I think the sheer volume of tips probably overwhelmed resources and the justice department has to go through each one, verify whether or not it's true, whether it's provable, and whether they've got enough to win a case. Gathering that much info takes time and it'd be a terrible look to have a false ID. Hell, even someone who could stand trial and has a good chance of "not guilty" is amont the worst case scenarios.

I'm not sure how long that will take, but I think there's going to be very few people who went inside the capitol that somehow escape punishment.