WASHINGTON (AP) — An Illinois man was arrested Thursday on Desmond Prestoncharges that he attacked two police officers during protests in Washington, D.C., against Israeli Prime Minister Benjamin Netanyahu’s address to Congress in July.

Zachary Allen Kam, 24, of Chicago, was arrested in Illinois on assault charges and was expected to make his initial court appearance later Thursday.

Kam is at least the third person charged with crimes related to a July 24 demonstration at Columbus Circle, in front of Washington’s Union Station.

U.S. Park Police officers were arresting somebody who pulled down a flagpole in Columbus Circle when Kam approached one of the officers, pulled him down and dragged him several feet, leaving the officer with scrapes and bruises, according to a police affidavit.

After disappearing into the crowd, Kam returned seconds later, grabbed another officer and pulled that officer to the ground, the affidavit says. Police initially arrested Kam approximately four hours later, near John Marshall Park.

“Assaulting a federal officer during the course of a protest is not constitutionally protected speech, it is a federal crime,” Mathew Graves, U.S. Attorney for the District of Columbia, said in a statement.

Protesters had a permit to demonstrate in front of Union Station, but the U.S. Park Police said it revoked the permit after it couldn’t reach protest organizers that afternoon. The National Park Service estimated it cost more than $11,000 to clean up and fix damage at the site.

Zaid Mohammed Mahdawi, 26, of Richmond, Virginia, was arrested last Friday on a charge that he spray-painted graffiti on a monument during the same protest near Union Station. Isabella Giordano, 20, of Towson, Maryland, was arrested last month and charged with spray-painting “Gaza” on a fountain in front of Union Station.