I'd bet either just fines, a suspended sentence or if there is a custodial sentence that it will explicitly be delayed not to begin until Jan 21, 2029. Pretty sure there's something somewhere about not being able to use law enforcement powers to interfere with the ability of Congress/the Presidency/SCOTUS to do their appointed jobs. Otherwise the Chief of the Capitol Police would be the most powerful legislator in the country, by simply holding legislators he opposes for questioning any times there's an important vote.