I am so disgusted with humans: ignorant, irrationally, and just outright monsters.
First, whether or not the person was a pokemon or human being, it's not justified to take someone's life. If you believe the person is threatening, and you have a weapon that could potentially deter the person, why use deadly force? Why not simply shoot the person in an area of the body that decreases the possibility of death and also physically deters the person-- arm or leg, perhaps-- and leave the rest to the "justice" system?
A dead person can never speak, obviously; therefore, whether or not the young man is innocent, the world will never know. Who are you all to assume something when you all weren't even there? Just remember this, time and karma are two of the most beautiful and tragic things in life....