ISTM that in those days, analysis of forensic evidence of bodily samples was according to blood type.
Of blood, it was.
The blood found inside the moderator (silencer) was that of Caffell
Not correct. The blood found has never been shown to be Sheila's. Before you mention the DNA analysis (the usual thing that guilters trot out), that was an LCN analysis without attribution to trace and was, quite rightly, dismissed as meaningless by the 2002 appellate bench.
and had been placed back on the rifle and returned to the cupboard.
Wait....I understand the point about returning the moderator to the cupboard, and clearly, even if the moderator wasn't used in the killings (which is my view about it), it's the Crown's position that it was found there, and bizarrely enough, that is (or was) the Defence position too.
The bit I don't understand is "placed back on the rifle". Who says that happened? Genuine question, I'm intrigued.
The prosecution case was that her arms were too short to have been able to shoot herself with the moderator on
This is one of those Aunt Sally prosecution points that I have always dismissed in my own mind because we don't know, and the point wasn't tested scientifically in the way it would be today. Ironically, the Defence showed post-trial, I think prior to the 2002 appeal, that she could have shot herself with the moderator on, but again, their test was no more reliable than the prosecution's back in 1985/86.
and obviously could not have returned the gun to the cupboard once she had done so.
Agreed.
Bamber's defence was that the blood inside the moderator might have been a mix of Neville and June, the parents and they were trying to requisition the original report and possibly samples. The only way this would work is if Sheila and either of Neville and June were blood type A and the other parent blood type B, with Sheila being AB.
The bloods were inconclusive, as was DNA. I am focusing here on the blood inside the baffles only. I ignore the blood on the outside of the moderator because that is too susceptible to contamination during custody and examination.
My recollection of the evidence is that, at trial, Hayward had found that the blood inside the baffles was from the same blood group as Sheila's, but he could not exclude the possibility that Nevill's and June's blood was there too or instead of it. I will accept that the bloods are probably human, which in turn must present the Defence with a serious problem because, regardless of how the bloods are grouped, an onus shifts to Bamber to, either, provide a plausible explanation within the framework of the narrative of events, or, explain why we should dismiss the finding.
Overall, though, I would dismiss the moderator. I regard it as inconclusive evidence because:
- the context of the evidence undermines it. The chain of custody is flawed and DI Cook's reputation was undermined in court;
- there is no evidence - none at all - that the moderator was used in the killings. Guilters like to mention the lack of traces of back spatter inside the rifle barrel, but in itself that does not establish the point because back spatter is not inevitable;
- the forensics are inconclusive using current available technologies. We don't know for sure whose blood it is, and it is even possible that it's not human blood (a remote possibility, but the defence expert, Webster, put it at 5%, which is too high if we're talking about keeping somebody in prison). Despite guilters' disingenuous claims, we also don't know whose DNA is there;
- the Crown offered no evidence concerning the quantity of blood inside the internalised baffles. In retrospect, this was a serious error in my view, because a significant quantity of human blood would have amounted to evidence in and of itself with an onus on Bamber to rebut or refute; and,
- the Crown did not provide supporting evidence for the expert view that the patterning of the blood in the baffles was consistent with a gun shot. We are asked to rely on the opinion of experts in this regard, which given the context of the evidence, I don't consider is good enough.
Although it is clear to me Bamber is guilty as charged, it strikes me that it would now be useful to do a full DNA analysis of this blood to settle the matter once and for all.
Agreed.