The issues in this appeal are: (1) whether the “year and a day” common-law rule in murder cases has been the law of New Jersey to date; (2) whether the rule should now be abolished or altered judicially; and (3), if the answers to (1) and (2) are in the affirmative, whether such change in the law should be applied retroactively to the defendant, who shot his victim September 17, 1972, with resulting death on November 19, 1973, and was convicted of murder. The common-law rule held that “[i]n order also to make killing murder, it is requisite that the party die within a year and a day after the stroke received, or cause of death administered * * *.” Blacksione Commentaries, Bk. IY*195.
The background facts in this ease are stated in the Appellate Division opinion, 148 N. J. Super, at 407-408. Defendant was first indicted, prior to the victim’s death, for assault with an offensive weapon and assault with intent to kill. After the death, defendant was indicted for murder. The indictments were tried together after defendant’s motion to dismiss the murder indictment on the basis of the year and a day rule was denied. He was convicted of second degree murder and of each of the assault charges. The Appellate Division on appeal affirmed the murder conviction but merged the assault convictions with that for the murder. 148 N. J. Super, at 414. The court accepted defendant’s contention that the year and a day rule became and remained a part of this State’s common-law jurisprudence but it held that the rule could and should be abolished judicially because it “does not conform to present-day medical realities, *248principles of equity or public policy.” Id. at 412-413. The court further held that since defendant had not relied on the common-law rule when he committed his lethal assault on the victim it was not unjust to apply the abolition of the common-law rule to defendant retroactively. Id. at 413-414.
We granted certification. 75 N. J. 540 (1977).
Our consideration of the issues does not bring a majority of the Court to a single view both on the matter of retention, abolition or modification of the year and a day rule and as to the effect of any such determination on the judgment under appeal. Four members of the Court would abolish the rule, but three of them would make such an adjudication prospective only, and would reverse the affirmance of the conviction by the Appellate Division. The fourth of those members would affirm the judgment of the Appellate Division. Two members of the Court would retain the rule and accordingly reverse the appellate judgment. The seventh member would modify the common-law rule so as to extend the period from a year and a day to three years, but would so hold prospectively only.
Accordingly, the judgment of this Court is one of reversal of the judgment of the Appellate Division and remand to the trial court with directions to dismiss the indictment for murder and to reinstate the conviction and sentence for assault with intent to kill.1
We proceed to explain the conclusions of a majority of the Court to the effect that (1) the year and a day rule was the heretofore prevailing common-law rule in this State; and (2) its abolition or modification at the present time should not operate retroactively to incriminate this defendant for murder.
*249I
There is no dispute between the parties that the year and a day rule was the common law of England prior to the adoption of the New Jersey State Constitution of 1776. The abundance and unanimity of authority on the point are manifest. Blackstone Commentaries, op. cit. supra,; III Coke, Inst. 47, 53 (4th ed. 1662); 1 East P. C. c. 5, p. 214, 3 Chitty, The Criminal Law *726 (1819); 1 Hawkins, P. C. c. 13 at 92 (Curwood ed. 1824). The leading modern texts are in accord. Wharton, The Law of Homicide, § 60 (1938); 2 Burdick Law of Crime § 423 (1946).
The transition of the pre-Revolutionary common law of England to the present era in this State was accurately described by Justice Heher in his dissenting opinion in Collopy v. Newark Eye and Ear Infirmary, 27 N. J. 29, 48-49 (1958) as follows:
The common law of England has a constitutional basis in our jurisprudence. It was provided in the State Constitution of 1776, Section XXII, ‘That the common law of England, as well as so much of the statute law, as have been heretofore practiced in this colony, shall still remain in force, until they shall be altered by a future law of the legislature; such parts only excepted, as are repugnant to the rights and privileges contained in this charter; * * *.’ The 1844 Constitution ordained, Article X, Section I, that ‘The common law and statute laws now in force, not repugnant to this constitution, shall remain in force until they expire by their own limitation, or be altered or repealed by the legislature.’ And the 1947 Constitution, Article XI, Section I, paragraph 3, declares that ‘All law, statutory and otherwise, all rules and regulations of administrative bodies and all rules of courts in force at the time this Constitution or any Article thereof takes effect shall remain in full force until they expire or are superseded, altered or repealed by this Constitution or otherwise.’2
However, the State argues that the year and a day rule is not now a part of the common law of this State for two *250reasons. First, although no court in this State prior to this case ever expressly declared the rule non-existent here, we should hold it not to have emerged from the Constitution of 1947 because it is “anachronistic as a result of advances in medical technology and expansions in the admissibility of expert witnesses.” Second, our statutory provisions concerning murder, N. J. 8. A. 2A:113-1 and 2, altered and abrogated the common-law year and a day rule by omitting any reference thereto. The latter rationale was the basis for the rejection of defendant’s motion to dismiss the indictment in the trial court. We agree with the Appellate Division’s dismissal of these contentions.
As to the first point made by the State, it does not constitute a tenable argument that the year and a day rule was not transmitted to our current common law by virtue of the constitutional provisions cited in the excerpt quoted above from the dissent in Oollopy, but rather a plea that the rule should now be abolished or altered. Whether or not the rule should be changed, it indubitably has persisted to the present day as the common law of England carried over by our several constitutions. See also Greenspan v. Slate, 12 N. J. 426, 433 (1953); In re Vince, 2 N. J. 443, 453 (1949); 2 Schlosser, Criminal Laws of New Jersey (3d ed. 1970) § 54:4 at 88.
The State’s second point does not impress us. Many common law crimes and concepts have survived the enactment of this State’s penal statutes. Our cases have consistently held that in enacting the murder statutes the Legislature created no new crimes but merely made distinctions, for the purpose of imposing different penalties between the most heinous and less aggravated grades of the crimes of murder. Thus, in Graves v. State, 45 N. J. L. 347 (E. & A. 1883), it was declared:
That which toas murder at the common law was, after the statute, still murder here, but the most flagitious species was designated as the highest degree and visited with the extreme penalty while all others were declared to constitute a lower class and to be punishable *251accordingly. When the Legislature, commendably simplifying the form of the indictment, provided that in charging the crime it should not be necessary to set forth the manner or means whereby the death was caused, but that it should be sufficient to charge that the defendant wilfully, feloniously and of his malice aforethought killed and murdered the deceased, it merely provided that in a charge of murder, a crime well understood and well defined in, the lato, it should he enough to, charge the crime in language sufficient to designate it. lid. at 358 (emphasis added)]
To the same effect see Brown v. State, 62 N. J. L. 666, 700 (E. & A. 1899), where the court stated that L. 1878, c. 235, § 107, created no new crimes but merely made a distinction with a view to the difference in punishment. As recently as State v. Brown, 22 N. J. 405 (1956), this construction was reaffirmed with regard to the current murder statutes, N. J. S. A. 2A:113-1; 113-2. The Court stated that these provisions
have not altered the nature of murder at common law; they are concerned only with the character of the punishment; the degrees do not constitute separate and distinct crimes, but merely grades of the same offense. Murder in either of the statutory degrees is murder at common law. lid. at 412]
The conclusion that the early New Jersey murder statutes were intended only to set the punishment for crimes whose elements were to be filled in by resort to fixed common-law principles is borne out by the titles of the early criminal statutes, each of which was entitled “An Act for the Punishment of Crimes,” see, e.g., Pat. 208, § 3 (1796); Rev. of 1846, Nixon's Digest at 161; L. 1898, c. 235, p. 791. The same purpose is apparent from the language of the respective statutes.
These considerations, coupled with the general principles that a statutory repeal of the common law will not be implied unless there is a clear repugnance between the common law and the statute, see State v. Western Union Tel. Co., 12 N. J. 468, 486 (1953); Clark and Marshall, Crimes, § 1.08 at 48 (6th ed. 1958), and that penal statutes are to be *252strictly construed, e.g., State v. Meiken, 10 N. J. 348, 352 (1952), suffice to demonstrate that the year and a day rule has not been abrogated by statute.
We conclude that the year and a day rule continued as New Jersey common law until and after the critical events in this case.
ri
Despite the fact that a majority of the Court believe that the year and a day rule should be abolished or modified, there is no majority in the Court for rendering any such determination effective retroactively so as to sustain the conviction of the defendant for murder.
In the first place, we regard the year and a day rule as a constituent element of the crime of murder, not a mere rule of evidence.3 The rule does not create a rebuttable presumption of absence of causal relation between assault upon and death of the victim. The rule renders conclusive the absence of culpability for murder once the period of a j^ear and a day has passed. That the rule may have evolved from early difficulties of proof of causal connection between assault and death remote in time from the assault, see III Colee Inst. c. vii at 53 (4th ed. 1670), does not derogate from the historic and present nature of the rule as one substantively immunizing the assaulter from liability for murder after lapse of the specified time. 3 Stephen, History of the Criminal Law of England at 7, 8 (1883), (“the law of England has laid down an arbitrary rule for criminal purposes on this subject. No one is criminally responsible for a death which occurs upwards of a year and a day * * * after the act by which it was caused.”)
*253Defendant argues that to apply a judicial abolition ox lengthening of the period of the year and a day rule to his case and consequently subject him to prosecution for murder would have the same effect as an ex post facto statute and constitute a denial of due process. The authorities support his position.
In Bouie v. Columbia, 378 U. S. 347, 84 S. Ct. 1697, 12 L. Ed. 2d 894 (1964), a case involving an unforeseen and broadening judicial construction of a State criminal trespass statute, the Court held that as a matter of due process the state court could not apply its decision retroactively. It reasoned:
[A]n unforeseeable judicial enlargement of a criminal statute, applied retroactively, operates precisely like an ex post facto law, such as Art I, § 10, of the Constitution forbids. An ex post facto law has been defined by this Court as one “that makes an action done before the passing of the law, and which was innocent when done, criminal; and punishes such action,” or “that aggravates a crime, or makes it greater that it was, when committed.” Calder v. Bull, 3 Dall. 386, 390, 1 L. Ed. 648, 650. If a state legislature is barred by the Ex Post Eacto Clause from passing such law, it must follow that a State Supreme Court is barred by the Due Process Clause from achieving precisely the same result by judicial construction. Cf. Smith v. Cahoon, 283 U. S. 553, 565, 51 S. Ct. 582, 586, 75 L. Ed. 1264, 1273. The fundamental principle that “the required criminal law must have existed when the conduct in issue occurred,” Hall, General Principles of Criminal Law (2d ed 1960), at 58-59, must apply to bar retroactive criminal prohibitions emanating from courts as well as from legislatures. If a judicial construction of a criminal statute is “unexpected and indefensible by reference to the law which had been expressed prior to the conduct in issue,” it must not be given retroactive effect. Id., at 61. (emphasis in original) 378 U. S. at 353-354, 84 8.. Ct. at 1702 (footnote omitted).
We believe the principle expressed in the foregoing decision is as fully applicable to the question whether a court altering a common-law criminal rule should allow its holding to render culpable as a given crime conduct which theretofore either was not a crime or constituted a crime of lesser degree. Illustrative is the decision in State v. Koonce, 89 *254N. J. Super. 169 (App. Div. 1965). The court there abolished the common-law rule of criminal law that a citizen could usé force against a uniformed policeman in order to resist an illegal arrest. However, the court made its determination prospective only. It stated: “It is uniformly recognized that it would be fundamentally unjust to render criminal, by an overruling decision, conduct which was not criminal when it occurred.” 89 N. J. Super, at 185. That language remains apropos in the present context notwithstanding defendant’s conduct here was criminal when it occurred. As indicated in the Bouie ease, supra, the inhibiting principle applies either where an innocent act would be rendered criminal or a criminal act would be rendered of greater or more serious consequence, by the subsequent judicial decision.
The indicated rationale is plainly applicable here. On September 18, 1973, the victim still alive, defendant was forever immune to prosecution for murder under the common law of New Jersey as it then stood. To render a present determination by this Court, abolishing the year and a day rule or extending the period thereof, effective to subject the defendant to liability for murder, would be fundamentally unfair in a jurisdiction devoted to the rule of law, if not offensive to concepts of due process, state and federal.
We are in disagreement with the Appellate Division’s reasoning that the Bouie and Koonce rationale is unavailing to this defendant because he was not relying on the common-law year and a day rule when he shot his victim. Actual reliance by a defendant on the prexisting state of the criminal law is not a prerequisite to invocation of the principle under consideration. While foreseeability of consequences and fair warning to the public are sometimes considered part of the philosophical basis for the ex post facto and related due process principles, cf. Bouie v. Columbia, supra, 378 U. S. at 359-361, 84 S. Ct. 1697, those principles are operative entirely without regard to whether the defendant in the particular case actually relied on the prior state of the criminal *255law at the time of the conduct in question. See Dobbert v. Florida, 432 U. S. 282, 292, 97 S. Ct. 2290, 53 L. Ed. 2d 344 (1977), reh. den. 434 U. S. 882, 98 S. Ct. 246, 54 L. Ed. 2d 166 (1977), quoting the definition of an ex post facto law stated in Beazell v. Ohio, 269 U. S. 167, 169, 46 S. Ct. 68, 70 L. Ed. 216 (1935), which is devoid of any allusion to reliance by the defendant upon the prior law. It may also be noted that actual reliance by defendant on prior law was not a factor in the decision in State v. Koonce, supra.
The judgment of the Appellate Division is reversed and the case is remanded to the trial court with directions to dismiss the murder indictment and reinstate the conviction and sentence for assault with intent to kill.
We hold the. conviction for assault with an offensive weapon to merge into that for assault with intent to kill. See State v. Best, 70 N. J. 86, 61-62 (1976) ; State v. Jamison, 64 N. J. 363, 380 (1974).
The views of the majority of the Court in Collopy were not to the contrary. See 27 N. J. at 43-45.
We disagree with the contrary view taken in Commonwealth v. Ladd, 402 Pa. 164, 166 A. 2d 501 (Sup. Ct. 1960) ; cf. People v. Snipe, 25 Cal. App. 3d 742, 102 Cal. Rptr. 6 (Ct. App. 1972).