My parents and relatives are totally against my relationship with boyfriend?

I think you just have to be careful. On the one hand you can see all the good things about your boyfriend, on the other your parents and relatives feel they have cause to be concerned. Is there anything that you're dismissing because you're forgiving him for it but that they think might rear its head again? You say he accidentally killed someone - he may have been perfectly innocent in that but the fact that he had a gun and was able to shoot someone with it would worry me. I think everyone has the potential to change and you shouldn't judge someone by their past, but it can't help but affect who they are as a person. Maybe your relatives are worried he might get involved with stuff like that again. I think the only thing you can do is to take things steadily with your boyfriend, don't rush into anything and really get to know him and his friends and make sure that you're completely happy with the kind of person he is in all aspects of his life before you do anything like move in with him or marry him or anything like that, especially as you have your daughter to consider. And try to involve him in things with your relatives. If he's as great as you believe he will prove that to them. It will take time which will be frustrating but just expect that it will, and hopefully after a while they will start to accept him. Best of luck.