Does that mean Ron can be prosecuted or does he get a pass too
I suppose anybody who is still alive can be prosecuted. Even if somebody is in their 70s/80s, if they perverted the course of justice, then they are fair game for the authorities; but, at that age it sort of becomes academic, doesn't it.
To be honest, I can't really picture Ron deliberately planting evidence or engaging in funny business to that extent, but - assuming it happened - he might have known about it and kept his mouth shut, if you see what I mean. Who knows?
I can imagine Ann doing this, on the basis of a 'vital interest', as I call it.
I can just about imagine Stan doing it, if he thought Jeremy was guilty and wanted to nail the case.
But first thing's first: How did that paint get on the silencer? That must be established before we start pointing the finger at people.
The prosecution say it happened in a struggle, but I don't see how it could have. I think that GER is wrong and it's also not good enough, as one or two people have said above, to suggest it must have happened before the incident. If Sheila deliberately put those scratches there at some point beforehand, June must have noticed and Jeremy must have known about it and would speak up. That's before we get into how the brim of the silencer could make those scratches and collect the paint traces in the knurled ribbon. Is that possible? And what would Sheila be doing with the silencer in the first place? And does that then lend credence to Jeremy's original defence at the 1986 trial?
As a first step, I would say somebody needs to take a look at the same model of Parker Hale silencer and then think about how the scenario claimed by the Crown could be tested in a reliable and scientific way. You'd probably need to start by scratching a painted surface with it similar to the aga surround of that time, to see how the scratching occurs and where the paint goes. If that's consistent with the prosecution theory, then maybe stage a reconstruction to see if the silencer could have impacted the surround and made those scratches while flat to the surface.
Are there experts who undertake such tests?