Beyond reasonable doubt is the standard of evidence required to validate a criminal conviction in most adversarial legal systems.
Generally the prosecution bears the burden of proof and is required to prove their version of events to this standard. This means that the proposition being presented by the prosecution must be proven to the extent that there could be no "reasonable doubt" in the mind of a "reasonable person" that the defendant is guilty. There can still be a doubt, but only to the extent that it would not affect a reasonable person's belief regarding whether or not the defendant is guilty. "The shadow of a doubt" is sometimes used interchangeably with reasonable doubt, but this extends beyond the latter, to the extent that it may be considered an impossible standard. Reasonable doubt is therefore used.
If doubt does affect a "reasonable person's" belief that the defendant is guilty, the jury is not satisfied beyond "reasonable doubt". The precise meaning of words such as "reasonable" and "doubt" are usually defined within jurisprudence of the applicable country.
Famous quotes containing the words reasonable and/or doubt:
“A man that is ashamed of passions that are natural and reasonable is generally proud of those that are shameful and silly.”
—Mary Wortley, Lady Montagu (1689–1762)
“When any man expresses doubt to me as to the use that I or any other woman might make of the ballot if we had it, my answer is, What is that to you? If you have for years defrauded me of my rightful inheritance, and then, as a stroke of policy, of from late conviction, concluded to restore to me my own domain, must I ask you whether I may make of it a garden of flowers, or a field of wheat, or a pasture for kine?”
—Matilda Joslyn Gage (1826–1898)