body: If I see a "No Tresapssing" sign on a house door, but I hear screems for help from inside. The window was left open by mistake and I see a big guy beating an unarmed man and getting ready to kill him. 
  
  
  Would I be justified in front of the law to break in and shoot for the big guy's gun? (I am also putting the big guy's life in danger by shootin but he comes out unharmed).
  
  
  * Question: Assuming that my claims about the imminent murder having been about to take place prove to be correct, will the law, as it stands written, find me guilty of any of the 2 crimes that I have just comitted?
  
  
  The question is not about the morality or practicality of my actions. It is purely legal. 
  
  
  
title: Does preventing a murder justify breaking a "No Trespassing" law?