What to Know Police say they've arrested one of the people they'd been looking for in the brawl last week involving Proud Boys and protesters

Video released by the NYPD shows the start of the brawl on the Upper East Side, where far-right leader Gavin McInnis was speaking

The Proud Boys is identified as a hate group by the Southern Poverty Law Center

Police say they've made an arrest in the brawl last week involving members of the far-right group known as the Proud Boys and demonstrators protesting the its controversial alt-right leader Gavin McInnis.

Geoffrey Young, 38, of New City in Rockland, faces charges of riot and attempted assault in the Oct. 12 brawl. It's not immediately clear if he has an attorney who could comment on the charges.

Young and other supporters of the Proud Boys allegedly squared off with people protesting McInnis at an event on the Upper East Side where he was speaking. Punches and kicks were thrown, with many falling onto the sidewalk.

Surveillance video released by the NYPD shows how the fight unfolded: a person with a mask seen on the left of the video —believed to be an alleged anti-fascist activist — throws a bottle. Suddenly, people on the right, believed to be supporters of the right-wing Proud Boys Group rush in, throwing punches..

“When uniform scooters arrive on the scene, they immediately disperse and you can hear people in the video yelling, 'Stop! Stop!'" NYPD Chief of Detectives Dermont F. Shea said"

The violence spilled onto other corners on the Upper East Side – all of it happening after McGinnis, leader of the Proud Boys, identified as a hate group by the Southern Poverty Law Center, was invited to speak at the Metropolitan Republican Club.

The male-only Proud Boys describe themselves as "western chauvinists."

No serious injuries were reported in the aftermath of the massive fight. Three others have been arrested in the fight and authorities are still looking to question many others in connection to the brawl. The NYPD says both sides have been uncooperative.

The Republican Club had been vandalized ahead of Friday's speech by McInnes, who is also a co-founder of Vice Media. Statewide Republican officials said the damage included smashed windows, a spray-painted door and a keypad lock covered in glue. A note left at the scene claimed that the damage was "just the beginning."

Gov. Andrew Cuomo has asked the FBI to launch an investigation into the violence.