And they may not ‘remember’ because they know they were in meetings, groups, clusters of co-conspirators guilty as sin. I forget how many hung around Dallas that day and how many had started to disburse out of Dallas before the shooting.
I am reminded of the the fact that John Wilkes Booth thought he would be a hero. It's easy in a way to manipulate weak minded people, highly impulsive people, emotional people.
When I was at a job where we could use the net. I watched a lot of videos, You tube, Netflix (like the documentaries etc). I never posted about it here as no one at the time wanted to hear about it.
One video featured a former intelligence agent. He described how easy it is to find people to do the dirty work. Find a misfit, with few friends if any. Befriend him. Spend time, mentor etc. You become this misfits whole world. You can then turn him into anything you want. It does not work with everyone, but there is a certain percentage of people it will work on.
You don't sit there and tell them you are going to kill XXX, you plant the seed. The guy is trying to get your love and approval. He will do it and think it was his idea. Then think he's going to be applauded. He gets killed or jailed and you disappear. He never knows what hit him. It really is that simple.