Rape..was this the right thing to say?

Ok so my boyfriends friend got raped.

He says shes like a little sister to him and hes really mad at the person who did it.

The girl went to the police and did tests and things. and I guess the police is going to take care of it.
The girl knows...

who did it.

My boyfriend is really mad and says he wants to kill him.

So I told him ..there is nothing he can really do. Hurting the boy who did that to her will only start more problems for him. And the only thing he should be doing is helping his friend get through this situation.\

was that the right thing to say? I mean I dont know what else I could have said, I never been through anything like this.

I dont know what to do to make him feel better here.

Thank you for all your help.

Ummm well that is the logical thing to say. But a lot of times guys go crazy when they are upset about something and they cant do anything about it. Just remember 2 b patient with him and dont freak out on him if he like beats the guy up or something.