But I have to say, in defense of this guy, I have personally experienced something like this. I believe it is his own fault for putting himself there but at the point where she is coming at him with a knife, I have been there.
When I was 16 my crazy stepmother came at me with a butcher knife. Before I even realized what had happened I had decked her. I never made a decision to hit her. I don’t recall even understanding there had been a threat. Literally, the sequence of events was, she had a knife, she was moving toward me, she was on the ground. I didn’t recall initially how she got there and was shocked that I had hit her. My conscious mind had literally not been an observer of the event. Literally.
“When I was 16 my crazy stepmother came at me with a butcher knife.”
You don’t have to tell me the answer to this question because you do have a right to reveal only what you want to reveal...but what did your father think about what happened?
Hitting your adult step-mom in self-defense when you were sixteen because she was coming at you with a knife is very different from an adult man grabbing a knife from his girlfriend and hacking her to death with it.
Also, at 16 you were a minor and your step-mother was an adult with authority over you in your home. This guy was the adult boyfriend who could have just walked out the door to his car and returned to his home.