concurring specially: I concur in the result reached by the court. I write separately only on the issue of the extent to which the State may employ the testimony of its expert resulting from a court-ordered psychiatric or psychological evaluation of the defendant. The court seems to decide this case on the basis of the State’s representations that it will only use the evidence in rebuttal to the defendant’s expert on matters the defendant places in issue. It is my view, however, that the State has correctly anticipated the constitutional limitations on the use of such evidence under part I, article 15 of the New Hampshire Constitution, which is also the standard recognized in United States v. Byers, 740 F.2d 1104, 1113 (D.C. Cir. 1984), and I would so restrict the State on the force of that provision.