Burks (D) was convicted for robbing a federally insured bank by use of a dangerous weapon. D used insanity as his defense, providing expert witnesses to testify that his mental illness at the time of the robbery made him incapable of conforming his conduct to the requirements of the law. The government (P) rebutted this argument with two experts claiming that D was not mentally ill. P also produced lay witnesses to attest to D's sanity. D appealed, claiming that he was not criminally responsible. The Court of Appeals agreed with D that the evidence was insufficient to support the verdict. It remanded the case to the trial court, holding that P's evidence, even when viewed in the light most favorable to P, did not effectively rebut D's proof with respect to insanity and criminal responsibility. It gave the District Court the power to decide whether a directed verdict of acquittal should be entered or a new trial ordered. D claimed that the Court of Appeals' holding was nothing more or less than a decision that the District Court had erred by not granting his motion for a judgment of acquittal. D claimed that it made no difference that the determination of evidentiary insufficiency was made by a reviewing court since the double jeopardy considerations are the same, regardless of which court decides that a judgment of acquittal is in order. The United States Supreme Court granted certiorari.