(temporarily assigned), concurring. Although I would modify the year and a day rule to expand the period to three years, I agree with the reasons set forth in the Court’s per curiam opinion against any retroactive abolition or modification of the rule to incriminate this defendant for murder.
In my view, the year and a day rule served a salutary purpose at common law. In the first place, as stated in III Coke Inst. e. vii at 53 (4th ed. 1670), it tended to weed out cases in which there was a probability that the ultimate demise of the victim was attributable to natural causes rather than to the remote assault. In the nature of things, the selection of an arbitrary period of time to settle remoteness was desirable, as otherwise difficult problems of proof as to causation could arise if death transpired five, ten or twenty years after the assault. Secondly, it would seem unjust and contrary to common expectations that a Sword of Damocles in the form of a potential prosecution for murder should hang over a defendant’s head for years, particularly when he would long before have likely been prosecuted and convicted for the assault. See Commonwealth v. Ladd, 402 *256Pa. 164, 166 A. 2d 501, 519 (dissenting opinion of Mus-manno, J.)
Notwithstanding the foregoing, the advance of medical science since the medieval era in which the year and a day rule originated suggests the desirability of extending the period substantially beyond a year and a day. Firstly, the ill or injured can be made to survive for longer periods of time. See In re Quinlan, 70 N. J. 10 (1976). Secondly, diagnostic skills relative to determination of causation have substantially improved. In view of these factors, too many felons who justly deserve prosecution for murder can escape such prosecution under the year and a day rule. The defendant before us may well constitute, an example.
Yet the policy considerations mentioned earlier herein still cogently argue for a fixed period after assault within which death of the victim should be required to occur in order to constitute the original assault the crime of murder. Although medical expertise has vastly improved there could still be formidable evidential disputes, for example where a victim of an assault died ten or more years thereafter from pneumonia, as to whether there was sufficient causal connection between the assault and the death to turn the assaulter into a murderer. In my view it would be unfortunate to have to permit the issues in such a case to be resolved by the fortuitous reaction of a jury to opposing medical experts. A fixed time requirement between assault and death seems to me the most practicable expedient to minimize such predicaments, although it must be admitted that causation problems can still persist even when death does transpire within whatever time period is fixed by law.
Ideally, the Legislature should fix a time period for the indicated purpose or decide that no time period is necessary. Until that body chooses to resolve the matter, this 'Court, having the responsibility of adjusting the common law in the light of developing social policy, should act on the matter. A fair balance of all the pertinent considerations suggests *257to me that the period should be fixed at three years.1 I would vote for such a rule to be made effective prospectively.
The California legislature' chose a three year and a day period for this purpose. West’s Anno. Cal. Stat (Penal) § 194 (1969).