I haven't seen the television news this morning, but the photos all over the media sure make this look like something from a movie rather than real life. (Stating the obvious, sorry.)
And as we're not used to seeing Islamic inspired killers looking clean cut and in a suit, I'm surprised that more "false flag" claims aren't already out there. The first to come up in Google is one on an odd looking site "Veteran's Today." A quick look at its home page indicates it posts lots of odd things, but I can't quite see the political lines its conspiracy stuff usually follows. Anyway, the link to their page seems to claim it is a Mossad hit, yet the headline is now reading that it was from "Turkish Intel" and a "false flag" by Erdogan (!)
And how is Trump going to comment? Via Twitter? We'll see. However he does, there's at least a 50% chance it'll be something gormless in either content or delivery.