They made perfect sense once, once the motives become clear. And that did not take long in any of those case you mentioned.
Shooting up a McDonalds and killing lots of people because you were fired? Makes no sense.
Similar to other events. We put together a narrative later, to help us “make sense” of it.
And, it takes time. It took plenty of time in the other instances. It certainly was not done in a couple of days.
The idea that we do not have an obvious motive yet, and we should, is a structure of our minds, not the mass killers.
He may have deliberately *not* left a manifesto or note, simply to create this effect. He seems to have been a pretty good manipulator.
What do you mean? Of course it makes sense and it happens all the time. I could show ya countless work place shootings where the shooter definitely has a motive, either real or falsely perceived but nevertheless, the shooter still believed he had a motive and more often than not, they make their motives known.