Criminal Law
Beyond a Reasonable Doubt
Definition
Beyond a reasonable doubt is the highest standard of proof in the American legal system, required for a criminal conviction. The prosecution must prove every element of the offense to such a degree that there is no reasonable doubt in the mind of a rational juror. This standard is constitutionally required under the Due Process Clause, as established in In re Winship. Reasonable doubt is not any possible doubt or speculative doubt — it is doubt based on reason and common sense after careful consideration of the evidence.
Example
A jury convicts only if, after considering all the evidence, each member is firmly convinced of the defendant's guilt. If any reasonable doubt lingers, the jury must acquit.