Order
Per Curiam,
Judgments of sentence reversed and new trial granted.
Opinion by
Mr. Justice Jones in Support op the Order Pee Curiam:
On August 1, 1962, Dennis Vogel shot and killed two persons during the course of an armed robbery. Immediately thereafter, Vogel returned to his home, packed his car and, with his wife and infant child, drove to Canada for a previously planned vacation. On August 2, 1862, Vogel was arrested by Canadian officials in response to a radio communication from the Pennsylvania police. The police officers searched the trunk of Vogel’s car and found the fruits of the robbery—cash, money bags and green stamps.
At his trial, in the Court of Common Pleas of Clinton County, in February of 1968, Vogel pleaded not guilty by reason of insanity, producing in support of his insanity claim evidence of his discharge from the Air Force because of mental illness and the testimony of various lay and expert witnesses. No useful purpose would be served by a repetition of all of this voluminous testimony; it is sufficient that it be noted that, from Ms early teens, Vogel displayed erratic and often bizarre conduct. Illustrative thereof is the testimony of Vogel’s former wife that she interrupted a war game Vogel was playing, with M & M candies representing soldiers, “He liked the green ones, I don’t know why, but he had the greens on one side and the orange on the other side, and he would make all of the other colors move like troops to help the other side. Q. You mean like reserves or something like that? A. Yes, and so just for the fun I reached down and I grabbed an M & M and I popped it in my mouth and he got furi[6]*6ous at me because it wasn’t dead yet. Q. The M & M wasn’t dead yet? A. Yes, the M & M wasn’t dead yet. It was not a soldier that was killed, in other words.”
The defense offered the testimony of three eminently well-qualified psychiatrists to establish Vogel’s legal insanity. Once again, the testimony being quite lengthy, I will not repeat it but merely quote the doctors’ conclusions. Dr. Leslie R. Angus, the Assistant Superintendent of the Danville State Hospital, testified as follows: “A. My opinion is that he was unquestionably, legally insane at the time he was alleged to have committed this crime on August 1, 1962. Q. You say that without the slightest hesitation? A. Without the slightest hesitation.” Dr. Bernard J. Willets, the Assistant Superintendent and Clinical Director of Far-view State Hospital, treated the defendant for five and one-half years between the time of his arrest in 1962 to the time of his trial in 1968.1 The doctor summarized his testimony as follows: “In my opinion, Dennis Vogel was legally insane at that time [August 1, 1962].” Dr. Robert Sadoff, a privately-practicing psychiatrist from Philadelphia, who was also the Clinical Director of the Forensic and Diagnostic Hospital at Holmesburg Prison, testified as follows: “My opinion, based on the facts, and based on my examination of him, [is] that he was legally insane, at the time, on August 1, 1962.”
The Commonwealth offered no direct evidence which either rebutted or impeached any of the testimony as to Vogel’s insanity. Rather, the prosecution relied upon the presumption of sanity and the testimony of various witnesses as to the circumstances surrounding the robbery and killings. Such testimony was summarized [7]*7by the court below, in its opinion, as follows: “Defendant’s prior threats to kill the deceased Atwood [the manager of the store]; his debts and financial problems ; the day before the killing he was seen across the street looking over the Grant store; the acts took place after 12 o’clock noon after the store was closed; after the killings ransacking the safe, taking over |800 in cash and tailing Mrs. Eechel’s pocketbook, and other items from the store; throwing away a .22 calibre revolver purchased by him sometime before the killings; within an hour after the crime fleeing with his wife and child to Canada; warning his wife not to look into the trunk where he had placed most of the stolen items; as the police were coming into the restaurant in Canada where he and his wife had gone to eat, attempting to pass a large roll of bills to his wife and when she refused to take it, to place it in her blouse.”
The jury found Yogel guilty of armed robbery and on two counts of murder in the second degree, in spite of an adequate and comprehensive charge on the doctrine of felony murder. He was sentenced to serve ten to twenty years in prison for the armed robbery and for the first count of murder. He was further sentenced to life imprisonment on the second count of murder, the trial judge relying on the Act of June 24, 1939, as amended, December 1, 1959, P. L. 1621, §1, 18 P.S. §4701. The trial court dismissed Yogel’s motion for a new trial, and he now appeals from the judgments of sentence.
I will first deal with Yogel’s claim that Section 701 of The Penal Code, referred to above, is not applicable to a defendant charged with having committed multiple murders at or about the same time. Section 701 provides: “Whoever is convicted of the crime of murder of the second degree is guilty of a felony, and shall, for the first offense, be sentenced to undergo imprisonment by separate or solitary confinement not exceed[8]*8ing twenty (20) years, or fined not exceeding ten thousand dollars, or both, and for the second offense, shall undergo imprisonment for the period of his natural life.” (Emphasis added)
As employed in this statute, the term “second offense” means a subsequent murder, a murder which was committed after a conviction for a prior murder, and which was not part of the same transaction or occurrence which led to the first murder. Cf. Commonwealth v. Swingle, 403 Pa. 293, 169 A. 2d 871, cert. denied, 368 U.S. 862 (1961). In order to increase the punishment for a second offense of second-degree murder, a prior conviction for murder must precede the commission of the second murder. The sentence of life imprisonment which was imposed by the trial court, on the second count of murder, was incorrect.
Appellant’s second contention is that the trial court charged improperly on the burden of proving sanity.2 Specifically, it is urged that the prosecution should have had the burden of proving sanity beyond a reasonable doubt, as a fact necessary to constitute the crime of murder.
Three views presently exist as to the quantum of evidence which is required to rebut the presumption of sanity in a criminal case. Annot., 17 A.L.R. 3d 146 (1968).
In the federal courts, the sanity of the defendant must be proven by the prosecution beyond a reasonable doubt, once the issue has been properly raised.3 [9]*9Lynch v. Overholser, 369 U.S. 705, 82 S. Ct. 1063 (1962); Davis v. United States, 160 U.S. 469, 16 S. Ct. 353 (1895). The issue of sanity is treated as an element of the crime which the prosecution must prove once the question of sanity is contested. Apparently, this is also the position of twenty-two of the states. Annot., 17 A.L.R. 3d 146, 158-59 (1968). If viewed as an element of the crime, it might be argued that due process would require the prosecution to prove sanity beyond a reasonable doubt. In re Winship, 397 U.S. 358, 90 S. Ct. 1068 (1970). But see Powell v. Texas, 392 U.S. 514, 545, 88 S. Ct. 2145, 2160 (1968) (concurring opinion).
At the opposite end of the spectrum was the Oregon statute, which required a defendant to prove his insanity beyond a reasonable doubt. Ore. Comp. Laws, §26-929 (1940).4 This statute was held to be constitutional in the face of an attack upon it as being violative of a defendant’s right to due process of the laws. Leland v. Oregon, 343 U.S. 790, 72 S. Ct. 1002 (1952). In view of the apparent basis for the federal rule, i.e., that sanity is an element of the crime to be proven beyond a reasonable doubt, it is interesting to note that the majority in Leland specifically rejected that concept. Id. at 794, 72 S. Ct. at 1005.5
The third rule, applied in this Commonwealth and at least twenty-three other states,6 places the burden upon the defendant to prove his insanity “by a fair [10]*10preponderance of the evidence.” Commonwealth v. Carluccetti, 369 Pa. 190, 199, 85 A. 2d 391, 395 (1952). Inherent in this rule is the rationale that sanity is not an element of the crime but, rather, involves the ability to understand and comprehend the right and the wrong of the commission of the crime, a state of mentality which would render punishment by way of confinement in a penal institution futile and would require institutional confinement of the defendant for treatment rather than for punishment. Cf. Act of October 20, 1966, Spec. Sess. No. 3, P. L. 96, art. IV, §413, 50 P.S. §4413. In my view, insanity is a defense upon the proof of which an accused may avoid punishment for the crime committed. As was pointed out in the case of Durham v. United States, 214 F. 2d 862, 876 (D.C. Cir. 1954), “[o]ur collective conscience does not allow punishment where it cannot impose blame.”
In a jurisdiction which uses the “irresistible impulse” test to determine legal insanity, as redefined in Durham, id. at 874-75, the question of insanity, at the least, is closely connected with the question of whether the killing was intentional.7 It may be appropriate, in such a jurisdiction, that the burden of proof as to both should be the same, since they are both concerned with what is clearly an element of the crime —i.e., the intent to kill. In Pennsylvania, a person may be legally insane either if he is incapable of knowing what he was doing, or if he does know what he was doing but was incapable of judging that it was wrong to do so. Commonwealth v. Woodhouse, 401 Pa. 242, 164 A. 2d 98 (1960).
As indicated by the facts in the instant case, legal insanity in this Commonwealth may or may not bear on the question of intent. The prosecution presented [11]*11ample evidence that Vogel planned his crime, from which evidence intention might be inferred, bnt no evidence that Vogel could appreciate the character of his actions. An individual may intentionally kill someone, with malice aforethought, but be incapable of distinguishing right from wrong in so doing. Under such circumstances, the elements of murder would be met (Commonwealth v. Kirkland, 413 Pa. 48, 195 A. 2d 338 (1963)), but the individual’s legal insanity would properly necessitate a verdict of not guilty by reason of insanity. This is the type of situation which is demonstrated on the face of the instant record.
Appellant herein urges that this Court should overrule long-standing case law in Pennsylvania, and adopt the federal rule which would require the prosecution to prove sanity beyond a reasonable doubt, as an element of the crime. I cannot accept the premise that sanity is necessarily an element of every crime. To the contrary, I view insanity as being the basis upon which society offers treatment rather than punishment to one who has committed a crime. See H. Rome, M’Naghten, Durham and Psychiatry, 34 F.R.D. 93 (1964). Although every element of a crime can be established beyond a reasonable doubt, including the element of intent to do the act, insanity may still be asserted as a defense in Pennsylvania. Because of our abhorrence of punishing a man who could not evaluate his actions, if a defendant can demonstrate, by a fair preponderance of the evidence, that he was legally insane when he committed the crime for which he has been charged, he should be found not guilty by reason of insanity. See Commonwealth v. Updegrove, 413 Pa. 599, 198 A. 2d 534 (1964).
We specifically decline to adopt the federal rule as to the burden of proving sanity or insanity. The burden remains on the defendant to prove his insanity by a fair preponderance of the evidence.
[12]*12The final point made by the appellant presents a most important issue which I believe to be of first impression in this Court: may one be convicted of murder, even though the Commonwealth, relying on the legal presumption of sanity, presents no direct evidence to contradict or impeach the testimony of witnesses, lay and expert, who unequivocally testify that, at the time of the homicide, the accused was legally insane within the definition of legal insanity under the M’Naghten rule?
The trial court answered this question in the affirmative, relying upon prior decisions of this Court wherein, I suggest, a genuine conflict existed between the evidence presented by the Commonwealth and that of the defendant. E.g., Commonwealth v. Updegrove, 413 Pa. 599, 198 A. 2d 534 (1964); Commonwealth v. Carluccetti, 369 Pa. 190, 85 A. 2d 391 (1952). In the case at bar, the Commonwealth offered no affirmative direct evidence bearing on the question of the defendant’s sanity, i.e., the ability to distinguish between right and wrong at the time of the killings. The maximum that might be established by the testimony of the Commonwealth’s lay witnesses is that the actions of the defendant were apparently intentional. Such testimony did not serve to rebut the defendant’s proof of legal insanity, but merely established the circumstances of the crime, and the events leading to the apprehension of the defendant. Accordingly, the verdicts are not supported by the evidence and must be set aside. Commonwealth v. Hazlett, 429 Pa. 476, 240 A. 2d 555 (1968); Commonwealth v. Radford, 428 Pa. 279, 236 A. 2d 802 (1968); Commonwealth v. Tabb, 417 Pa. 13, 207 A. 2d 884 (1965). Cf. Act of June 15, 1951, P. L. 585, §1, 19 P.S. §871.
The defendant’s expert and lay witnesses clearly, unequivocally and without contradiction testified to [13]*13Vogel’s legal insanity before, during and after he committed this crime. The Commonwealth offered no evidence to rebut this testimony, but relied upon certain circumstantial evidence (introduced during its case in chief), from which it might be inferred that Vogel intended to commit the crime. However, the fact that an individual intends to commit an act does not necessarily indicate that he has the ability to determine whether it was right or wrong to do that act.
In this Commonwealth, we have refused to participate in the war of psychiatrists which some authorities fear. See K. Menninger, The Crime of Punishment (1966). Thus, the mere fact that the Commonwealth has offered no expert witnesses to rebut those of the defense does not itself preclude a jury from finding the defendant to have been sane, provided that there is some evidence to substantiate the conclusion that he was legally sane—i.e., that he could differentiate between right and wrong. Commonwealth v. Updegrove, 413 Pa. 599, 198 A. 2d 534 (1964) ; Commonwealth v. Carroll, 412 Pa. 525, 194 A. 2d 911 (1963) ; Commonwealth v. Lance, 381 Pa. 293, 113 A. 2d 290 (1955); Commonwealth v. Carluccetti, 369 Pa. 190, 85 A. 2d 391 (1952). If the rule did not include this proviso, then, as in the case at bar, a jury might return a verdict totally without evidentiary support of record.
The Commonwealth argues that the verdict is supported by the presumption of sanity, and that the jury may choose to disbelieve any witness. A verdict must be based upon evidence, and a presumption is not evidence. A verdict may not be based solely upon a presumption where there is evidence which credibly contradicts the presumption. Allison v. Snelling & Snelling, Inc., 425 Pa. 519, 229 A. 2d 861 (1967). See Commonwealth v. Wucherer, 351 Pa. 305, 41 A. 2d 574 (1945). The function of a presumption is to reach a [14]*14presumed conclusion of fact, in the absence of credible evidence to the contrary. Waugh v. Commonwealth, 394 Pa. 166, 146 A. 2d 297 (1958). When sufficient or adequate evidence is presented to prove legal insanity, the presumption of sanity disappears as a rule of law, and a verdict may not be based thereon. IX Wigmore on Evidence §2491 (3d ed. 1940).8
In the case at bar, the defendant produced evidence of legal insanity, sufficient and adequate in every respect, which was neither rebutted nor contradicted nor impugned, while the Commonwealth utterly failed to produce any evidence of legal sanity. Under such circumstances, the legal presumption of sanity is not sufficient to permit, in the face of the uncontradicted evidence of insanity, a finding of guilt. The instant record being devoid of any evidence which might support the verdict, such verdict cannot stand.
The judgments of sentence are vacated, and a new trial is granted.
Mr. Justice O’Brien joins in this supporting opinion.
Mr. Justice Roberts in Support op the Order Per Curiam :
While I agree that appellant is entitled to a new trial, I cannot agree with the refusal to place the burden on the Commonwealth of proving appellant’s sanity beyond a reasonable doubt. One of the most fundamental principles in our criminal law is that it is for the State to prove, beyond a reasonable doubt, all the elements of a crime. Equally fundamental is the principle that murder is not, in Mr. Justice Frankfurter's [15]*15words, merely “a muscular contraction resulting in a homicide.” Leland v. Oregon, 343 U.S. 790, 802, 803, 72 S. Ct. 1002, 1009 (1952) (dissenting opinion).1 For a defendant to be guilty of murder, the “muscular contraction” must be coupled with a mens rea—“malice aforethought express or implied.” Commonwealth v. Drum, 58 Pa. 9, 15 (1868). This mens rea is as much an element of the crime of murder as is the physical act of killing.
If mens rea, or intent, is an element of the crime of murder, the capacity to form that intent, i.e., legal sanity, must likewise be an element of the crime. Clearly “it is necessary, in order to prove the intent, to show that the perpetrator was capable of forming the requisite intent.” Bradford n. State, 234 Md. 505, 512, 200 A. 2d 150, 154 (1964). I therefore cannot agree with the assertion that “[a]n individual may intentionally kill someone, with malice aforethought,” even though he is legally insane, i.e., legally incapable of forming the intention. Legal sanity is an essential element of the crime of murder and must be an issue for the Commonwealth to prove beyond a reasonable doubt. See In re Winship, 397 U.S. 358, 90 S. Ct. 1068 (1970). [16]*16Thus I believe that the trial court was in error in the instant case when it charged the jury that the burden was on the defendant to prove by a preponderance of the evidence that he was not sane. This charge, in effect, required the defendant to disprove an element of the crime of murder and I do not believe this to be proper.
1 would adopt the rule which is now in effect in at least twenty-two of the States and in the federal courts. See cases cited in 17 A.L.R. 3d 158-59. These jurisdictions, taking for granted that most men are sane, do not initially require the prosecution to prove sanity, for it will be presumed. But if the defendant introduces evidence indicating that he is not sane, the presumption can no longer be relied upon by the State and the prosecution must prove sanity, as it must all other elements of the crime, beyond a reasonable doubt.2
Under the charge used in the instant case the jury could very well have had a reasonable doubt as to a defendant’s sanity, and hence his guilt, and yet have convicted him because they were charged that the defendant must prove he was not sane. Compare Brock v. United States, 387 F. 2d 254 (5th Cir. 1967) (granting new trial where the government produced only a single lay witness to rebut government psychiatrist’s testimony that defendant was not legally sane). I do not think we can or should permit such a verdict to stand. As Mr. Justice Harlan, speaking for the United States Supreme Court over seventy years ago, stated: “How, then, upon principle, or consistently with humanity, can a verdict of guilty be properly returned, [17]*17if the jury entertain a reasonable doubt as to the existence of a fact which is essential to guilt, namely, the capacity in law of the accused to commit that crime?” Davis v. United States, 160 U.S. 469, 488, 16 S. Ct. 353, 358 (1895).
I therefore concur only in the grant of a new trial.
Mb. Justice Pomeroy in Support op the Order Per Curiam :
I concur in the order granting a new trial, but deem it appropriate to make certain further observations as to the effect of the presumption of sanity and the burdens of proof and production in a case such as this.
According to the view this Court has expressed on past occasions, a presumption of law is not evidence nor should it be weighed by the factfinder as though it had evidentiary value. Bather, a presumption is a rule of law enabling the party in whose favor it operates to take his case to the jury without presenting evidence of the fact presumed. Tt serves as a challenge for proof and indicates the party from whom such proof must be forthcoming. When the opponent of the presumption has met the burden of production thus imposed, however, the office of the presumption has been performed; the presumption is of no further effect and drops from the case. See Watkins v. Prudential Insurance Co., 315 Pa. 497, 173 Atl. 644 (1934); Szmahl’s Estate, 335 Pa. 89, 6 A. 2d 267 (1939) ; Geho’s Estate, 340 Pa. 412, 17 A. 2d 342 (1941); Commonwealth v. Wucherer, 351 Pa. 305, 41 A. 2d 574 (1945); Waters v. New Amsterdam Cas. Co., 393 Pa. 247, 144 A. 2d 354 (1958); Waugh v. Commonwealth, 394 Pa. 166, 146 A. 2d 297 (1958) ; and Allison v. Snelling & Snelling, Inc., 425 Pa. 519, 229 A. 2d 861. (1967). See, also, 9 Wigmore, 3rd Ed. §2490 et seq. (1959).
The soundness of this understanding is supported by a consideration of the various grounds for recognition [18]*18of particular presumptions: the probability that the presumed fact is in the nature of things likely to be true; the procedural convenience of presuming, without proof, a fact frequently not put in issue; the fairness of allocating the burden of production to the party having superior access to the means of proof; and considerations of policy which lead the courts to favor one contention over another by giving it the benefit of a presumption. McCormick, Evidence, §309 (1954). The presumption of sanity reflects a common sense view that a man is more likely than not to be sane; speaking as it does to the generality of cases, the presumption is entitled to no evidentiary or probative weight when it is rebutted in a particular case. Quite simply, I understand the presumption of sanity to be a product of procedural convenience, eliminating the issue of sanity from the trial of the case unless and until some attempt is made by the defendant to raise the issue and rebut the presumption.
A further issue arises from the need to define the quantity of evidence which the opponent of a presumption must introduce in order to satisfy the burden of production thus placed upon him. In cases like that now before us, some courts have found that the defendant’s burden is met by the production of “some” or “any” evidence; others have held that the burden of production is met only by evidence which is fairly preponderant or by evidence adequate to sustain a juror’s reasonable doubt as to the fact presumed.1 In my view, it is most appropriate to require the defendant, if he would rebut the presumption, to produce competent evidence sufficient to create a reasonable doubt in the mind of the jury. Competent evidence may ultimately be found incredible by a jury, but credibility is of [19]*19course a fact issue which arises only after a case has been properly submitted to the jury. In the present case it is clear that the defendant’s evidence, consisting as it did of the unequivocal testimony of four well-qualified psychiatrists, was adequate to rebut the presumption of sanity regardless of the standard employed. Having produced competent testimony adequate to create a reasonable doubt as to his sanity, the defendant in my view met his burden of production, and the presumption of sanity, having been rebutted, disappeared from the case.2
A further, basic question remains as to the burden of persuasion on the issue of sanity. I realize that our case law has placed upon the defendant the burden of establishing his insanity by a preponderance of the evidence. This rule was accepted without question by the appellant in the case at bar, and the trial judge correctly so charged. Upon reflection, however, I see no reason why the Commonwealth should not have the same burden with regard to sanity, once that matter has been put in issue, as we have placed upon it as to all other facts necessary to support a guilty verdict. As has been noted by one leading authority, “. . . as to all these claims for exoneration [affirmative defenses such as insanity] their truth goes in final analysis to the guilt,—to the rightness of punishing the accused. Thus it seems inconsistent to demand as to some elements of guilt, such as an act of killing, that the jury be convinced beyond a reasonable doubt, and as to others, such as duress or capacity to know right from wrong, the jury may convict though they have such doubt. Ac[20]*20cordingly, the recent trend both in English and Amer-can decisions is to treat these so-called matters of defense as situations wherein the accused will usually have the first burden of producing evidence in order that the issue be raised and submitted to the jury, but at the close of the evidence the jury must be told that if they have a reasonable doubt of the fact on which the justification is based they must acquit.” McCormick, Evidence, at p. 684 (1954).
A similar conclusion is reflected in the American Law Institute’s Model Penal Code, §§1.12 and 4.03 (Prop. Official Draft, 1962). Section 1.12(1) provides that each element of an offense is to be proved beyond a reasonable doubt, the innocence of the defendant being assumed absent such proof. Section 1.12(2) provides that an affirmative defense such as insanity need not be disproved “unless and until there is evidence supporting such defense.” Thus the Code places the burden of production upon the defendant, but that burden having been met, the burden of persuasion lies with the prosecution.3
The burden which this approach would place upon the Commonwealth may be met by any competent evidence, including circumstantial evidence. But in the present case the Commonwealth produced no direct affirmative evidence to prove that the defendant was legally sane at the time of the murder; neither was [21]*21there any circumstantial evidence which tended to prove legal sanity, as distinguished from intent or design to carry out the robbery in the course of which the homicide occurred.
To summarize, I believe that the presumption of sanity relieves the Commonwealth of the necessity of establishing the defendant’s sanity, unless and until the defendant introduces evidence sufficient to create a reasonable doubt as to the existence of sanity. Such evidence having been here presented, the burden of persuasion that the defendant was sane was in my view properly with the Commonwealth. On the face of the record before us, the Commonwealth did not meet that burden. The jury’s verdict being thus not supported, the defendant ivas entitled to a new trial.