I’m not one to trust anything that comes out of the government, but if these guys were planning something like this and the government found out about it, it’s hardly reasonable to expect them to wait until after blood had been spilled.
If they were guilty of planning this, and after hearing an interview with his wife it sounds more likely, then they should have the book thrown at them. I still wonder how you can apply an “in the commission of an act of violence” into a thought crime. I worry for the precedent.