Omar Gonzalez, 42, appeared in court as Barack Obama’s spokesman said the president is “obviously concerned” by Friday’s stunning security breach.
Wearing an orange prison jumpsuit, Gonzalez stood impassively as US prosecutor David Mudd revealed that investigators had found the ammunition – “in boxes and magazines” – during a search of a car that was parked near the White House.
Also discovered were two hatchets and a machete, said Mudd, who made no mention of any firearms but described the accused as homeless, penniless and a flight risk.
Gonzalez was arrested on Friday after he evaded the outer layer of security around the US presidential residence, carrying a folding knife, and made it inside before being tackled.
A native of Texas who twice served in Iraq, he is charged with unlawfully entering a restricted building or grounds while carrying a deadly or dangerous weapon.
If convicted, he faces up to 10 years in prison.
Mudd revealed that Gonzalez had been free on bail following his arrest in July in the nearby state of Virginia on felony charges of eluding arrest and possession of a sawed-off shotgun.
On that occasion, he said, police found “numerous firearms” in Gonzalez’s vehicle, including a sniper rifle, plus a map tucked into a Bible with the White House and a Masonic temple circled.
Gonzalez was also stopped, but not arrested, outside the White House in August with a hatchet in his rear waist band. Police searched his car, but only found camping gear and two dogs.