Based on what little I know, it sounds to me that Officer English did the absolute right thing in this situation. It is sad that a human has been killed… but protection services, public or otherwise, will have to use deadly force from time-to-time to protect innocent human life.
This is the type of thing that police should be doing: protecting people from malum in se.
To those who would question the decision to fire the fatal shot right after a hostage negotiator has arrived I would say this: situations change very quickly. Were I in Officer English’s shoes… my priority would not be trying to resolve the situation without the deceased getting hurt. My priority would be trying to resolve the situation without the person the deceased was threatening to kill getting hurt. If that means killing the offender while a team of hostage negotiators gather outside, enter the room, or beg me to have a chance to talk the offender down, so be it. I would have fired too.
I will snoop around and see if I can find a copy of the actual Attorney General report.