The security at the capitol was deliberately limited, probably to allow exactly this to happen and probably by the orders of Trump himself. The investigation over this will seal the deal on which higher ups get charged.
> They were minutes away from killing elected representatives.
For that to be true the people invading the capital would need to have intent to kill, weapons, and minutes access to those representatives. How many of those things are proven to be true?
All of those are true. They were there to "stop the steal" and were chanting "hang Mike Pence" and they had zip ties, pipe bombs, mace and more than likely plenty of guns. Only the elected representatives had time to evacuate, many of their staff were barricaded inside still. They had intent, weapons and access.