The man, who authorities say shot an unarmed security guard while trying to get inside the conservative Family Research Council in August, has been indicted on new charges, including committing an act of terrorism, according to D.C.’s U.S. attorney’s office.

Prosecutors said the superceding grand jury indictment unsealed Wednesday against Floyd Lee Corkins II is the first time a suspect has been charged under the District’s Anti-Terrorism Act of 2002. Corkins could be sentenced to up to 30 years in prison on that charge alone.

The 28-year-old Corkins, who is from Herndon, Va., pleaded not guilty in August to a federal charge of transporting a firearm and ammunition across state lines and D.C. charges of assault with intent to kill while armed and possession of a firearm during a violent crime.

The suspect, who is being detained, was previously scheduled to appear in court for a status update on Friday, and a spokesman for the U.S. attorney’s office said Corkins will most likely be heard on the new counts as well.

Corkins’ attorney, David W. Bos with the Federal Public Defender’s Office, declined to comment on the new charges.

Thursday’s indictment charges Corkins with seven additional crimes — committing an act of terrorism while armed, attempted murder while armed, aggravated assault while armed, second-degree burglary while armed, and three counts of possession of a firearm during a crime of violence.

Authorities have said that on Aug. 15, Corkins walked into the lobby of the Family Research Council in the 800 block of G St., NW, near Gallery Place, and told the security guard, “I don’t like your politics.” Court documents say he then pulled a 9mm Sig Saur pistol from a backpack he had carried on Metrorail from East Falls Church.

D.C. police said Corkins shot the guard, Leonardo R. Johnson, 46, once in the arm before the guard was able to wrestle the gun away and subdue the suspect until officers arrived.

In his bag, court documents state that police found 50 rounds of ammunition and 15 sandwiches from Chick-fil-A restaurant. The head of the fast-food chain had spoken out against same-sex marriage, a stance embraced by the Family Research Council. Corkins had been volunteering at a U Street NW support center for the gay community.

Johnson has been called a hero. D.C. Police Chief Cathy L. Lanier and the head of the local FBI office visited his 72-year-old mother and 102-year-old grandmother in Southeast Washington.

On Monday, D.C. Mayor Vincent C. Gray presented Johnson with the first-ever medal of honor, saying in a statement that he “put his life on the line to wrestle a firearm away from an assailant and prevented what could have been a very tragic situation.”