Washington (CNN) -- The man who allegedly walked into the conservative Family Research Council building in Washington last week and shot a staff member faces a possible 55 years in prison after his indictment Wednesday.
Floyd Lee Corkins II was indicted on three counts stemming from the August 15 shooting, including assault with intent to kill while armed. He also was charged with possession of a firearm during a crime of violence and interstate transportation of a firearm and ammunition.
The assault charge is a District of Columbia offense that carries a maximum 30-year sentence. The possession charge is another D.C. offense that carries a maximum of 15 years.
The federal firearms charge carries a 10-year maximum sentence.
Corkins is scheduled to be arraigned Friday.
Prosecutors say Corkins entered the council's Washington headquarters around 10:45 a.m. last Wednesday and encountered building manager Leo Johnson at the front door. They say Corkins pulled a handgun from his backpack and opened fire, striking Johnson in the arm.
Despite his wound, Johnson tackled Corkins and wrestled the gun away, prosecutors say.
At least one witness to the shooting heard Corkins say at the scene words to the effect of "I don't like your politics," according to an affidavit released last week by the government.
The affidavit says Corkins' parents told law enforcement their son "has strong opinions with respect to those he believes do not treat homosexuals in a fair manner."
The Family Research Council is a Christian group that focuses on family, anti-abortion issues, and religious liberties. It calls homosexuality harmful and unnatural and says marriage should be only between a man and a woman.
Wednesday's indictment does not provide any new details about the attack or a possible motive, but there have been questions about its relation to the recent controversy involving fast-food chain Chick-fil-A.
An earlier court document noted that Corkins had 15 Chick-fil-A sandwiches in his backpack when he was arrested. The agent who wrote the affidavit noted that a Chick-fil-A representative had "recently announced publicly his opposition to same-sex marriage."
Chick-fil-A President Dan Cathy said in an interview last month that he supports the "biblical definition of the family unit" as opposed to gay marriage. His comments to Baptist Press created a huge controversy across the country, with criticism and promised boycotts as well as a special "appreciation day" to show support.
The Family Research Council came out in support of Cathy.
At the time of the shooting, Corkins was living with his parents in Herndon, Virginia, and was volunteering at The DC Center, a community center for Washington's lesbian, gay, bisexual and transgender community.
"No matter the circumstances, we condemn such violence in the strongest terms possible," the center's executive director, David Mariner, said in a statement last week.
Corkins, who holds a master's degree in education and human development from George Mason University, appeared briefly in court last week. A judge appointed a federal public defender to represent him after Corkins said he has only about $300.