FACTS
We are presented with a very scanty transcript of the proceedings. Many of our background facts are drawn from the parties’ briefs or from statements made by the lawyers during motion hearings. These facts are included to set the stage for our opinion but cannot form a basis for resolution of the sufficiency-of-the-evidence question. “We can only decide a case upon what appears in the record before us.” Matter of Estate of Reed, Wyo., 566 P.2d 587, 590 (1977). Matters alluded to by attorneys at motion hearings or in briefs are not testimony and cannot be considered. Kirby Building Systems, Inc. v. Independence Partnership No. One, Wyo., 634 P.2d 342, 345 n. 2 (1981).
Mr. Zespy was charged with manufacturing and possessing psilocybin with intent to deliver in violation of § 35-7-1031(a)(ii), W.S.1977. He pled not guilty, not guilty by reason of mental illness or deficiency, and not competent to stand trial. He was examined by Dr. Burnett at the Wyoming State Hospital in Evanston, by Dr. Elkin, a private psychiatrist practicing in Casper, and by Dr. Miracle, a psychologist. They found that he was not mentally responsible for his actions under § 7-ll-305(b), W.S. 1977. The State determined, nevertheless, that it should proceed; and his jury trial began on January 14, 1985.
Although § 7-ll-305(b) had been amended to place the burden of proving insanity upon the defendant, the parties agreed that the older version of the statute applied. Under that version, once the defense produced some evidence of insanity, the burden shifted to the State to prove beyond a reasonable doubt that Mr. Zespy was sane at the time of the offense. Prior to its 1983 amendment, § 7-ll-305(b) provided:
“The prosecution shall prove beyond a reasonable doubt all the elements of the offense charged and the mental responsibility of the defendant. However, every defendant is presumed to be mentally responsible and the burden of first going forward and entering evidence on the issue of mental responsibility is upon the defendant.”1
There is no doubt that the defense produced enough evidence of insanity to shift the burden to the prosecution. Drs. Miracle, Elkin and Burnett all testified that Mr. Zespy was not mentally responsible for his actions when he committed the alleged crimes. In rebuttal the State called Dr. Lee Coleman, a psychiatrist from Berkeley, California, who had never personally examined Mr. Zespy. After inquiring into Dr. Coleman’s training, practical experience and writings, the prosecutor asked him to describe the kind of expert testimony he usually gave in criminal cases. Dr. Coleman responded:
“Because of my view about the limits on methods of the state of the art of psychiatry, I do not testify about the state of *566mind of the defendant at the time of the crime or whether a person will be dangerous or try to give a diagnosis.
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“So my testimony goes to whether or not the methods employed by the psychiatrists, who have already testified in the case, deserve any credibility. My opinion is that the state of psychiatry does not deserve to be given that credibility. We just don’t have the tools[;] therefore the answer to your question that whoever is bringing in psychiatry to try to prove their case, it will be the other side who might be interested in having me come in to testify about whether or not the methods are really reliable.
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“I am saying that the methods of psychiatry, the methods by which we decide upon diagnosis, the method by which we decide upon legal issues such as whether a person knew what they were doing was wrong or had capacity to conform. The methods psychiatry applies do, in my opinion, not come up to the standard of the expertise that the law thinks they do.”
Defense counsel objected to Dr. Coleman’s anticipated testimony on grounds that it would amount to an attack on the legislature’s determination that expert psychiatric witnesses are competent to render an opinion in insanity cases. The district judge asked Dr. Coleman if it was his position that there are no proper psychiatric methods which could be used to reach the conclusions set forth in the Wyoming statutes. Dr. Coleman said that it was proper for psychiatrists to testify under the law, but he did not believe that their opinions were entitled to any credibility. The judge then told the prosecutor that he did not understand how Dr. Coleman’s testimony would be admissible, and the prosecutor responded by explaining that the doctor would talk about the merits of the specific procedures followed by the other psychiatrists. The following discussion between the judge and prosecutor occurred:
“THE COURT: As I understand it, your witness is not going to say that the particular methods used by the experts for the Defense in this case were necessarily deficient, that something better could be done, but no matter what would have been done, it would not be sufficient. “MR. EVANS: I think that that is correct, except that his testimony is going to focus on what they did, if he has an opinion that there is a better way perhaps he could suggest it, but he is going to focus on what they did and express his concern and the concerns of a lot of American Psychiatric Association about methodology.
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“THE COURT: I think you are presenting the position to the wrong forum that belongs probably in the Legislature, the Legislature has given us a law we must work with, obviously the Legislature thought there were methods that could be used to reach conclusions, otherwise to say the law for the Legislature is not good, that is not for us to say here.”
Dr. Coleman then tried to explain ‘his prospective testimony to the judge:
“THE WITNESS: Well, what I intend to testify to once these qualifications were finished with, my expectation was to examine the methods and means used by experts who have testified for the Defense and give my opinion on the methods that were used.
“THE COURT: But you, as I understand it, have stated that there are no methods that could be used to present a satisfactory answer to the question in our statute.
“THE WITNESS: Well, they are satisfactory, they are legally permissible, what I would expect to testify is as to their credibility, how scientific, how psychiatrists arrive at diagnosis, are there inconsistencies in the record, are the statements of the doctors in their reports inconsistent with actual records of hospitalization, and many, many other such *567issues, which I found in my study of the records.
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“THE COURT: Well, I think, do I understand correctly, Doctor, what your position amounts to is you are saying there is not at this time any scientifically valid method, that can be applied to answer the questions posed by our statute? Is that right?
“THE WITNESS: Yes, that is true, methods don’t exist.
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“THE COURT: The problem with that approach, it seems to me, it is basically a statement that our law is no good, invalid, the Legislature is mistaken in this procedure. I do not think that is admissible.”
The district judge refused to admit Dr. Coleman’s testimony, because it would indicate that there are no valid methods in psychiatry which can be used to answer the questions posed by the insanity statute. According to the judge, this would contradict the legislature’s intent because the legislature was “obviously of the opinion there are some valid methods that can be used to answer the questions proposed.”
Without Dr. Coleman’s rebuttal testimony, the State was left with only lay witnesses to contradict the psychiatric testimony introduced by the defense. Relying on Reilly v. State, Wyo., 496 P.2d 899 (1972), the district judge held that lay testimony is insufficient, by itself, to prove sanity beyond a reasonable doubt when it is contradicted by the opinion of examining psychiatrists. Therefore, the trial court concluded that Mr. Zespy was entitled to a directed verdict of acquittal by reason of insanity.
REBUTTING EXPERT PSYCHIATRIC TESTIMONY
The constriction placed upon Reilly v. State, Wyo., 496 P.2d 899 (1972), was not correct. In Reilly, we held that a court may direct a verdict in favor of a criminal defendant if the prosecution does not provide any substantial credible evidence that he was sane. Id. at 902-903. We pointed out that, if the defendant’s evidence of insanity is strong, the State may not be able to provide substantial credible evidence simply by producing lay witnesses. But we never said that lay witnesses were always insufficient or that the prosecution must always produce a psychiatrist to contradict the defendant’s psychiatrists.
The proper rule is more clearly stated in Gerard v. State, Wyo., 511 P.2d 99, 104 (1973), a case which neither of the parties cited to the district judge:
“We noted in Reilly, supra, that neither the trial court nor this body should substitute its opinion for that of the jury, whose finding of fact should not be interfered with if there is any substantial evidence to support it. As the court said in People v. Krugman, 377 Mich. 559, 141 N.W.2d 33, 35 [(1966)], ‘The jury is the ultimate judge of defendant’s sanity at the time of the crime, and * * * since it had before it evidence of defendant’s behavior and state of mind upon the basis of which it could have found defendant sane at that time, it was not bound by the expert opinion testimony of the doctor. * * * ’ We again recognized this view in Jarrett v. State, Wyo., 500 P.2d 1027, 1031-1032 [(1972)], involving a murder charge, where we held that the trial court correctly denied a motion for acquittal notwithstanding the testimony of psychiatrists that defendant had suffered from a mental disease or disorder, our position being that the other evidence which had been adduced was sufficient to show that defendant knew and understood the nature and probable consequences of his act, knew that it was morally wrong or forbidden by law, and had sufficient will power to control his acts. As Mr. Chief Justice McIntyre said in Rice v. State, Wyo., 500 P.2d 675, 676 [(1972)], ‘A jury can always disregard the testimony of an expert if the jurors find it to be unreasonable.’ ”
There may be cases where neither lay testimony nor expert testimony by a non-examining psychiatrist is sufficient to re*568but the testimony of examining psychiatrists. If reasonable minds could not differ on the defendant’s insanity, then that issue should not be submitted to the jury, and a directed verdict of acquittal should be entered. But, a court should not grant an acquittal solely because the prosecution fails to produce an examining psychiatrist to rebut the testimony of the defendant’s psychiatrists. Under some circumstances, rebuttal by a lay witness or a non-examining psychiatrist may be sufficient to make the defendant’s sanity a question for the jury.
ADMISSIBILITY OF DR. COLEMAN’S REBUTTAL TESTIMONY
The State contends that the district court should have admitted Dr. Coleman’s rebuttal testimony under § 7-ll-305(d), W.S.1977, which states:
“In addition [to the designated examiners who examined the defendant for competency], the state and the defendant may summon other expert witnesses who did not examine the defendant. Such experts are not competent to testify as to the mental responsibility of the defendant; however, they may testify as to the validity of the procedures followed and the general scientific propositions stated by other witnesses. ” (Emphasis added.)
According to the State, this statute expressly permitted Dr. Coleman to attack the various tests employed by the defense psychiatrists. We agree.
When it was held that Dr. Coleman’s proffered testimony would undermine statutory procedures, the distinction between the competency of a witness and the competency of a witness’ opinion was improperly blurred. In § 7-ll-305(c), the legislature stated that examining psychiatrists are competent to testify about the sanity of the defendant.2 A rebuttal witness cannot argue that examining psychiatrists are incompetent witnesses who should not be permitted to testify. That matter is settled by the statute.
But, § 7-ll-305(c) does not say that the opinions expressed by psychiatric witnesses are automatically competent, i.e., credible. Through § 7-ll-305(d), the legislature has expressly permitted a non-examining psychiatrist to question the validity of the procedures and general scientific propositions presented by the examining psychiatrists. The legislature did not list the psychiatric procedures or propositions that it endorses. Nor did it limit the number of procedures or propositions that can be offered or attacked. If the examining psychiatrists offer every proposition or procedure for testing sanity that is known to man, a rebuttal psychiatrist can attack every one of them. And if the rebuttal psychiatrist can attack every test individually, there is no logical reason why he cannot attack them as a group by stating that there are no valid tests that have been developed by the psychiatric profession.
If the legislature thought that there are at least some valid psychiatric tests of sanity, it could have endorsed those tests in the statute. But the legislature did not do so. Apparently, the legislature could not decide which psychiatric tests, if any, are valid, so it left that decision to the juries on a case-by-case basis. The legislative intent is not violated when a rebuttal witness tells the jury that there are no psychiatric tests which can be used to ascertain sanity. Instead, such testimony helps the jury perform its delegated task, the evaluation of the psychiatric tests.
Under our interpretation of § 7-11-305(d), the jury is free to disregard the rebuttal testimony of a witness like Dr. Coleman and conclude that some or all of the tests performed by the examining psychiatrists are credible. On the other hand, the jury should also be free to conclude that there are no psychiatric tests that can help it ascertain the defendant’s sanity at the time of the offense. The jury would *569then have to decide the sanity issue based on evidence other than psychiatric test results. For example, it might have to apply its collective understanding of human behavior to the defendant’s criminal acts, his demeanor in the courtroom or his other out-of-court conduct.
The jury’s reliance on evidence other than psychiatric opinion is consistent with our opinion in Gerard v. State, supra, 511 P.2d at 104. There we said that a jury can disregard psychiatric testimony and rely on othér evidence which shows that the defendant knew his actions were morally wrong and that he had sufficient will power to control his acts.3 We quoted with approval the following statement:
“ ‘The jury is the ultimate judge of defendant’s sanity at the time of the crime, and * * * since it had before it evidence of defendant’s behavior and state of mind upon the basis of which it could have found defendant sane at that time, it was not bound by the expert opinion testimony of the doctor.’ ” Id., quoting People v. Krugman, 377 Mich. 559, 141 N.W.2d 33, 35 (1966).
Of course, the jury would have been free to ignore Dr. Coleman’s views and rely upon the opinions of the defendant’s psychiatrists. In either case, the jury would have ultimately applied the legislature’s definition of insanity. Dr. Coleman’s critique of all psychiatric testing would not have interfered with the jury’s ability to determine Mr. Zespy’s sanity under the legislature’s definition of that term.
In conclusion, the district court should have allowed Dr. Coleman to testify about the tests conducted by the examining experts. He should also have been permitted to testify that there are no psychiatric tests upon which a psychiatrist can base a valid opinion about a defendant’s sanity. This kind of testimony is permitted by § 7-11-305(d), W.S.1977. It would not have nullified the legislature’s decision that examining psychiatrists are competent witnesses, and it would not have prevented the jury from applying the legislature’s definition of insanity.
SUFFICIENCY OF THE EVIDENCE
The State argues, in a perfunctory manner, that there would have been sufficient evidence of sanity to prevent a directed verdict if the court had permitted Dr. Coleman to testify. This is not the kind of legal issue which merits attention in a bill of exceptions. Our analysis of the sufficiency of the evidence under the facts of this case will have no impact on either of these parties or future litigants. Moreover, the record does not contain any psychiatric or lay testimony other than the statements of Dr. Coleman. With this record, we would not be able to comment on the sufficiency of the evidence even if it merited our attention. See Matter of Estate of Manning, Wyo., 646 P.2d 175, 176 (1982).
. The statute, as amended, provides:
"The prosecution shall prove beyond a reasonable doubt all the elements of the offense charged. Every defendant is presumed to be mentally responsible. The defendant shall have the burden of going forward and proving by the greater weight of evidence that, as a result of mental illness or deficiency, he lacked capacity either to appreciate the wrongfulness of his conduct or to conform his conduct to the requirements of the law.” Section 7-ll-305(b), W.S.1977, Cum.Supp. 1985.
. Section 7-ll-305(c), W.S.1977, states:
“The designated examiners who examined the defendant pursuant to W.S. 7-242.3 [§ 7-11-303] or 7-242.4 [§ 7-11-304] are competent witnesses.”
. Under § 7-ll-304(a), W.S.1977:
"A person is not responsible for criminal conduct if at the time of the conduct, as a result of mental illness or deficiency, he lacked substantial capacity either to appreciate the wrongfulness of his conduct or to conform his conduct to the requirements of law.”