If we assume the relatives decided to intentionally contaminate the silencer, then this is my response. To be clear, I don't believe there is evidence currently to support the view that they did, but I will outline my thinking on Adam's points anyway.
The relatives would need to do the following things. I have added a few things -
Have the idea.
The first thing is that they need a motive. I've dealt with this already further up the thread. I've covered the possibility of a 'vital interest' motive and explained what further research I believe is necessary to establish it. I've also touched on the possibility of a psychological motive on the part of David Boutflour.
In addition, we need to consider the type of people we're dealing with. Again, I've covered this further up the thread. These are 'gun types', but they will be lacking in sophisticated ballistical knowledge. This means they will have enough knowledge to appreciate what needs to be done and they will approach the matter logically, but they may slip up in that they lack the fuller knowledge of the illogical ins and outs that a forensic ballistic expert would be more aware of.
Agree with each other to attempt this. Knowing the consequences if caught.
One person found the silencer, so in principle, it would require no more than one person. Let's err on the side of caution and say there were two people involved: David Boutflour and Robert Boutflour. Let's say they decide on the plan after David finds the silencer (on the search of the house with Ann and Peter). Let's say they decide not to reveal their plan to Ann Eaton because she's a woman and they think she will not hold up under scrutiny. They also decide not to tell Peter Eaton because they think that he may then blow the gaff by telling Ann. They also agree that on no account should the scheme be disclosed to Karen Boutflour or Pam Boutflour.
[One problem with my idea here is that, if I understand correctly, they take the silencer back to Ann's house, so it needs more thought - but take this as my 'starter for 10'].
Agree with each other to attempt this knowing how much work will be needed & how much they need to find out.
This is a good point, actually. The problem is this: the two of them will know about guns, but they're not ballistic experts and they may need to find out more about the finer points. How do they do this without raising suspicions? There again, maybe this explains the close interest of Robert Boutflour and some of the other relatives in the police investigation and maybe David and Robert were encouraging Ann in this interest or allowing her to pursue her interest, for this reason?
David and Robert will also make the fair assumption that the police are not keeping tabs on them or tapping their phones, etc., so there is no risk to them in communicating with each other as there would be if they were potential criminal suspects or key witnesses.
Know if successful, it still may not convict Bamber if there is strong evidence incriminating Sheila.
Again, a good point, but this is a calculation they would have to make. The same observation could be made about any piece of evidence.
I suppose what Adam is really getting at here is that there would be a high risk that Jeremy would intuit that the relatives are trying to trap him and set him up, and if we assume a vital interest motive, then a reasoned calculation would have to be made: should the relatives go ahead and trap Jeremy criminally or should they try to reason with him from a business point-of-view and do a deal?
If they were being really crafty, the relatives may have been trying to synthesise those two lines of thought - i.e. set Jeremy up as a means to gain a negotiating advantage on him. 'Do a deal with us over the land and we'll tell the police we agree it was Sheila'.
I'm not saying I think that happened, but I just float the idea.
Know Sheila had received contact shots.
Again, good point - but they will have known this, or had the ability to find out.
Know whether the other deceased people received contact shots.
Good point again - but bear in mind that the order of the assault on the victims was not known, and furthermore, the relatives may not really have cared about this, or they may not have even thought of it. Remember that we are assuming they are 'gun people', but naive in forensic ballistics.
Also, blowback is not the only type of backspatter. Backspatter can result from non-contact shots and matter from backspatter can get into the end of a gun even if the shooter is some distance from the target.
Know where each person's contact shots were. Some areas are more likely to provide back splatter.
Again, perfectly fair point, but my response is the same as above. They simply may not have cared or given this much thought. They may have had the simple notion in their heads that you put blood in the silencer and that's enough. Why not?
Know there was no blood on the rifle barrel.
I've covered this point already in my original post that started the thread. The fact that Fletcher's testing showed no blood in the barrel could be seen as neutral. You could just as easily argue that a lack of blood in the barrel raises the question of how there could have been backspatter in the silencer. It does, however, depend on 'blood behaviour', and specifically whether backspatter blood can drip.
Know Sheila could not shoot herself with the silencer attached.
But they suspected Sheila was not responsible for other reasons, therefore this point of yours - while valid - would not have occurred to them and a conspiracy would not have hinged on it.
Know a silencer was not found next to Sheila.
Their own police statements confirm they knew this at the time. As gun people they knew that the rifle would normally have a silencer and telescopic sight attached.
Know about back splatter.
They wouldn't necessarily know about this in the scientific sense, but they would probably be aware of it as an empirical phenomenon. They would just need to have dismantled a silencer or cleaned a gun.
Know how to insert back splatter.
They wouldn't know, that's the whole point. It's why some people think intentional contamination is a possibility.
Know Sheila's blood group.
Why wouldn't they know Sheila's blood group? Is that so far-fetched? They would probably have learned this, either in the past, or during contact with the police during the investigation itself. Anyway, it needn't have been Sheila's blood. As you know, blood could not be linked to a specific individual at that time. Therefore, the same blood group was enough, and they may have been made aware of the family's blood groups during the inquiry, or at some point in the past for unrelated reasons. If they were aware of this, then it's likely that any human blood would do, due to the range of blood groups in the family. It need not have been Sheila's.
Know the blood group of the other deceased people.
Answered above.
Know whether any of themselves had the same blood group as Sheila.
Answered above. I will assume they knew their own blood groups, but I appreciate what you are getting at: especially back then, it wasn't a given. Interestingly, there's also an element of subjectivity in grouping blood, especially forensically, which I assume also applies medically.
Know there was no other evidence which incriminated Sheila.
Doesn't matter. They already believed this at the time. It's confirmed in their own evidence.
Know the crime scene photographs did not show the aga.
They are not criminalists, forensic photographers or crime scene experts. They would not necessarily have thought about that. Ironically, sometimes a lack of knowledge and forethought can be an advantage in life. People with lots of knowledge about a subject hesitate, while people with little or no knowledge but bags of confidence may jump in and get it done.
Know there was a kitchen fight where the rifle was used.
They did know.
Know whether the silencers had already been looked at by police.
They did know. That's the whole point.
Believe the police will bother to do something once they receive the silencer.
They had to. It's their duty. It's evidence.
Act quickly & submit the silencer straight away. Time was not on their side.
Well they didn't. They delayed. The police only collected the silencer after Robert Boutflour went up to Witham Police Station to ask what the hell was going on and it was realised there had been a misunderstanding. Stan Jones was then sent to collect. Or, at least, that's the relatives' story.
Accept they may be wrong & Sheila may be guilty. Meaning they are attempting to frame an innocent man.
Well Sheila was guilty of nothing, since she was dead. The dead are beyond the reach of the criminal courts and can't be convicted - or at least in England & Wales that is the case.
But taking up the thrust of your point, you too may be wrong, Adam. You may be blaming a living and breathing innocent man for a mass murder; but, I assume you could not and would not do that intentionally. You must genuinely believe Jeremy to be guilty.
Anybody could be wrong.
I think the family would only have done this if they sincerely believed he did it.
Accept a free Bamber may attempt revenge if he finds out the relatives turned on him.
This point has occurred to me as well, but I cover it above. At the end of the day, it boils down to the relatives making a considered calculation.
Not retract a word of their statements.
A good point and I've covered this already: I think the conspiracy would have been limited to just David and Robert and they would have concealed what they were doing from the others. The others may guess or wonder, but may not ask. That sort of thing does happen in families.
