The security force that guards the Capitol is a division of the Capitol Police. The uniforms of the Capitol Police are White, not Black.
The CIA is prohibited by law from operations within the United States. The agency who would respond to a Capitol incident would be the Capitol Police and the FBI.
The CIA has no jurisdiction to operate, much less hold people for questioning. This is a function of military intelligence. There is no agency full of CIA goons with badges that have authority to hold citizens for questioning, or in this case his knowledge of historical symbolism.
When Inoue Sato (CIA) showed her ID to police capitol Nuñez her name was spelled Inuoue instead of Inoue.