Q: Is there a way to tune the alert type--intruder, shooter, medical, weather, etc?
A: No (but there's a good reason why)
We wanted the alert to be as simple and straightforward as possible to eliminate as much chaos and confusion as possible.
Lock down first, find out why second. System administrators can send out the Mayday alert which initiates a lock down and gets everyone to safety, then send out a notification explaining what is going on.