There seems to have been a wide variety of motives from 6 January. Some seemed to have malice, others acted carelessly and disrespectfully, while others just seemed to be following the crowd. “Terrorism” has a definition and I don’t think it’s fair to call the whole crowd a group of domestic terrorists. The convictions they’ve gotten so far seem to validate that.
I’m not trying to armchair quarterback the Capitol police, but I think they could handle the situation much better if they had it to do over. Personally, I would feel awful if I opened fire on an “unauthorized tourist.” Once a situation like that gets out of control, though, it’s hard to restore order.