The 30-year-old Fond du Lac woman was one of four women charged with being party to false imprisonment in the July 30 incident. Calumet County Circuit Judge Donald Poppy dismissed the charge against the victim's wife Monday.
CBS News is not naming the wife to protect her husband's identity as an alleged victim of sexual assault.
So far, two of the three other women charged have pleaded not guilty. One of them also is charged with fourth-degree sexual assault.
District Attorney Ken Kratz says he may appeal the decision or refile the charge with more evidence