molestations in his neighborhood.

 Imagine that you are a member of a jury. The jury is hearing a child molestation case in which the defendant is accused of a series of molestations in his neighborhood. You have been advised by the judge not to discuss the case with anyone outside the courtroom, and especially not with anyone on either side of the case. Going down in the elevator after the fourth day of the trial, you happen to ride with the prosecutor in the case. He tells you that the man has a previous arrest for child molestation, but that it has not been allowed in by the judge, as being too prejudicial for the jury. You were fairly sure that the guy was guilty before, but now you definitely believe he is guilty. You also know that if you tell the judge what you have heard, it will probably result in a mistrial. What would you do? What should happen to the prosecutor?