If the Unibomber was engaged in an attempt to recruit thousands of followers to participate in waging a terrorist war against western democracies...no!
If you don’t ask the person who commits an act about why he did it, how are you going to know the reasoning behind it? Will you just assign him a reason and decide that’s it, regardless of what he says?
Seems to me the best way to find out a perp’s motive is to, um, ask the perp.