NEW : Obama , one drove up to Capitol Hill barricade with a rifle in his vehicle . NEW : Brock charged with possession of an unregistered firearm , ammunition . Police say he told them he had a delivery for President Alfred Brock . Man was arrested , transported to Capitol police headquarters for processing .
NEW : Alfred Brock , 64 drove up to Capitol barricade with a rifle in his vehicle . NEW : Brock charged with possession of an unregistered firearm , ammunition . Police say he told them he had a delivery for President Obama . Man was arrested , transported to Capitol Hill police headquarters for processing .