N.H. Const. pt. II, art. 38

The senate shall be a court, with full power and authority to hear, try, and determine, all impeachments made by the house of representatives against any officer or officers of the state, for bribery, corruption, malpractice or maladministration, in office; with full power to issue summons, or compulsory process, for convening witnesses before them: But previous to the trial of any such impeachment, the members of the senate shall respectively be sworn truly and impartially to try and determine the charge in question, according to evidence. And every officer, impeached for bribery, corruption, malpractice or maladministration in office, shall be served with an attested copy of the impeachment, and order of the senate thereon with such citation as the senate may direct, setting forth the time and place of their sitting to try the impeachment; which service shall be made by the sheriff, or such other sworn officer as the senate may appoint, at least fourteen days previous to the time of trial; and such citation being duly served and returned, the senate may proceed in the hearing of the impeachment, giving the person impeached, if he shall appear, full liberty of producing witnesses and proofs, and of making his defense, by himself and counsel, and may also, upon his refusing or neglecting to appear hear the proofs in support of the impeachment, and render judgment thereon, his nonappearance notwithstanding; and such judgment shall have the same force and effect as if the person impeached had appeared and pleaded in the trial.