what do I do

lets say, hypothetically, that one might have knowledge that a family member- back in the day- might have been involved with a complicated situation involving some legal cases. Specifically, a judge, who handled some major cases in the 70's, until current, who may not have been as ethical as a judge or clerk should have been. lets say, hypothetically, that another family member left a box of, we will call it, creative accounting, and lets just say- the person who has such a box just wants to do the right thing . Whom would such a person notify? hypothetically, of course