William J. Brennan, Jr., Speiser v. Randall — Opinion of the Court
“ There is always in litigation a margin of error, representing error in factfinding, which both parties must take into account. Where one party has at stake an interest of transcending value-as a criminal defendant his liberty-this margin of error is reduced as to him by the process of placing on the other party the burden of producing a sufficiency of proof in the first instance, and of persuading the factfinder at the conclusion of the trial of his guilt beyond a reasonable doubt. ”
