In July 1999, Michael Grimm was involved in a heated altercation at a Queens nightclub where, according to witnesses, he brandished a gun, threatened a man's life, and "[carried] on like a madman." Grimm was investigated by the Department of Justice's Office of Professional Responsibility over the incident.

"'[Grimm] said to me, Thanks a lot man, he don't know who he's [expletive] with. Then he said something frightening. I'll [expletive] make him disappear where nobody will find him.'" -5/02/11

"According to one witness, 'Grimm was really aggressive and really violent. You know, you put on a badge and you really think you are above everybody else.'" -5/02/11

"'Grimm should have been arrested,' [a witness] told me. 'People that night were petrified.'" -5/02/11