I'm sure time won't tell.... 
Don't count on it - fact is that PC Whiddon did take the silencer from DCI 'Taff' Jones desk, and he did take it along to the force armoury, and he did screw it onto the barrel of the anshulz rifle, and he did all these things before that silencer (2) and the anshulz rifle, were both sent along to the lab' on 20th September 1985...
Now if he did that before silencer (2) and the anshulz rifle were sent to the lab' on 20th September 1985, then he obviously put the silencer at risk of being contaminated. This becomes important if we go along with the one silencer in existence approach, since it provides a legitimate opportunity for blood that was dried into and onto the thread on the end of the rifles barrel, to be forced by dynamic process back into the silencer when PC Whiddon screwed that silencer onto the barrel of the gun before 20th September 1985. The barrel of that rifle was pho0tograihed at the scene resting against the neck of Sheila in close proximity to running and leaking blood, and so it would not be too difficult to imagine how some of Sheila's blood could have got onto and into the thread of the rifles barrel at that point. If you then get two or more police officers screwing a silencer onto the thread of that rifle, then the consequences could be catastrophic in so far as contamination or the risk of contamination having occurred by these events having taken place...
