Church security for pacifists

This isn't a joke but a legitimate issue. Christians want to balance "turning the other cheek" with protecting the weak and vulnerable. After the recent Colorado shootings some of us supported the church security guard using bullets and some of us were appalled and thought volunteers should absorb all bullets. One force is active and one is passive. What if a combined response was possible? Is there something that could actively hinder a shooter while also capable of taking on some lead? There is something that police departments are already using. And they are expensive. Guns are cheap. Humans lives are priceless. What about trained guard dogs? They are trained to subdue identified threats non-lethally, some wear body armor, and if they die to save a life it would be a worthwhile trade. There are plenty of retired, cheaper police dogs for smaller churches.