The Cornell Legal Information Institute describes the facts of the case as follows:
On February 8, 2010, a magistrate judge held a hearing with the defendant, Anthony Davila, and his attorney. At the hearing, the judge encouraged Davila to plead guilty, and on May 11, 2010, Davila pled guilty to the charges. On appeal, Davila successfully argued that the judge’s encouragement constituted a violation of Federal Rules of Criminal Procedure (“FRCP”) 11(c)(1), which generally prohibits the judge from participating in plea-bargaining. The Supreme Court granted certiorari to determine whether any judicial participation in plea-bargaining, as opposed to “prejudicial” participation, mandates automatic reversal of a conviction. The United States argues that FRCP 11(h) requires the appellate court to review Rule 11 errors under the harmless error standard, while Davila counters that an 11(c)(1) error requires automatic reversal. Furthermore, the United States sees many 11(c)(1) violations as technical and harmless, while Davila views such violations as universally prejudicial, making the government’s role effectively redundant. Both Davila and the United States argue that a ruling for the other party will undermine the finality of guilty convictions secured by plea bargains.In its opinion yesterday, the Supreme Court reversed the lower court and held that even though the magistrate judge's participation in the plea negotiations was in "flagrant violation" of Rule 11(c)(1), "vacatur of the plea is not in order if the record shows no prejudice to Davila’s decision to plead guilty."
The Court's full opinion is available here.