This is a heartbreaking story. I am so sorry. I think only those who have missed loved ones in these sorts of circumstances can understand the particulars of this kind of pain. I worte some days ago about a niece, and there was an uncle who was found dead in an abandoned road, shot in the back, some 13 years ago. No clues so far.
People usually find solace in the alleged rule that what you do in this life you pay for in this life. I know of many who died peacefully of old age without ever paying for anything.
Hopefully, you and your family will have some closure.