A witness, a 56-year-old patient from Ontario who asked not to be named, told The Buffalo News she saw a man with a gun tucked behind his back walk into the restroom. When he came out, more of the gun was visible.

She said she didn't see him waving around the gun, but she was concerned enough to report this to a secretary in the office. An employee made the call to 911 and the practice locked its doors after the man briefly went outside.

Amherst police arrived about five minutes later. They approached the man and, the report said, took him down to the ground at gunpoint and handcuffed him.

Nowak says he was "violently grabbed, manhandled, thrown to the ground (and) assaulted."

"My understanding is they did not ask him any questions before they tackled him," said Peter P. Vasilion, Nowak's attorney.

In the claim, Nowak said police responded to a report of a "madman" brandishing and pointing a handgun and insists he was, in fact, sitting peacefully reading a book.

Nowak told the responding officers, according to the police report, that his handgun was concealed and in a holster at all times. Nowak told them his shirt might have ridden up, exposing the gun, the officers reported.