A man who allegedly rammed his car into a Pittsburgh FBI office gate Wednesday was charged in federal court Thursday. He threw an American flag over the gate.

Donald Phillip Henson, 46, who allegedly rammed his car into a Pittsburgh FBI office gate Wednesday, was charged in federal court Thursday. File Photo by Bonnie Cash/UPI UPI

Sept. 18 (UPI) -- A man who allegedly rammed his car into a Pittsburgh FBI office gate was charged in federal court Thursday.

Prosecutors said Donald Phillip Henson, 46, of Penn Hills, Pa., nearly hit a security booth with an officer inside when he hit the gate. He grabbed an American flag from the car and threw it over the gate, then ran away on foot, officials said.

Police arrested him several hours later, and nobody suffered injuries.

Henson admitted to the FBI that "he rammed the Sidney Street Gate to 'make a statement,'" according to the affidavit.

Henson used the phrase, "sic semper tyrannis," which is Latin for "thus always to tyrants." "It is famously associated with the assassination of Abraham Lincoln by John Wilkes Booth, who is said to have shouted the phrase after shooting the president," according to the affidavit.

Henson faces charges of assault with a deadly weapon and damaging government property.

"We look at this as an act of terror, against the FBI," according to Special Agent in Charge Christopher Giordano.

"This was a targeted attack on this building," he added. "Thankfully, no one was hurt."

According to FBI officials, Henson recently visited the FBI field office and likely is a veteran with a history of mental illness.

"In scouring our indexes, we did find that he visited the field office a couple of weeks ago to make a complaint that didn't make a whole lot of sense," Giordano said.

He said Henson was later contacted by authorities to "let him know there wasn't a federal offense that we were able to charge."