Had the relatives ever been in trouble with the law before ?
No idea but BW made an official complaint to EP about PE and what she considered was financial irregularity.
Did the relatives know there was no other evidence which showed Sheila was the killer.
Well Chief Sup Harris and DCI Jones seemed pretty certain SC was responsible in the early stages. DCI Kennelly (spelling) undertook a further review and formed the same opinion.
Did the relatives know about back splatter.
They were obviously knowledgable about firearms in the context of farming/hunting but unlikely to be forensically aware. I have asked farmer friends and they inform me the only time blood from an animal comes into contact with a firearm is where something has been wounded and is then put out its misery be breaking its neck and blood from hands then touches the firearm
Did the relatives know there was no back splatter already on the rifle nozzle.
Only if they made enquiries or were told.
Did the relatives know that one of Sheila's shots was a contact shot.
Only if they made enquiries or were told.
Did the relatives know the rifle with the silencer on was too long for Sheila to shoot herself.
You asked this in the other thread.
Did the relatives know where to get Sheila's blood.
Not in sufficient quantity to produce the blood group results from inside the silencer
If unable to get Sheila's blood, did the relatives know what blood type she was.
Unlikely they even knew SC's ABO group. I think we can safely assume they would have zero idea about SC's enzyme and protein groups.
Did the relatives know who in the family had Sheila's blood type.
Extremley unlikely
Did the relatives know how to expertly put Sheila's blood/blood type into the silencer. Creating the back splatter effect.
The blood found in the silencer wasn't compatible with drawback in terms of the stain pattern. GSW's produce a mist like spray not flakes. Unlikely the relatives were this forensically aware.
Did the relatives know when WHF was empty so they could go back and scratch the aga.
Yes. They had the free run of WHF from about 5pm 9th Aug when police handed keys over. I have always thought it strange how PE and Cris Nevill stayed in CN's campervan on night of 10th Aug ostensibly to maintain security and protect the valuables. This makes little sense to me. A newly fitted alarm had been fitted. And during the day on 10th Aug all valuables were removed including firearms.
Did the relatives know how to scratch the aga to suggest a kitchen fight.
I haven't seen any expert evidence analysing the scratches in terms of whether or not they supported a fight. I don't think anyone including staff at FSS were that forensically aware then.
Did the relatives know that the crime scene photos did not already include pictures of the aga without the scratch's.
Unlikely unless they asked or were told by others
Did the relatives know where to get a strand of Nevill's hair.
Yes they would be all over the place: car, back of chairs, hats, coats, jackets, combs.
Did the relatives know the risks in attempting this frame and the punishment if found.
We don't know the relatives attempted a frame. If they did they might have been aided and abetted by the police and thought it was ok and they would get away with it.
Did the relatives know that each other could be completely trusted in a big crime committe
We don't they were involved in anything criminal. If they were it may have amounted to one or two.
Phew

What do all these questions and answers mean Adam?
Have you considered that the blood on the outside, paint and hair might have been fabricated to create the idea the silencer was used. Ie it may have been initially geared towards NB was beaten with it hence the paint and hair (blood externally unknown). When this was deemed insufficient others fabricated the blood internally and blood test results as we know them.