If you want to pry with a knife, I'd try the Boker Plus Cop Tool



http://www.boker.de/us/fixed-blade-knife/boker-plus/tactical-knife/02BO300.html

I don't know anything about breaking down doors. Even though I stayed at a Holiday Inn last night and have watched some Youtube videos about using various firemen tools to break down doors, I'll shut my mouth of ignorance and let the first responders here talk.