I was wondering the same thing. All I can think is everyone involved is probably dead.
There's two people who are widely suspected of being involved that are still around: Jack Tocco, who was the acting boss of Detroit when the hit went down, and Tommy Andretta, who helped with clean-up at the scene of the hit.
Would be nice to see Chuckie O'Brien go down if he really had anything to do with it, as the family suspects he does.
From what I gather he wasn't really involved with the murder conspiracy.
