WATCH: 'Sovereign citizen' battles cops during 'full-frontal assault' on GA courthouse

Authorities released surveillance video from the “full-frontal” assault on a Georgia courthouse earlier this year by a sovereign citizen.

Dennis Roland Marx drove his SUV onto the front plaza June 6 at the Forsyth County Courthouse, where he parked on a sidewalk at the base of the steps with his driver’s side door open.

He exchanged gunfire with Deputy Daniel Rush, who had been outside the courthouse when Marx pulled onto the courthouse plaza.

Rush was shot in the leg during the shootout, and he was later treated for a broken tibia and fibula.

The 48-year-old Marx was shot and fatally wounded by the 30-year veteran during the shootout.

“It would be a guess to think how many lives he saved had he not engaged him right there,” said Sheriff Duane Piper. “Mr. Marx’s intention was to get inside that front door and to take hostages.”

Video posted online by PoliceOne shows Marx, who was armed with an AR-15 and wearing a gas mask and bulletproof vest, remain in the vehicle for about two minutes before tossing tear-gas canisters out of the SUV.

The vehicle is enveloped in a thick cloud of chemical irritant, but the wind quickly disperses the gas, and Marx lobs smoke grenades outside.

SWAT vehicles arrived several minutes later, and his body is carried out of the SUV.

Marx wore an explosive device strapped to his body, and police also found zip-ties, bombs that could be clipped to hostages, and two handguns.

Investigators said evidence showed Marx planned the attack carefully, and a checklist at his home showed items found inside his SUV.

Additional explosives were also found at his home, which was booby-trapped with still more explosives.

"He came in there with the purpose of occupying the courthouse,” Piper said. “It was a full-frontal assault.”

Marx was previously arrested on multiple felony charges, including weapons possession.

He also filed a 2013 civil rights complaint against the Forsyth County Sheriff's Office.

He has been due in court the day of the attack to plead out on marijuana distribution and firearms possession charges.

His attorney said she withdrew from his case the day before because he was unsatisfied with her negotiating abilities, and she asked him to undergo a psychological examination – which he refused.

The attorney also said Marx made “veiled threats” against her during their time together.

Watch video from the incident posted online by PoliceOne: