Ok I will answer your question and see if you understand. When this happened in season 11 I was the one person who thought the way it went was really bad. First of all, Carter who wanted to kill Emma, just released her to fight MC with a knife.
If someone had a knife on the neck of my daughter to kill her, I'd kill him first If I could to protect her. That means, If the criminal didn't let her go (like Carter did) and I am skilled enough to pull out my gun and shoot him right in the head. That is what me as a father would do.
But that is not what happened. He released Emma. What I would do then was either runaway (with my daughter and her mother) or stay and fight while my daugther would runaway with her mother. Or even if I wanted to end his life, I'd pull out my gun as soon as he released her and shoot him, probably multiple times, if I wasn't in the right state of mind. But I would take responsability for what I'd done. I wouldn't think that the girl's mother should see me as a good guy, when I knew exactly what I was doing and I killed the guy intentionally. See the difference?
The problem in this discussion right now is people thinking that she should just be ok, fully trust him now and then open her legs to MC.
Now lets go back to what really happened in this VN. Carter left go of Emma, MC Fought him bravely with his bare hands, disarmed the man, immobilized him, then just killed the guy. Do you see the difference here? It was not something that happened so fast that he had no time to think. If he went to the trouble of doing all that, why kill Carter then, specially in front of Emma? Her life wasn't in danger that it would be categorized as self defense anymore.
He decided to take the man's life. At that point he should face the justice according to his actions and not expect that Charlotte would see it as an amazing action. You guys complaining about how she reacted, and saying she overreacted, or she not trusting him is a bunch of crap is the only thing I am going against right now lol.
For MC that might be his breakfast of every morning. But it is not how Charlotte sees or feel about it and that is 200% understandable.
If someone hurts your child and you wanna kill them for it. That is your decision. Just don't expect others to see it as ok or legal because it is not, unless it is self defense.