concurring:
I join in the opinion of the panel, but note that when sitting as a member of the Supreme Court I have agreed that appellants, upon whom the burden of proving insanity was placed, were convicted unconstitutionally under both the Pennsylvania and federal Constitutions and are therefore entitled to new trials. Commonwealth v. Ernst, 476 Pa. 102, 109, 381 A.2d 1245, 1248 (1977). (Roberts, J., dissenting).