It really depends on the extent the social media and ISIS propaganda influenced them, in addition to any other underlying conditions.
In case you're keeping score, the Muslims represent 1% of US population, but people "who happen to be Muslim" kill up to 94% of all people killed in terror attacks in the US (not counting the deadliest terror attack of all time). It depends a bit on what you define as a terror attack of course, but the result is clear: the social media and ISIS et.al. propaganda enlarge the problem by at least one order of magnitude and possibly up to two.
So, um ... 90-99% of the problem is one big similarity. What you're discussing are minor variations of the problem.
McHrozni