Well we shall never know now will we? But it does surprise me that there was not bloodspatter on her nighty as blood spatter would be a common thing I would have thought if someone was shot with a rifle? I'm no an expert of course, but I would have thought that there would also be negligable bloodspatter on the shooter as well as it was a long gun and not a handgun.
But having said that I still think it might have yielded some interesting things? It is always better to see the actual item rather than reading a report that someone else has compiled.
A contact wound features the spatter going inside the muzzle instead of away from the victim onto those around the victim. A non-contact would will result in spatter going towards the shooter and others who are nearby.
So the spatter will only hit others in non-contact wound situations and only if the shooter or someone else is standing close to the victim. Since the blood shoots away from the victim it will not usually get on the victim. A drop or 2 maybe but not any discernable pattern really.
That is why spatter is so valuable. Spatter means you were near the victim so you either are a witness or perpetrator if you have spatter present on you.
The closeness of some of the shots to the parents says the shooter would have had spatter and the lack of any to Sheila's gown is a good indication she didn't fire the shots. High velocity spatter is small so distant photos are unlikely to capture it we really need the expert testimony for such. The prosecution and defense experts of course found nothing. Medium velocity spatter stains are larger those we would be likely to see in photos. So if she had beaten Neville we should see spatter on her gown from such. The blood is only the giant stain on her shoulder and then the hand stain though.
The only blood to DNA test was from the hand stain area and the shoulder. They already tested such and it was determien dot be her blood. The chance of it coming up as someone else's DNA is astronomical there simply is no explanation of how someone else's blood could get there because it was not spatter but blood that flowed down her shoulder and arm to her wrist that she transferred.
The chance that the real killer cut his hand and got his blood on her wrist and his blood was then transferred to the gown is so remote it is not even worth considering and obviously would not help the defense anyway unless the killer were some thrid party no one even thought about. If it is Jeremy it would confirm his guilt instead of helping the defense.
If there were a realistic possibility of someone else from outside the house having killed everyone other than Jeremy then DNA testing of all the evidence could be far more useful to the defense.