or they have absolutely no idea and hes on a freighter heading back to costa rica/dubai/etc.
the whole 'we dont want to tip our hand so we arent going to identify him' larp is what you say when you cant really stand up and say 'we have absolutely nothing and btw yes you can murder a healthcare CEO in the heart of manhattan at point blank range in broad daylight and just caper off into the sunset'.
on twitter we were joking about how the shooter was id'd as this main character crypto guy and the next day they posted his picture on the news as the assassin. so yeah this is going poorly from an investigative perspective.