Case Name: Livingston against Kiersted and Heermance
Court: New York Supreme Court of Judicature
Jurisdiction: New York
Decision Date: 1813-08
Citations: 10 Johns. 362
Docket Number: 
Parties: Livingston against Kiersted and Heermance.
Judges: 
Reporter: Johnson's Reports
Volume: 10
Pages: 366–366

Head Matter:
Livingston against Kiersted and Heermance.
ALBANY,
August, 1813.
If anon compos ranged °r¡ne* Sncompetont Tf a witness is
IN ERROR, on certiorari, from a justice’s court. K. and H, sued L. on the 29th oí April, 1811, before a justice, and declared ^ him for unlawfully raising and keeping up a mill-dam conto the lands of the plaintiffs, whereby they were overflowed, &c. The defendant pleaded, 1. Not guilty; 2. The statute of limitations; 3. A justification under deeds from Kiersted, and" Everadus Bogardus, the owner of the lands, by virtue of which he had a right to keep up the dam, provided the dam 7vas 7iot raised, and averred that the dam had not been raised, at least, since the plaintiffs claimed the land. There was a trial by jury, on the 17th of May. The plaintiffs proved that the dam had been raised by. one V. 12 years ago, and that it overflowed the land of the plaintiffs, and that they had exercised acts of ownership on the land. The justice ruled that it was competent for the plaintiffs to show by parol proof, that they were themselves in possession of the land overflowed: and the plaintiffs thereupon called a witness. The defendant offered to prove that the witness offered was 7i07i co7npos, and that he had been for some time deranged; but the evidence was overruled by the justice. And the jury found a verdict for the plaintiffs below, and assessed their damages to 10 dollars, on which the justice gave judgment.

Opinion:
Per Curiam.
The exclusion of testimony to prove that a witness offered on the part of the plaintiffs was non. co7npos, by reason of his mental derangement, was erroneous. If it could have been shown to the court below that the witness was deranged, or had not the ordinary understanding, he must have been excluded as incompetent. Idiots, lunatics and mad7iien are not competent witnesses, and this must be shown to the court by proof, like any other charge of incompetency. The defendant was prevented, from showing this, and the witness was admitted. As we cannot tell what weight the jury may have given to his testimony, the judgment must, for that cause, and without considering the other points raised, be reversed.
.Judgment reversed»