I don't thing shyness would make someone violent for no reason. But for the sake of love i...

Depends on the person, it happens, my brother was like that. He was a really shy kid and then as a teenager he’d cover it up by being aggressive like telling people to eff off and getting in fights just because he wanted to avoid interactions with people, I think feeling like an outsider made him angry for no reason. He eventually made friends though and is a lot happier now.

I don't think that was shyness more like social anxiety, or anti social? since shyness tend to make people avoid as much interaction as possible especially get in fight with people.