What does society owe someone who was wrongly convicted and sentenced to death row for 14 years? Nothing, the Supreme Court ruled today in a case that split the court’s conservative and liberal wing.

John Thompson was a month away from execution in New Orleans when his investigator found a prosecutor had deliberately withheld evidence in his armed robbery conviction, which led him not to testify in his own defense in a subsequent trial for murder, for which he was also convicted.

He sued the district attorney — Harry Connick Sr. — for failing to teach his employees that evidence that could lead to a person’s acquittal, needs to be turned over as well as the evidence that could lead to a person’s conviction. He won a $14 million judgment, which the Supreme Court overturned today because Connick wasn’t proven to have engaged in a pattern of violations.

As usual in cases like this, the court’s opinion, available here free, is the type of writing people pay money for in a bookstore, with justices tossing rhetorical bombs at one another.

Justice Clarence Thomas, who wrote the opinion, establishing that a district attorney is not responsible for the individual action of a rogue prosecutor.

The role of a prosecutor is to see that justice is done… “It is as much [a prosecutor’s] duty to refrain from improper methods calculated to produce a wrongful conviction as it is to use every legitimate means to bring about a just one.” Ibid. By their own admission, the prosecutors who tried Thompson’s armed robbery case failed to carry out that responsibility. But the only issue before us is whether Connick, as the policymaker for the district attorney’s office, was deliberately indifferent to the need to train the attorneys under his authority.

Justice Ruth Bader Ginsberg, in the unusual move of reading her dissent from the bench, painted a picture of a district attorney’s office hellbent on doing whatever it could to convict a person of murder, even crossing the ethical line:

The jury found Thompson guilty of first-degree murder.Having prevented Thompson from testifying that Freeman was the killer, the prosecution delivered its ultimate argument. Because Thompson was already serving a near-life sentence for attempted armed robbery, the prosecution urged, the only way to punish him for murder was to execute him. The strategy worked as planned; Thompson was sentenced to death.

That brought this from Justice Antonin Scalia, who suggested that the fault for the wrong convicted sat solely with one bad prosecuting attorney:

By now the reader has doubtless guessed the best-kept secret of this case: There was probably no Brady violation at all–except for (the prosecutor) Deegan’s (which, since it was a bad-faith, knowing violation, could not possibly be attributed to lack of training). The dissent surely knows this, which is why it leans heavily on the fact that Connick conceded that Brady was violated.

Back to you, Justice Ginsberg:

A District Attorney aware of his office’s high turnover rate, who recruits prosecutors fresh out of law school and promotes them rapidly through the ranks, bears responsibility for ensuring that on-the-job training takes place. In short, the buck stops with him.

It would be difficult to be Gerry Deegan today, reading the Supreme Court describe what a terrible prosecutor you were. But he died of cancer in 1994, reportedly acknowledging his misconduct on his deathbed.

Why didn’t Thompson just sue the prosecutor for a wrong conviction? Apparently, it’s against the law to do so (from October 2010):

Thompson was 22 when he was sent to death row. He’s 48 now, and formed an organization, Resurrection After Exoneration, to help others in a similar situation. In 2009, he said he’d hoped to use the millions he won to create a trade school.