If Bud Kelly was on the scene during the initial investigation or if anything belonging to him is found on the evidence, then his lawyer will try to pass it all off as Bud Kelly contamination. They could just claim that standards were more relaxed back in 1966 in handling evidence. What you would need is to show some lab somewhere stored the blood sample and skin cells away from possible contamination.

It wouldn’t surprise me in the least if they have already found evidence pointing at someone official in these cases and wrote it off as contamination.