During the PH, DVD or BVD, I forget which, was asked if Bill Libby ever spent the night at the VD home. Whomever it was said "no". Why did he ask that question, he did not ask if any of the other pizza partiers had "spent the night"?
During his opening statement, Feldman "promised" that we would hear "more" about Bill Libby, unfortunately, for some reason, he did not bring up Bill Libby.
It's not Feldman's job to find the killer, but I think he has a pretty good idea of who the "real" perp(s) is/are.