If the post above is correct, the active shooting had ended 3 to 4 hours previous and the shooter was dead by his own hand, having targeted one woman and one man instead of spraying out at many.
Secondly, what is the reason for breaking the doors down and making the employees lay on the floor 3-4 hours after the shooting stopped? It does seem that they were checking for any more possible shooters; but they apparently used protocols for an act of terrorism like the Kenya mall, where there had been specific threats made and chatter detected from terrorists prior to the event. But this one had all the usual earmarks of a love triangle gone bad.
I, too, have been in police training sessions, but not lately. A lot has changed; but with it, common sense seems to have gone out the window. I trust you are not in favor of the overmilitarization of the police, TSR; so I'm just clarifying my reasoning here.
Of course I'm not. I doubt that every small town police force needs an MRAP. The inner cities, which are potential riot zones, on the other hand . . .