Regular police do use those tools. SWAT is "special weapons and tactics", the heavy-equipment arm of the police used precisely in situations of such danger that normal levels of force are not appropriate (in this case, a situation where they believe there is a hostage and an active shooter).

If there is an active shooter and who is a competent marksman and has a perfectly ordinary hunting rifle, approaching them with non-lethal weapons is just giving them more opportunities to kill while they police try to incapacitate them.

Note the "pranker" didn't call in an event that would have resulted in normal police being dispatched (say, a domestic disturbance, or somesuch). They specifically called in a situation that demanded immediate application of potentially lethal force against an already active shooter.