Consider that idea that this shooter is a dissed LEO. Pissed with the cops and using this as an in your face sniping to disrespect them. One of the first was just across from a police station. The last was just over the head of a state trooper.
Now THERE'S a chilling thought !
Perhaps a frustrated SWAT sniper who got tired of waiting for the chance to show how well he can shoot people ?
Two things we know for certain: the shooter is EVIL and the shooter deserves to die.