Freeman, 514 F.2d 1184, 1192 (10th Cir.197 . The court "can exclude irrelevant facts and stop ar- gument if it occurs." Zielie, 734 F.2d at 1455. The Insanity Defense Reform Act provides: It is an affirmative defense to a prosecution under any Federal statute that, at the time of the commission of the acts constituting the