proof beyond a reasonable doubt requires at least a 60 percent probability of guiltPerhaps proof to an utterly conclusive and absolutely certain certainty with no suspicion of a hint of a shadow of a doubt would require that the probability of guilt be shown to be 100%?
proof beyond a shadow of a doubt puts the bar at 70 percent
proof beyond beyond all doubt sets the bar at 80 percent, and
proof to an absolute certainty raises the bar to 90 percent.
But given the prosecutor's view of matters it hardly matters which formulation of the prosecution's burden of proof would require that the trier believe that the chances of a defendant's guilt are 100% -- because on the prosecutor's view of the reasonable doubt standard a trier of of fact can find a defendant guilty of a crime such as murder even though the trier thinks there is a 40% chance that the defendant is innocent. (The prosecutor quite evidently -- dare I say certainly? -- thinks that it is important not to set the bar too high.)
The prosecutor's view of the meaning of reasonable doubt is somewhat at variance with the view of the medieval philosopher Maimonides, who declared "it is better and more desirable to free a thousand sinners, than ever to kill one innocent." United States v. Fatico, 458 F. Supp. 388, 410 (E.D.N.Y., 1978) (quoting N.L. Rabinowitz, Probability and Statistical Inference in Ancient and Medieval Jewish Literature 111 (1973). Compare Justice Harlan's concurring opinion in In re Winship, 397 U.S. 358, 368 (1970), where he said that the reasonable doubt standard is "bottomed on a fundamental value determination of our society that it is far worse to convict an innocent man than to let a guilty man go free." Id. at 380.