When you are confronted with an armed suspect who raises a weapon at you, one moment's hesitation can mean that you're not going home that night. I don't care if it's a nun or a twelve year-old boy holding that weapon, you return fire. While it's not an example from domestic law enforcement, it's interesting to note that the Rangers who made it out of Mogadishu alive were the ones who didn't hesitate to shoot the young boys who were firing AK-47s at them. Now, there are several non-lethal alternatives to deadly force, but they require being in fairly close proximity to the suspect. (Rubber bullets, for example, will not travel as far as traditional rounds because of decreased mass and a necessarily poor ballistic coefficient.) But you NEVER use non-lethal force to meet lethal force - that's an invitation to getting officers killed. In the case at hand, the suspect exited the home and fired at the officers. Were they completely set up and in position? Were they ready to start negotiating...or were they still establishing the perimeter and discussing their next steps? In other words, did they return fire from a purely reflexive and reactive situation because the suspect pressed the issue? They may have had every intention of talking that man out, but when the suspect takes action that forces your hand, there's little you can do but protect your own life and end the confrontation immediately.