here) in a case on prosecutorial misconduct from New Orleans called Smith v. Cain. The oral argument before the Supreme Court did not go well for the office of the prosecutor. (See here for a report.) This was the second case on prosecutorial misconduct out of the same office in two years. The previous one, Connick v. Thompson, has been described as "one of the most bitterly divided opinions of the Court in a criminal case in recent years."
One issue that divided the Court in that case was whether the evidence supported a finding that the misconduct was not an isolated incident. Evidently, in this particular case the Court thought the misconduct was enough to warrant reversal. The opinion does not really talk about misconduct as an ethical matter but simply concludes that the failure to disclose certain information to the defendant constituted a violation of the prosecutor's duty under Brady v. Maryland. As predicted by those who reported on the oral argument, the Court has decided to reverse the conviction and remand the case. The vote was 8 to 1. Justice Thomas was the only dissenter. The opinion, which is only four pages long, and the dissenting opinion are available here.
For analysis from the SCOTUS blog go here. To listen to the announcement of the decision of the court (and more) go here.