TBH I wouldn't be surprised if he like mapped out the area of the city in CAD to figure out where the target would be visible from, where he could hide the bicycle, and what his route to the park would look like, or some shit like that. It's definitely not beyond the galaxy-brainedness of this kind of techbro (assuming it really was this guy, of course).

EDIT: NVM, I guess. I see the gun allegedly found on him at McDonald's is claimed to be a 3D print.