The video on liveleak is good, unedited quality. It should serve as an example of how these incidents should be handled.
After multiple viewings, you can stop and study the scope of the response. There are multiple parishioners, all armed, covering the point of attack from multiple angles. Nobody is rushed or disoriented in their armed response.
Well done fellow citizens! You have our prayers and best wishes as you contend with the aftermath of this tragedy.
Sorry for the loss and suffering of your fellow members of your congregation.