I haven't really been following, but I think maybe the guy who was killed was an American?
Jamal Khashoggi - Wikipedia
Saudi who was living in the US. Looking at his background, it seems his family was fairly highly placed and the government didn't like him running his mouth. They let him slide a couple of times but it looks like he pushed just a little too far.
Dictators don't fuck around. Not sure what he was anticipating. I guess he thought his ties would save him but they made him an example.