PORTLAND, Ore. (KOIN) — The U.S. Attorney’s Office charged a Portland man with possessing body armor during a September 4 demonstration outside the Portland Police Association building in North Portland.

Portland police declared an unlawful assembly after some people in the crowd allegedly threw rocks, bottles and cans at officers. Police arrested Maurice Monson, 30, after he refused to leave the roadway, according to the Multnomah County District Attorney’s Office, which is also pursuing charges against Monson.

At the time of his arrest, Monson was allegedly wearing a bullet proof vest, which is illegal due to a prior robbery conviction, according to authorities.

He initially faced charges of interfering with a peace officer, disorderly conduct, and felon in possession of body armor.

The first two charges were dropped, but now both the DA’s office and the U.S. Attorney’s Office appear to be pursuing the body armor charge.

Monson made his first appearance in federal court Tuesday and pleaded not guilty, according to the U.S. Attorney’s Office. His trial is scheduled to begin December 22.

KOIN 6 News reached out to Monson’s attorney for comment, but has not yet heard back.

At least 22 of the 27 people arrested in connection with the September 4 demonstration have had their charges dropped, according to court records.