Can someone provide the source that RB had the same blood type as Sheila. There is nothing in the COA.
I believe all family members involved in the case had their blood taken by the police. Off-hand I can't remember specifically who, but it probably included Robert Boutflour. This happened at some point in 1986 in the run-up to the trial. There is a document concerning it. I will dig it out of my records at some point but it is on the Forum.
Mike speculated that these tests could have been carried out due to suspicions on the part of the police that family members may have planted the silencer evidence.
As for whether family members could have known Sheila's blood group, we know that Sheila was in direct correspondence with Peter and Ann Eaton and she knew David Boutflour quite well. I do agree with you that it would be rather strange for them to know her blood group, but it is not an impossibility and remember also that Sheila had contact with doctors and either Sheila or June could have let slip the information in mundane conversations with family members. At the end of the day, they all knew each other so the possibility that they knew Sheila's blood group cannot be ruled out, even though I agree it's strange.
Also, remember that the family were close to the police investigation and so it is not out-of-the-question that very early on somebody told them Sheila's blood group or they learned it or even overheard it.
Furthermore, it is possible that somebody planted the blood in the silencer without giving any thought to blood analysis, simply in the belief that any sort of human blood found in the silencer would be incriminating, while at the same time working on the assumption that the police would be unable to match the blood to a particular person. Remember, this was before the days when DNA was used routinely in criminal investigation - that technology was still in its infancy in 1985/86 and not widespread practice, so people like the Boutflours and Eatons, and probably most police officers and forensic scientists, would have no knowledge of it.
There was another thread I started on here where I considered the blood evidence in the silencer and my conclusion was that the blood pattern in the silencer is consistent with the blood having been deliberately put there by somebody. I also concluded, in another thread, that the silencer could not have caused the scratches on the aga. None of this is to say that the silencer evidence was fabricated. I just don't know that.
