It's been suggested that Sheila put the silencer on herself. After Bamber left the rifle minus the silencer in the kitchen. Her blood dripping from her hands deep into the baffles.
There are several reasons why Sheila would not put the silencer on:
Nevill was already awake.
Sheila was on Haloperidol and had no co ordination or energy.
Although sedated and drowsy she was apparently in a rage. So not likely to be calm enough to attempt to try something intricate.
Sheila did not know how to put the silencer on.
The silencer was not near the rifle.
Sheila had no time. As Nevill was awake.
Sheila would not have taken the silencer off and put it in a box at the back of a cupboard after the massacre.
Sheila did not know how to take the silencer off.
The expert evidence is the blood inside the silencer baffles was from rifle shot back splatter from contact shots.
Nevill would not have heard upstairs shots if downstairs phoning Bamber if the silencer was on.
There was already noise inside WHF from a 'crazy' Sheila and an awake Nevill. So too late to attempt a quiet massacre.
The rifle shots would be just as effective in a massacre attempt without a silencer on.
Putting the silencer on would give Nevill more chance to tackle Sheila.
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I agree with a supporters view this week that neither the police or Stan Jones fabricated the silencer.
However I believe Sheila's blood, the aga paint and hair was due to the silencer already being on the rifle prior to Bamber picking it up. Or Bamber put the silencer on while everyone slept. Which he knew how to do.
Bamber then put the silencer away, virtually hidden. The relatives then found the silencer shortly after the massacre.