New hampshire constitution
Part I – bill of rights
Article 17

In criminal prosecutions, the trial of facts, in the vicinity where they happened, is so essential to the security of the life, liberty and estate of the citizen, that no crime or offense ought to be tried in any other county or judicial district than that in which it is committed; except in any case in any particular county or judicial district, upon motion by the defendant, and after a finding by the court that a fair and impartial trial cannot be had where the offense may be committed, the court shall direct the trial to a county or judicial district in which a fair and impartial trial can be obtained.