Beyond A Reasonable Doubt
Beyond a reasonable doubt is a term that represents the highest level of proof and certainty in criminal procedure required to return a verdict of "guilty." Before the jury retires to deliberate on the verdict, courts generally deliver instructions that the jurors should not find the defendant guilty unless they are convinced beyond a reasonable doubt of the defendant's guilt. The Supreme Court requires these instructions to be given to the jury in cases where extraneous considerations and outside influence may influence the jury's verdict, rather than the force of the prosecution's evidence and arguments.
"Beyond a reasonable doubt" is instead sometimes called "to a moral certainty," and these names in themselves suggest the difficultly in pinpointing the precise meaning of the phrase. Beyond a reasonable doubt is not the same as absolute certainty, but it's meant to be pretty close. It's meant to signifiy a far stricter standard than the "preponderance of evidence" required to render judgment in a civil law case. In criminal trial, the jury must not only be convinced of their verdict after an impartial and rational consideration of the evidence presented in the case (or lack of evidence), but must be as certain of the verdict they deliver as they would in the execution of the most crucial of their own affairs. The jury must decide that the defendant is guilty "beyond a reasonable doubt" of every single element of the crime before they may deliver a verdict of "guilty."
The requirement that a jury be convinced of the defendant's guilt beyond a reasonable doubt supports the principle of the presumption of innocence that governs the criminal law of the United States. The people of this country have decided that there should be as little frivolity and bias in assignment of guilt, and requiring every jury member to deliver judgment on the basis of his or her best reasoning and deepest moral certainty is believed to be in harmony with the principles of a free society.