Sorry but I work in commercial / corporate field so do not have intimate knowledge of judges directions to juries regarding reasonable doubt.
All I can say is of the many many people I have come across in the legal field over my years in practice, nobody has ever openly stated that 99% is enough to convict and the vast majority air towards over 99.9%. No judge will ever direct a jury to consider percentages tho, which are of course arbitrary.
Basically to pass a guilty judgement you have to have no doubt at all that the accused is guilty (barring some unreasonable doubt!)
There are few passages in the English law reports better known than that in the speech of Viscount Sankey, the Lord Chancellor, in the House of Lords appeal case of Woolmington v. The Director of Public Prosecutions, when he said:
“Throughout the web of the English criminal law one golden thread is always to be seen, that it is the duty of the prosecution to prove the prisoner’s guilt … . If at the end of and on the whole of the case, there is any reasonable doubt, created by the evidence given either by the prosecution or the prisoner ... the prosecution has not made out the case and the prisoner is entitled to anacquittal. No matter what the charge or where the trial, the principle that the prosecution must prove the guilt of the prisoner is part of the common law of England and no attempt to whittle it down can be entertained.”
Thanks Petey.
The part in red intrigues me, I'm not sure if you mean what you have written, or more likely I'm misinterpreting what you have written.
The passing of Judgement is carried out by a Judge, based on the verdict of a Jury (if present), so who needs to have no doubt (barring unreasonable doubt), the Judge and the Jury or just the Judge?
I guess what I really mean, is that despite the legal opinion of what is or is not reasonable doubt amongst legal professionals, in percentage terms or otherwise, a Jury is by design made up of lay people who would be unlikely to know the definition of "beyond reasonable doubt" unless advised, and even after being advised would likely be understood and interpreted individually, the understanding amongst jurors would then quite likely be inconsistent.
I know I'm rambling, and probably not making a great deal of sense, but I couldn't tell you the difference between being 90% sure of something, or 95%, I most certainly wouldn't be able to distinguish between 99.5% and 99.9%. Maybe it's just me and I'm not very good at applying percentages.
In fact I think I've completely forgotten what my point was.