Lots of folk should know better, but don't.
One could point out that if the child was brought up better the adult would know how to act and take responsibility.
That said I never had kids so do not know, when things go awry, whether the child was uncontrollable and the parents the victim; or the parents not doing a good parenting job which is the reason the adult messes up. Maybe it's some of one and the rest of the other.
Ultimately the parents have got away with it once the offspring is of an age to be held personally responsible, anyway. So if your question was about the parents being legally responsible, then no, they wash their hands of their offspring's behaviour by then.