(dissenting).
I.
I certainly do not think that we should substitute a trial by experts for a trial by the legal fact finders — either court or jury. It is exclusively within the province of the trier of fact to determine the legal sanity of a defendant. State v. Craney, 347 N.W.2d 668, 680 (Iowa), cert. denied 469 U.S. 884, 105 S.Ct. 255, 83 L.Ed.2d 192 (1984). However, I also do not think that when expert testimony establishes by a preponderance of the evidence that a defendant did not know right from wrong and the other available evidence establishes by a preponderance of the evidence that the defendant did not know right from wrong that we should uphold a trial court’s decision that the defendant did know right from wrong.
An expert psychologist, Dr. Zenian, testified, “My opinion is that the defendant was incapable of differentiating between right and wrong.” There was no doubt whatsoever in this expert’s opinion that the defendant was incapable of distinguishing right from wrong. Prior to trial another expert, Dr. Frederickson, testified, "... to a large degree, he [the defendant] did not understand or know what he was doing; did not know it was right or wrong and was incapable of forming intent.” Dr. Frederickson testified at trial that he had changed his mind, that he was confused, and that he didn’t know what he thought. I reproduce part of this expert’s remarkable testimony to illustrate his confusion:
Q. Isn’t it true that you were able to form a diagnostic impression regarding Mr. Wheeler’s psychiatric status as of December 18, 1984?
A. Yes.
Q. Isn’t it true, Doctor, that as a result of your evaluation of the defendant, and based upon your education and experience, you were able to come to the diagnostic conclusion that the defendant was incapable of forming specific intent on December 18, 1984?
A. I am not sure.
Q. Do you understand the question? Would it help to have the question read back to you?
A. I think I understand the question but—
Q. Well, let me rephrase the question, Doctor. Isn’t it true that in your letter to Judge Lavorato of May 28, 1985, you stated the following: “In summary, I think to a large degree he did not understand or know what he,” meaning Mr. Wheeler, “did not understand or know what he was doing did not know it was right or wrong, and was incapable of forming intent?” Is that what you wrote in your letter to Judge Lavorato?
A. Yes.
Q. Is that correct?
A. Is that correct what I wrote at that time?
Q. Yes, sir.
*66A. Yes.
Q. Have you evaluated the defendant since that date?
A. No.
Q. So you did write to Judge Lavorato that Mr. Wheeler was incapable of forming intent, isn’t that true?
A. To a large degree.
Q. Is it also true to a large degree that it is your opinion that on December 18, 1984, Mr. Wheeler did not understand or know what he was doing?
A. Yes, that was my opinion in my court letter.
Q. Isn’t it also true that it was your opinion in your letter to Judge Lavorato that on December 18, 1984, to a large degree Mr. Wheeler did not know if his actions were right or wrong?
A. Yes.
Q. Now, you have indicated that your diagnostic impression was that Mr. Wheeler’s primary problem was that he suffered from schizophrenia, paranoid type, sub-chronic chronic?
A. Yes.
Q. Is it also true that your diagnostic impression was that he suffered from delusional beliefs on December 1, 1984?
A. Yes.
Q. Isn’t it also your diagnostic impression that said delusional beliefs were the precipitating cause of the shooting that occurred at the Wheeler home on December 18, 1984?
A. I thought they played a role, yes. Q. Well, isn’t it true that your opinion that you expressed on May 28 that Mr. Wheeler to a large degree did not understand or know what he was doing, did not know it was right or wrong and was incapable of forming intent, those opinions were based upon your examination and your concept that he suffered from delusional beliefs?
A. Yes.
Q. Are you familiar with what is commonly known as the McNaughton Rule?
A. Yes.
Q. And you understand that that rule essentially says a person is insane if he is unable to form specific intent to understand the nature and quality of his acts or be able to distinguish right from wrong in relationship to those acts.
MR. THOMAS: Your Honor, I am going to object to that question.
MR. PIAZZA: Withdraw the question.
Q. Has your opinion changed since May 28th?
A. Yes, to some extent.
Q. Well, you have not evaluated the defendant since May 28th, have you?
A. No, but I reviewed his records and have done a lot of thinking since then.
Q. So you are saying to the Court that your letter of May 28th was incorrect?
A. I think partly, yes.
Q. What part is incorrect, Doctor?
A. I currently think that he was capable of understanding and knowing what he was doing.
Q. Okay. Let’s stop there. In your letter you indicate that to a large degree he did not understand or know what he was doing. Now, what specifically has changed your opinion from May 28th to today in that regard?
A. Basically just reviewing and doing a lot of thinking on the case.
Q. Well, you can point to any set criteria or any set factor which the Court can base its opinion on as to what changed your mind from May 28th to today with regard to whether or not he could understand or know what he was doing besides just thinking about it?
A. Even though he had delusional beliefs, after reviewing the case further I decided that that did not necessarily mean that he had to act on those delusional beliefs or that he wasn’t capable of knowing what he was doing or capable of knowing right from wrong.
*67Q. So are you saying today that you believe that he knew right from wrong on December 18th, 1984?
A. Yes, I think he knew what he was doing.
Q. Did he understand the nature or quality of his acts on December 18, 1984?
A. Yes.
Q. And you are saying today that he could tell right from wrong in relationship to those acts?
A. I think so.
Q. You think so. Do you know it one way or the other?
A. Well, I think he understood and knew that he was attempting to kill his father.
Q. Now, with regard to intent, has your opinion as Mr. Wheeler’s capability of forming intent also changed since May 28th?
A. Intent is a little more confusing to me. It seems to me that the basic issue kind of boils down to whether or not he was capable of controlling his behavior at that time. Q. What is your opinion?
A. I am not sure.
Q. You are not sure as to whether or not he could control his behavior on December 18, 1984?
A. Yes.
Q. You are not sure?
A. Yes.
Q. Does that mean yes, you are sure, or yes, you are not sure?
A. Yes, I am not sure.
Q. Now, can I presume that you informed the Court that your opinions have changed since May 28th? I mean, did you write Judge Lavorato another letter?
A. No, I didn’t.
Q. When did you change your opinions as to whether you could understand or know what he was doing, whether or not he knew it was right or wrong?
A. Basically over the past four or five days as I have been reviewing the case.
Q. But it is your considered opinion, Doctor, that you don’t know whether Mr. Wheeler could control his actions on the day of December 18, 1984, do you?
A. I’m not sure, yes.
Q. Let’s get back to this intent. Do you today have an opinion as to whether or not Mr. Wheeler could form specific intent to kill?
A. I’m not sure what you mean by specific intent.
Q. Okay. What did you mean on May 28th when you wrote that he was incapable of forming intent? What did you mean by that?
A. I guess I mean that — I’m not sure exactly what I meant.
Q. I didn’t hear that last answer.
A. I’m not sure exactly what I meant.
* * ⅜ >⅜ *
Q. In your letter of May 28th you also indicated the following: “Some psychiatrists would probably see this as total or full insanity.” Do you recall writing that?
A. Yes.
Q. Isn’t that still true?
A. I think so.
Q. So it would be your testimony that from your knowledge of the professional medical community some psychiatrists would view Mr. Wheeler’s condition on December 18, 1984, as total or complete insanity?
A. Yes.
Therefore, without reinterviewing the patient, this expert testified, at the most, that he was unsure. The majority, in affirming the trial court, places a heavy emphasis on Dr. Frederickson’s confused testimony. It quotes from Dr. Frederickson’s “final analysis;” it compares Dr. Frederickson’s early and later reports; it relies on Dr. Frederickson’s opinion on the defendant’s delusional beliefs. The trial court, in fact, concluded “the doctor [Frederickson] is uncertain as to a conclusion on the insanity issue.”
*68Aside from this testimony, the court looked to “the facts of the shooting itself, the act of fleeing the scene in [the defendant’s] father’s car, the immediate and subsequent evasive actions, the contents of the phone conversation with [the defendant’s] sister on the afternoon of the shooting,” in finding that the defendant knew that his action was legally wrongful. I do not think circumstantial evidence relating to defendant’s actions after the crimes took place should be accorded as much weight as here assigned by the trial court. Iowa Code section 701.4 (1985) provides, in part, that “a person shall not be convicted of a crime if at the time the crime is committed the person suffers from a diseased or deranged condition of the mind.... Insanity need not exist for any specific time before or after the alleged criminal act [emphasis added].” The only credible testimony given during trial to explain this later behavior was by the psychologist Zenian when he testified:
Q. Does the fact that subsequent to December 18th Mr. Wheeler placed the firearm in question or parts of the firearm in question underneath his bed have any bearing upon your opinion?
A. No, not substantially.
Q. Would the fact that Mr. Wheeler left the jurisdiction in an automobile and was ultimately apprehended in Bay Minnette, Alabama, have any bearing on your opinion?
A. No.
Q. Would the fact that Mr. Wheeler is currently cognizant of the legal ramifications of these proceedings and the alternatives which would be available if he were acquitted have any significant bearing upon your opinion and assessment of his psychiatric condition on December 18th?
A. No, it would have nothing to do with the way he was functioning on December 18th.
Q. Would it be true that during the course of your work as a clinical psychologist for Broadlawns Medical Center you have in fact met various defendants who are masking or making up the symptoms in order to fool the psychiatrist; does that occur?
A. Yes. We run across some defendants like that every now and then.
Q. Are you able to recognize that when it occurs?
A. I have to say that I have been wrong on a few occasions, but by and large this is a commonly anticipated maneuver or strategy by someone who is in rather dire straits and consequently we tend to make a special effort to evaluate that condition.
Q. Do you see that situation as a possibility in this case, Mr. Zenian?
A. Not hardly, no. I don’t think that Mr. Wheeler is feigning any symptoms or putting on any kind of an act to avoid the consequences of his acts at the time, back in December ’84.
If the court was basing its conclusion on Mr. Wheeler’s sanity primarily on acts that took place after the events in question, I do not see much of a consideration, for instance, of Mr. Wheeler’s unstable acts while in prison:
Q. [to Mr. Zenian] Are you familiar .with any erratic behavior that Mr. Wheeler has exhibited while incarcerated in the Polk County Jail?
A. Oh, yes. He has had several bouts of pretty unusual behavior.
Q. Would you describe some of those for the Court? Excuse me, strike that. First of all, has any of the behavior that he has exhibited while incarcerated been consistent with your diagnosis.
A. Yes, they could be components of a schizophrenic reaction.
Q. Could you describe for us any specific behavior that you are aware of that would in fact be consistent with your diagnosis?
A. Well, very generally, when we first had an opportunity to examine Mr. Wheeler during the early part of — correction, mid part of January ’84 and since then, he certainly had a very distraught appearance about him. He was very tense, would talk a mile a minute, would *69get on one particular topic and could not let go. He was very obsessed by a number of different thoughts. He had a great push of speech. On one occasion he — I think to dramatize some of this, it was felt necessary to put him in a solitary isolation even with medication. I believe at the time he was in such a frenzy of behavior he had to be put in restraints, I think what would commonly be referred to as a straight jacket; and he even, while he was in solitary, in a room which had absolutely nothing in it, a rubber room, a padded cell, managed to bash his head on a grating which is indented below the surface of the floor. You would have to make an extreme effort to injure yourself in a room like that, but managed to smash his forehead into that grating with considerable force. I think leaving some scars to this day. And a lot of other behaviors with regard to eating certain things and not others and, as I said, having to be placed in restraints and so on. These are all quite common characteristics of a schizophrenic person.
I do not think there is sufficient evidence to support the trial court’s conclusion that the defendant did not prove by a preponderance of the evidence that he was insane when he committed the killing.
II.
Even if the trial court did not find that the defendant had carried his burden in showing that he was incapable of distinguishing right from wrong at the time of the killing, it should have recognized that the State did not sustain its burden of proving that the defendant committed the crime of murder in the first degree. In a prosecution for first degree murder, the State is required to show beyond a reasonable doubt that the defendant killed with malice aforethought and in a willful, deliberate, and premeditated manner. Iowa Code § 707.2 (1985); State v. Blair, 347 N.W.2d 416, 419 (Iowa 1984). I do not believe the State carried its burden with respect to the elements of premeditation and deliberation.
In Iowa, proof of the diminished mental capacity of a defendant has been accepted to negate the elements of premeditation and deliberation. State v. Gramenz, 256 Iowa 134, 140, 126 N.W.2d 285, 290 (1964). Evidence of diminished responsibility is admissible as a defense in any crime which requires proof of specific intent as an element. State v. Barney, 244 N.W.2d 316, 318 (Iowa 1976).
The elements of premeditation and deliberation, in this case, were effectively negated by evidence of diminished capacity on the part of the defendant. Deliberation and premeditation may be shown by circumstantial evidence in one or more of the following ways: 1) evidence of planning activity of the defendant which was directed toward the killing; 2) evidence of motive which might be inferred from entire relationship between defendant and victim; and 3) evidence regarding the nature of the killing. State v. Freie, 335 N.W.2d 169, 172 (Iowa 1983); State v. Wilkens, 346 N.W.2d 16, 20 (Iowa 1984). Requisite premeditation and deliberation may be negated by evidence that the defendant, because of mental illness not amounting to insanity could not plan a killing in a way possible by our first degree murder statute. State v. Gramenz, 126 N.W.2d at 290.
In this case, the defendant may have had time to think on the matter before acting, and he may have willfully carried out the act. Surely, however, if we say the defendant knew the difference between right and wrong, it is not possible to say that the planning, the motive, or the manner of the killing are not sufficiently suffused with mental disturbance to negative the requirement that he killed “deliberately.” The uncontroverted testimony established that the defendant was acting under the belief that his father was sexually involved with a grade school acquaintance of the defendant. The gun was “hidden” only to the extent of placing it uncovered under a bed. The evidence did not reveal a “lying in wait” murder but rather a killing with such motive, planning and manner of carrying out that revealed a seriously ill mind. In *70People v. Wolff, 61 Cal.2d 795, 40 Cal.Rptr. 271, 288, 394 P.2d 959, 976 (1964), the court held that when a defendant did not have the mental capacity to “maturely and meaningfully reflect” upon the gravity of what he was going to do, this factor should be taken into account when deciding whether the murder should be classed as first degree murder. If we are not inclined to overturn the court’s conclusion that the preponderance of the evidence failed to establish insanity, I think we must find upon the facts and the law, that the evidence also failed to support the finding, m the circumstances of the defendant’s undisputed mental illness, that the murder was of the first degree. Rather, at the most, the evidence can only sustain a conviction of second degree murder.