The U.S. Park Police have issued an arrest warrant for a suspect who may pose a threat to President Obama.
The U.S. Secret Service believes Oscar Ortega-Hernandez, 21, may have fired shots near the White House last Friday.
An additional round of ammunition was also found outside the building on Tuesday.
Authorities say Ortega-Hernandez is mentally ill, but he also has an extensive criminal record ranging from domestic violence to drug charges.
He may have deadly intentions toward the president.
"This is a man who discharged a rifle in downtown D.C. I think that speaks volumes. We're going to need to speak with him to find out just what he was thinking," said Sgt. David Schlosser, spokesman for the U.S. Park Police.
The Secret Service revealed that a bullet fired last Friday on the Washington Mall struck an exterior window of the White House and was stopped by ballistic glass.
After the shooting, authorities found a car containing an AK-47 rifle and empty shell casings.
The suspect fled, but police linked the car to Ortega-Hernandez. The man is said to be fixated with the White House.
Authorities believe he's been visiting the Washington Mall for weeks, and they're concerned about what he might do next.
Before the shooting, local police detained him at an abandoned house.
"They handcuffed him. They had him on the grass and I guess they let him go," local resident Cindi Shore, who witnessed the incident, said.
President Obama is on a diplomatic trip to Australia, but the authorities are taking no chances. They're not certain whether Ortega-Hernandez is capable of launching a sophisticated attack against the White House or the president.