We picked this specialty because we want to help people, and we are very good at making decisions immediately — life-or-death decisions.

So our mind-set at that time is: How are we going to deal with this circumstance from an injury standpoint, a systematic standpoint and a smooth-running machine? That’s in our brain at the beginning. We try to set our emotions apart from that immediately, but we’re humans and we really care about the people we take care of. We have to fight the battle of depersonalization all the time, but when you’re trying to save somebody’s life, you can’t be emotional.

Dr. Guillamondegui: It’s a tragedy for the people involved, the community at large. For us, it’s a Tuesday. We’re going to do what we have to do whether it’s two patients or 20.

The police say that the gunmen at the church and at the school used handguns, but that the suspect at Waffle House used an AR-15, a rifle. How do the weapons change the nature of the injuries you’re treating?

Dr. Miller: Trajectory equals injury. It’s much easier to know the trajectory of a single gunshot wound where you have an entrance and an exit and you can figure out the path. When somebody comes in with multiple gunshot wounds based on someone with an automatic rifle shooting them eight times, you’ve got to figure out which bullet is going to kill them, and that can be a lot more challenging.