State v. Yanz, 50 A. 37 (Conn. 1901), was a case decided by the Supreme Court of Connecticut (then called the Connecticut Supreme Court of Errors) that held that a provocation defense that reduced a murder charge to one of manslaughter is still valid even in the presence of a reasonable mistake of fact. Specifically, in the case where a man reasonably believed his wife was committing adultery and kills her alleged paramour, even where that belief was mistaken, the provocation would be enough to reduce the charge from murder to manslaughter.