The Justice Department says Attorney General Merrick Garland will not be prosecuted for contempt of Congress after refusing to turn over audio of President Joe Biden’s interview in his classified documents case because his actions “did not constitute a crime.”
The Sergeant-at-arms doesn’t need an actual jail in the Capitol itself. If they are empowered to hold someone, they can do it anywhere, even a hotel room. The Capitol Police also have a holding cell which could be used.
https://rollcall.com/2019/05/08/just-where-is-this-secret-house-jail-located/