Police are seeking to charge nine Proud Boys and three antifascist protesters for their role in the brawl that erupted on the Upper East Side on Friday, following an appearance by Proud Boys leader Gavin McInnes at the Metropolitan Republican Club.

During a briefing on Monday afternoon, NYPD Chief of Department Terence Monahan announced that the police department had enough evidence to charge the suspects with rioting and attempted assault—with the possibility of a full assault charge if victims come forward. Additional footage of the fight, which shows a masked protester tossing a bottle at a group of Proud Boys, was also released by the NYPD.

The briefing also included new details on how the encounter began. According to police, scooter cops were escorting the Proud Boys south on Park Avenue, when a group of protesters "flanked" them on 82nd Street. Video shows the two groups punching and kicking each other, with Proud Boys quickly outnumbering the masked protesters. Widely shared footage captured by journalists at the scene—which does not include the beginning of the altercation—showed dozens of Proud Boys kicking a protester on the ground, while yelling homophobic slurs.

Asked why the Strategic Response Officers who witnessed part of the fight did not make any arrests, NYPD Chief of Detectives Dermot Shea argued that it was not their responsibility. "We should not be scapegoating our cops who responded to a very chaotic scene," he said. "They're responsibility was to break this up. Other sectors responded to do the investigation, and were told not to get involved."

He noted that a 48-person police detail was at the scene, and overall their response was "pretty good."

"Three officers responded to a scene with around 20 people in there, as soon as they pulled up, everyone dispersed," he added. "People went in one direction and the other, so there was no one really to grab at that point. Our investigators are now looking through the scene and arrests will be made."

In a phone call with reporters on Monday, Governor Andrew Cuomo stressed that responsibility for the brawl fell to the Metropolitan Republican Club for inviting Gavin McInnes and his Proud Boy "thugs" to their clubhouse. "If you invite the Ku Klux Klan because the Republican party wants to demonstrate free speech, and the Klan marches down 5th Avenue, well don't be surprised if there is violence," he said. "What did you think was going to happen when you marched the Klan up 5th Avenue?"

A spokesperson for Mayor Bill de Blasio told Gothamist, "The Mayor’s pleased that the investigation is highly active and that it expects to yield more arrests."

Police are soliciting additional information on the suspects, and urge New Yorkers with information to call 800-577-TIPS.