One things for sure is that it involved minors, which means any kind of lawsuit would instantly involve the parents, who i cant see taking it well that their familys corpses were tampered with, regardless of what the individual girls/boy say. However as much as we can emulate our culture/laws, it is a show, yeah there are "doesnt make sense moments" which can be boiled down to, example, the policeman is vain and an idiot that he just doesnt process it. However thats why the inspector is brought into the mix to fill those missing pieces on their background. The lids gonna blow up, the question is when.