How did they ingrate back into society without getting in trouble?

I suppose there is still the gap from when they get rescued to adulthood that we don’t have full details on, but I can’t imagine police not investigating everything that happened there. Even if they were in dire times or even deemed as situational psychosis, you are put in a mental institution if you plead guilty but insane. But almost all of the deaths were cut and dry murder. Did/have they talked about not saying anything when they got back? I highly doubt every one of them lied and covered up all the murders, and that the police did no investigating. How could they get away with all of this..?