In theory, during a trial, the judge decides on correct legal procedures and matters of legal interpretation. Juries decide the guilt or innocence of the defendant, based on the evidence. Jury nullification, in which a jury acquits a defendant even though guilt has been proven, can be seen throughout U.S. history. One professor encourages jurors to acquit black defendants in many cases to remedy past and current discrimination in the criminal justice system. The other professor argues that the need to convict a murderer and the need to protest the intolerability of official racism must remain separate if either need is to be met. He believes that promoting jury nullification as a legitimate way to right racial wrongs will only worsen the crime situation in black communities.