As long as the kids are minors, then the parents have to be held accountable for what they do. It doesn’t matter how “mature” the kids seem, they have no say in what they do and cannot be held accountable. There has to be a line drawn sometime for “parental responsibility” and “self responsibility” and the line is here. As parents, they have to watch the child and make sure that they don’t break any laws. I see nothing wrong with punishing the parents when the kid does something bad when it could have been prevented. (exception: kid has mental illness or something or sometime happened when the parents were not and could not be there (ie at school) – then it’s not the parent’s fault, and child should be punished/sent to an appropriate psychiatric place). In my opinion, too many parents these days are irresponsible and expect society to raise their children. I think dual punishment would be beneficial because it would not only teach the child, but it would force the parents to develop some sense of accountability.