I just read a longish column posted by a writer - Gurwinder Bhogal - who was in online and telephone communication with Luigi Mangione, the alleged shooter of health insurance CEO Brian Thompson. Bhogal self-describes as having Asperger's syndrome. For what it's worth, his perceptions might not be yours.
His insights into the mind of Mangione are interesting, they involve the extent to which modern individuals do or do not have "agency" or the ability to act, related to free will. Apparently, Mangione was concerned too many of us, including himself, have too little.
What may be involved is Mangione's supposed feelings that he was controlled, not by others, but by impersonal societal forces created to suppress or damp down agency, and his anger that this should be so. Viewed that way, shooting Thompson was a way to demonstrate the system didn't control his acts.
Bhogal does not in any way defend Mangione's supposed shooting. What he offers could be an explanation of motive. I put this link in the category of "It is interesting, but may be more speculative than factual." Hat tip to RealClearPolitics for the link.
N.B., The acronym NPC is used by Bhogal without definition. It is gamer slang, for a non-player character in an online game. NPCs perform in predictable ways, as programmed. Gamers think of them as "furniture," to borrow a derogatory term from the film Soylent Green.