US Criminal Law/Defenses/Prosecutorial misconduct
Prosecutorial misconduct can come in various forms, but it most commonly arises in a few ways. First, a prosecutor's sidebar statements during trial can be prosecutorial misconduct. These may be comments about the defendant, his attorney, a witness, or the judge. These comments can result in a mistrial with Pre-Judice (barring reprosecution), assuming the trial court concludes that they were made for the purpose of inciting the motion for mistrial. Other times, they will just result in a mistrial without prejudice. Second, a prosecutor's failure to turn over material, exculpatory evidence to the defense, in dereliction of his duties under Brady v. Maryland, 373 U.S. 83 (1963). This is a type of prosecutorial misconduct which may be raised at virtually any time, even post-conviction, as it is a constitutional error of great magnitude. If the defendant can prove the prosecutor failed to turn over Brady material, he will typically receive a new trial. Third, a prosecutor's selective prosecution of a person or group of people may be misconduct. Also, if a prosecutor increases the punishment or charges based on the defendant's exercise of his rights (to jury trial, of appeal, etc.), this may (under certain circumstances) be misconduct.