NOTE: I'm not Dooming here. There will be justice. PAIN IS COMING.
Think about it. If a shoplifter is found filling his pockets in the store, security doesnt do anything until he steps outside the store. Only then can he be arrested. We've been told to be peaceful for a reason. We are fantasizing about a mass arrest at the 11th hour. This may not be part of the plan - just a heads up - this is bigger than any of have been counting on. Be prepared to let the enemy completely destroy themselves by allowing the coup to be completed.
It's not the craziest thing I've heard but I feel like it's on OP to bring the legal argument...
Biden's crimes are already committed. It's straight-forward accepting bribes and treason by allowing foreign government to operate through him. There's likely some murder, human trafficking, and sexual assault, etc. thrown in. Swearing him in doesn't make him any more of a criminal than he is right now.
I think the delay we're seeing is simply to have as many of these animals in the trap as possible.