(concurring).
I concur since this case represents another salutary application of McDonald v. United States, 114 U.S.App.D.C. 120, 312 F.2d 847 (1962), in that the weight of expert testimony is exclusively for the jury, not for the court, once qualifications are established. In this case the evidence of mental disease adduced by the appellant probably did not rise to the level called for by the new standards of *276McDonald, but we need not reach the point since, in an abundance of caution, the District Court gave an instruction on criminal responsibility which is not challenged.