When police showed up to question John Thompson, he was worried that it was because he had sold drugs to an undercover cop.  When he realized they were investigating a murder, he could only laugh: “Shit, for real? Murder?”Thompson was insistent on his innocence, but New Orleans prosecutors wanted a conviction for a high-profile murder, and they were not scrupulous about how they got it. Thompson quickly found himself on death row. Eighteen years later, just weeks before Thompson was due to be executed, his lawyers discovered that a prosecutor had hidden exculpatory evidence from the defense. Thompson had been set up. This was a violation of the Brady Rule, established by the Supreme Court, in 1963, to ensure fair trials. Ultimately, he was exonerated of both crimes, but his attempts to get a settlement from the district attorney’s office—compensation for his time in prison—were thwarted. Though an appeals court had upheld a fourteen-million-dollar settlement, the Supreme Court reversed the decision, declining to punish the D.A. for failing to enforce the Court’s previous decision. Thompson’s case revealed fundamental imbalances that undermine the very notion of a fair trial.  Under the Brady Rule, prosecutors must share with the defense any evidence that could be favorable to the defendant.  But there is essentially no practical enforcement of this rule. In most states, prosecutors are the ones who hold the evidence and choose what to share, and disclosing exculpatory evidence makes their cases harder to win. We have absolutely no idea how many criminal trials are flawed by these violations.The staff writer Andrew Marantz, his wife, Sarah Lustbader, of the Fair Punishment Project, and the producer Katherine Wells reported on John Thompson’s story and its implications. They spoke with the late John Thompson (who died in 2017), with his lawyers, and with Harry Connick, Sr., the retired New Orleans D.A. who, despite having tried very hard to have Thompson killed, remains unrepentant. This episode contains explicit language and may not be suitable for children.