As I stated above, if a relative or relatives did plant blood in the silencer, they may not have cared about the blood group or other forensics. The objective may have been simply to plant blood in the silencer that was recognisably human. The import of doing so may not have been fully appreciated and the evidence may have been then interpreted against Jeremy. That two of the people involved supposedly have the same blood group is not a coincidence - it's statistically quite likely.
I agree entirely, and has anyone ever seen the blood group analysis source materials? How does anyone know for sure that Sheila Caffell's blood group is what the police say it is? My understanding is that the original laboratory documentation stating the blood group analysis is among the papers that Essex Police refuse to disclose. I believe that Robert Boutflour dripped his blood inside the silencer so as to keep the investigation going at a time when the police had absolutely no evidence upon which to prosecute Jeremy and the case was about to be 'shut down'. I also believe that he was assured that Essex Police could 'fix' the paperwork to make it appear that the blood came from Sheila Caffell.
At trial there was a deliberate deception. As a way of obscuring the information that had come to light about the origin of the blood, i.e. it was identical for Sheila Caffell and Robert Boutflour, it appears that the police or the prosecution deliberately produced a list which the prosecution referred to at the trial, but the list omitted any of the relative’s names, including, crucially, Robert Boutflour.
Therefore when giving scientific evidence, forensic scientist John Hayward made reference to a list and as a result Hayward was able to tell the court that the only person on the list whose blood was found inside the silencer was Sheila Caffell. Incidentally, this confirms beyond any doubt that the prosecution QC, Anthony Arlidge, was also aware of the deception being practiced by Hayward, for it was Arlidge who asked him to consult the ‘list’. The questioning of Hayward was purposely misleading:
The following exchange took place in relation to blood found inside the silencer.
Q) Mr Arlidge: Did you test further any of that blood?
A) Hayward: I did, Sir, and found that this blood was also of human origin and I obtained grouping reactions for group A PGM1+EAP BA AK1 Hp 2-1
Q) Mr Arlidge: Looking at those items you have given… it appears that those correspond with the grouping that you found for Sheila Caffell?
A) Hayward: That is correct Sir
Q) Mr Arlidge: But not with anybody else on our list?
A) Hayward: That is correct Sir
The list that Arlidge referred to contained the names of the five victims plus Jeremy Bamber. Therefore Mr Hayward answered truthfully that the only person on that list with the blood group A PGM1+EAP BA AK1 Hp 2-1 was Sheila Caffell.
However, Mr Hayward was aware that blood samples had been taken from some of Jeremy Bamber’s relatives and the blood was also an identical match for Robert Boutflour. Mr Hayward did not disclose this to the Court. It is prima facie evidence that Hayward and Arlidge were engaged in a conspiracy to pervert the course of justice as both men knew that the Jury was not being told the full story.