The fundamental principle of fairness in a criminal trial is that the Defendant can be found guilty only upon evidence that leads the jury to find him guilty beyond a reasonable doubt. It is critical that the moral force of the criminal law not be diluted by a standard of proof that leaves people in doubt whether innocent men are being condemned. Because this is a federal standard, no state can drop below. A constitutionally deficient reasonable doubt instruction is reversible error because there is no jury verdict within the meaning of the Sixth Amendment without a proper reasonable doubt instruction. Sullivan v. Louisiana 113 S.Ct.
Reasonable doubt is determined by the evidence.
It is not a vague or capricious notion, but a doubt based upon reason. It is a doubt that would cause you to hesitate in the most important affairs. If one is not morally certain and convinced of guilt of the accused, that person has a doubt based on reason. Such a doubt arises from the lack of evidence, unsatisfactory evidence, a conflict in the evidence, or a want of evidence. The Defense must be able to review the breath of the government investigation and all the information generated during its course.