The sniper is using an ONLINE mapping service...Mapquest or YahooMaps whatever...he does his homework in advance...he may go to parks acting as tho he is "bird watching" with binoculars or a scope. He will appear "normal". He may even walk a dog or throw a frisbee and "scout" the parks.
He is MORE interested in the "Cat and mouse" game...in order of the events and the actions...
He enjoys "spying" through the scope MORE than the shooting
Shooting is the "final calling card" the activities UP to the shooting are ritualistic...MORE important to him than the actually killing/maiming of the people.
He is watching and listening to the news with the vim and vigor of a s^&t eating dog.
The activities LEADING to the actual shooting will RULE out fingerprints on a casing...he is very "ritualistic"...his preparations prior very very calculated...there will be NO prints and IF there are...they will NOT be his...could be a family members'...