A 57-year-old father of three who claims his knee was shattered by overly aggressive police officers during the G-20 summit last year filed a federal lawsuit against the city of Pittsburgh on Monday in what is likely to be the first of many similar claims.

Frank Beal, of Point Breeze, says he was assaulted by an officer from the Harrisburg Police Department, who was working for the city during the summit.

Before going to Oakland the night of Sept. 24, Mr. Beal had been in Bloomfield and Lawrenceville earlier in the day observing the action, said Sam Hens-Greco, Mr. Beal's attorney.

But about 11:30 that night, Mr. Beal was standing at Thackeray and Fifth avenues in Oakland when, he said, he was attacked, without being given any prior warning to disperse.

"[An] unknown police officer yelled at the plaintiff to 'move,' " according to the lawsuit. "The plaintiff asked, 'How far do you want me to move?' "

The unknown officer responded "to the next traffic light."

But as Mr. Beal began walking away, he said, Officer Edward V. Grynkewicz III, along with four unidentified officers he believes are from the Harrisburg area, grabbed him from behind, forced him to the ground and sprayed him with pepper spray.

He claims his face hit the concrete sidewalk and his right knee was repeatedly struck with a police baton, causing a fractured patella.

"At no time did the plaintiff struggle with the police or attempt to flee," the lawsuit said. "Rather, at the time of his assault by the defendants, plaintiff was in the process of peacefully complying with a police directive."

Prior to the incident, the lawsuit said, there were no problems in that area of Oakland.

"I can't even say he got swept up in the action, because there was no action to be swept up in," Mr. Hens-Greco said.

Although Mr. Beal, a processor for a local bank, received summonses for resisting arrest and failure to disperse, the charges were withdrawn by the district attorney's office on Jan. 20.

Among the claims listed in the lawsuit are allegations that the city failed to properly train its G-20 security forces on crowd control and management techniques, along with claims of excessive force, unreasonable search and seizure and a violation of Mr. Beal's First Amendment rights to free speech and freedom of assembly.

City solicitor Dan Regan said his office was reviewing the complaint and could not comment.

Looking for more from the Post-Gazette? Join PG+, our members-only web site. You'll get exclusive sports content, opinion, financial information, discounts from retailers and restaurants, and more. Our introduction to PG+ gives you all the details.