The armed man who walked into the Washington headquarters of the Family Research Council and reportedly shot a security guard Wednesday morning has been identified as Floyd Corkins, 28, of Virginia, NBC News reports.
Corkins was taken into custody by the FBI following the shooting and was being interviewed.
"We don't know enough yet about him ... or mentally what he's thinking," said James McJunkin, assistant director in charge of the FBI's Washington field office.
The guard, who was an employee of the FRC, was taken to a hospital in stable condition after being shot.
"Our first concern is with our colleague who was shot today," the group's president, Tony Perkins, said in a statement.
Republican presidential candidate Mitt Romney said in a statement that he was appalled by the shooting. "There is no place for such violence in our society," he said. "My prayers go out to the wounded security guard and his family, as well as all the people at the Family Research Council whose sense of security has been shattered by today's horrific events."
The Family Research Council advocates conservative positions on social issues and strongly opposes gay marriage and abortion. Fox News reports that Corkins posed as an intern and was carrying a Chick-fil-A bag with him during the attack.
Sources told Fox News that after guard took away his gun, the suspect said, "Don't shoot me, it was not about you, it was what this place stands for."
Perkins was an outspoken defender of Chick-fil-A President Dan Cathy's public stand against same-sex marriage, which made the fast-food chain a flashpoint in the nation's culture wars. The Cathy family foundation has funded the Family Research Council.
"He's taking a bold stand," Perkins said after Cathy's comments were reported. "Chick-fil-A is a Bible-based, Christian-based business who treats their employees well. They have been attacked in the past about their stand. But they refuse to budge on this matter, and I commend them for what they are doing."
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UPDATE: The Associated Press has learned that Corkins had been volunteering at a community center for gay, lesbian, bisexual and transgender people before his attack.
A law enforcement official has identified the suspect arrested in Wednesday's shooting as Floyd Corkins II of Herndon, Va. Investigators were interviewing his neighbors.
Another official says the shooter made a negative reference about the work of the Family Research Council before opening fire. The officials spoke anonymously because they were not authorized to discuss the ongoing investigation.
David Mariner is executive director of The DC Center for the LGBT Community. He says Corkins had been volunteering at the center for about the past 6 months. Mariner describes Corkins as "kind, gentle and unassuming."
This story is breaking and will be updated.
The Associated Press contributed to this report.