SALT LAKE CITY, Utah – A U.S. Airman 1st Class stationed at Hill Air Force Base has been charged with arson in connection to a police vehicle that was destroyed during the May 30 riot in downtown Salt Lake City, according to federal officials.

Officials said 22-year-old Larry Williams Jr, of West Haven, was arrested at his home Wednesday by the FBI and members of its Joint Terrorism Task Force, who were assisted by the Air Force Office of Special Investigations at HAFB.

“Since May 30, investigators and prosecutors have engaged in a determined investigation of those who were responsible for burning the police patrol car in downtown Salt Lake City,” U.S. Attorney John W. Huber said Wednesday. “Our intent has been to bring consequence to the lawlessness that we witnessed. While available video and photographs played a prominent role in the investigation, solid investigative efforts by agents and detectives made the difference in these arrests.”

Williams was the fifth person to be charged after a Salt Lake City police vehicle was overturned, vandalized and destroyed by demonstrators on May 30.

“During the riot, a Salt Lake City police officer, driving a police vehicle, became boxed-in and immobilized by surrounding protesters. Fearing for her safety, the officer fled from her patrol car,” federal officials said in a press release. “Her patrol vehicle was subsequently overturned, vandalized, looted and then set on fire. Video footage from the event shows individual rioters using fire and explosives to damage and destroy the police vehicle.”

Authorities said Williams was identified in video footage from May 30 next to Christopher Rojas, who has already been charged in connection to the incident.

“Rojas was observed holding a blue cigarette lighter in his hands while Williams held a white combustible fabric material, similar to a tablecloth or bedsheet,” according to federal officials. “Rojas used the cigarette lighter to ignite the fabric. Once the fabric began to burn, the complaint alleges Williams threw the material into the window of the overturned patrol car.”

They said Williams was dressed in a black Nike hoodie, black Nike sweatpants, black shoes and a black gas mask.

That gas mask was identified by investigators as an M50 Joint Service General Protective Mask, with an accompanying M61 canister that read “TRNG ONLY.”

Officials said Williams was issued an M50 mask as part of his training at HAFB in March. The readiness squadron at HAFB conducted a general inventory check of equipment on Aug. 13 and said documented serial numbers on the canister observed in photographs matched the lot number for one of the gas canisters assigned to Williams.

Federal officials said arson charges in the case are pending against Rojas, Jackson Patton, 26; Latroi Newbins, 28; and Lateesha Richards, 24, all of Salt Lake City, who were charged earlier.