I've recently come across the following article by Jim Shelley. I've copied and pasted the sections that relate to draw-back and back spatter below and included the full link:
http://en.wikipedia.org/wiki/Jim_Shelley_(TV_critic)
http://jimshelley.com/crime/jeremy-bamber/Malcolm Fletcher - Senior Scientific Officer - Prosecution"Apart from the traces of blood, there was nothing to indicate that the silencer had been used. Malcolm Fletcher, a firearms expert testifying for the prosecution, said: “I have been unable to establish whether any of these bullets or bullet fragments have been fired through a sound moderator (silencer).”
"He admitted under cross-examination that a .22 calibre weapon was “the least likely” weapon to produce “backspatter”, and that a silencer made it less likely still".
"Apart from the traces of blood, there was nothing to indicate that the silencer had been used. Malcolm Fletcher, a firearms expert testifying for the prosecution, said: “I have been unable to establish whether any of these bullets or bullet fragments have been fired through a sound moderator (silencer).”
John Hayward - ?Biologist - ?Prosecution"At the trial, the Judge emphasised to the jury how, from experience, Hayward could judge the possibility of a mixture by appearance. Hayward had said the opposite and, in fact, under cross-examination, admitted he had never in all his experience seen “backsplatter” before".
Major Freddie Mead - ?Forensic Ballistics - Defence"Freddie Mead, an expert in forensic ballistics and a specialist in the investigation of accidents involving firearms for the army, told me: “The speculation in the Learned Judge’s summing up is totally wrong.” Mead’s conclusion is that “there aren’t any grounds to believe a silencer was involved, apart from that the silencer was found.”
http://www.jeremybambertestimony.co.uk/helenaI've no idea who Helena is but she writes well and I think hits the nail right on the head when she says:
"However, it was the introduction of a sound moderator and the speed at which it became the integral factor of the case which baffled me most of all. Since it was believed from the outset that it was a murder/suicide investigation, it would seem to me that the rational process of thought would be to repudiate the sound moderator as opposed to an attempt to choreograph a correlation between the implement and the crime".