But the sniper may be on a different tack, I think he spends 90% of his study time on his escape route, and "who" he shoots is only incidental to his very refined escape plans. So he may very well be using a weapon which aids in escape, which is why I would tell the LEOs NOT to rule out a rifle caliber pistol which could fit under the seat of a GEO Metro or in a daypack or briefcase or baby stroller.
The choice of weapon then becomes a balance of risk. Will he be able to kill more people before getting caught given the concealability of a TC, or the more fatalistic approach of planning on a fire fight and opting for a semi/full auto.
With that question in mind, the TC is probably the best choice. This person may have good reason to believe he will never get caught. This is a problem.
Two very sobering thoughts come from this.
1). We should expect these types of shootings to begin nation wide and continue until each shooter is rounded up. Ie. It wont stop.
2). Peace in the US will not exist as long as Islam is an organized movement. We could be forced to face the "endgame" by something as simple as a few hundred snipers.
America may have to rediscover it's tradition of grim resolve.