil Liberties Union’s), fewer than 1,200 had filed for postconviction relief.* Many of them were sentenced under plea agreements rather than at trial, and they feared that a re-examination of their cases could potentially lead to even longer sentences. So the ACLU of Massachusetts stepped in last spring, filing Bridgeman v. DA of Suffolk County to ensure that no defendants would face harsher penalties if they challenged their Dookhan evidence.

In May, the Supreme Judicial Court of Massachusetts unanimously ordered that each of the defendants whose guilty pleas were based on Dookhan’s evidence could seek new trials without facing added charges or stiffer sentences. The state court stopped short of ordering each of the convictions vacated—the remedy sought by the ACLU. But the court effectively capped any defendant’s sentence to what it would have been under the original plea agreement.

The state argues that most of those Dookhan defendants were surely guilty of something, and the cost of vacating all of their convictions would be chaos. There has already been one reported homicide attributed to a freed Dookhan defendant. In 2012, Donta Hood had his conviction thrown out because Dookhan had tested his drug evidence and testified against him at trial. He was released from prison two years early and charged with murder a year later.

Of course, there are also an awful lot of folks whose convictions were predicated on a massive fraud. Many of them don’t even know this, and most cannot afford to hire attorneys to reopen their cases. Even if they have already served their sentences, the collateral impact of having drug convictions infects every part of their lives. Who is responsible for fixing that?

In Massachusetts it doesn’t even end there. Only a few months after Dookhan’s conviction, it was discovered that another Massachusetts crime lab worker, Sonja Farak, who was addicted to drugs, not only stole her supply from the evidence room but also tampered with samples and performed tests under the influence, thus tainting as many as 10,000 or more prosecutions. Records show Farak used cocaine, crack, or methamphetamines daily or almost daily while she was at work, as well as ketamine, MDMA, ecstasy, phentermine, amphetamines, LSD, and marijuana. Farak pleaded guilty and served 18 months behind bars.

But in April, Massachusetts’ highest court found that state law enforcement officials had never fully investigated the scope of Farak’s wrongdoing, retesting only 10 samples of her work. And based on new discoveries by defense lawyers, the extent of Farak’s drug abuse now appears far greater than was initially alleged. Officials at the time of Farak’s arrest claimed she had tampered with the drugs she tested beginning only in July 2012, and only after she had tested each sample. That is now in serious doubt.

Retired Superior Court Judge Peter A. Velis was appointed by Attorney General Maura Healey to examine the Farak case after the April ruling, and he is tasked with determining the real scope of wrongdoing from the Farak case. Among other things, Velis’ investigation is now looking into allegations by several defense lawyers that the attorney general’s office under then–Attorney General Martha Coakley deliberately withheld evidence that the Farak scandal was much worse than it let on.

Two defense attorneys, Luke Ryan and Rebecca Jacobstein, subpoenaed Farak’s medical records to see if their clients had been affected and found that her drug use and theft had extended all the way back to 2004, eight full years before the state claimed it began. They contend that this new evidence warrants a review of all 29,000 samples Farak claimed to have tested during her career. They also claim the government concealed this “smoking gun” evidence from defense attorneys.

Documents revealing Farak’s addiction were kept from defense lawyers for more than a year and a half, despite multiple requests. Once they were finally able to inspect these documents, defense attorneys obtained court orders requiring Farak’s clinicians to produce copies of their treatment records.* Judge C. Jeffrey Kinder ruled last June that Farak’s treatment records should be unsealed because they contain information that could be important to others whose cases involved evidence tainted by Farak. Among the newly revealed records are these notes from a local Amherst, Massachusetts, therapist who treated Farak in 2009 and 2010: “She obtains the drugs from her job at the state drug lab, by taking portions of samples that have come in to be tested.”

Despite the defense counsel’s requests for “any third party who may have been aware of Farak’s evidence tampering” in late 2013, the prosecutor’s office had claimed “there is no reason to believe that a third party had knowledge of Farak’s alleged malfeasance prior to her arrest.”

A prosecutor from the attorney general’s office called the evidence defense attorneys were seeking “irrelevant to any case other than Farak’s,” dismissing requests for evidence that Farak’s drug use had been long-standing as “merely a fishing expedition.”

Ryan learned that one of his clients had been convicted with evidence Farak had produced on a day she was using drugs. But as Ryan has pointed out, relief comes case by case, and many who have been convicted using tainted evidence never even know they are eligible for relief.

As Ryan told the Daily Hampshire Gazette, the Farak defendants may prove even harder to track down and help than those who were tainted by Dookhan, which would be a nightmare: Almost three years after Dookhan’s arrest, only 8,700 of those defendants have been assigned lawyers, Ryan said. “And in this case, we don’t even have a list.”

Despite the ongoing scandal, the district attorneys take the position that it is not their responsibility to help identify Dookhan or Farak defendants. They lack the budgets or resources to do so, and—as they have argued in oral argument in the Bridgeman case—prosecutors have no special duty to notify defendants that their convictions might have been obtained with evidence that was falsified by government employees.

So the question remains: When a crime lab screws up, whose responsibility is it to clean up the mess?

Laura Fernandez of Yale Law School studies prosecutorial misconduct. Asked about who should be repairing the damage from the two Massachusetts crime lab scandals, she observes that:

Everyone knows that if you make a mess, you have to pay for it or clean it up. Companies know this, drivers know this—even kids know it. What most people don’t realize is that even in cases where prosecutors’ misconduct or negligence results in gross violations of due process, colossal disruptions of the criminal justice system, or grave threats to public safety, prosecutors remain essentially immune from any real consequences. When the people who wield the most power in the criminal justice system are also the least accountable, constitutional crises like those unfolding in Orange County and Massachusetts are almost inevitable.

Over the past decade, crime lab scandals have plagued at least 20 states, as well as the FBI. We know that one of the unintended consequences of the war on drugs has been a rush to prosecute and convict and that crime labs have not operated with sufficient independence from prosecutors’ offices in many instances. Their mistakes ruin lives. Years of deliberate falsification have ruined thousands of lives. We also know that there remains almost no reason for a prosecutor’s office to admit error and that the cost of fixing those errors can become prohibitive. So what do we do when a scandal infects hundreds or thousands of prosecutions? If Massachusetts is any indication, even three years later, we still don’t do all that much.

Correction, Oct. 30, 2015: Due to a production error, this article originally misidentified the American Civil Liberties Union as the American Civil Liberty Union. This article also originally incorrectly misstated that Sonja Farak’s medical records were hidden from defense counsel. Other documents were kept from counsel leading to discovery of the medical records.