Great point re: the hostel. This spurred another thought I had. I've stayed at a number of different hostels, and - generally - HI USA hostels are the biggest, the cleanest, the most 'corporate', and most well traveled hostels. Usually, they're a bit more expensive, and more stringent with their rules. It was an interesting choice for the shooter to stay there, vs. something like Jazz on Columbus Circle, which was much closer to where the murder took place. According to Google reviews, there's no 24/7 reception and it seems much more - lets say flexible - than HI USA. The flip side of that is if HI USA was busy, he could better blend in - but there's also a chance he would have been seen by fewer people at Jazz.