Apparently he went to Starbucks a few hours before the shooting. They have a surveillance photo of him, but he was wearing a mask. If he was dumb enough to do that, he might have been dumb enough to pay with a credit card. If this isn't the case and he keeps his mouth shut, he'll be awfully hard to find, especially if he doesn't live in NYC. We know he was a white male and that's about it.