This is аn appeal from the defendant’s convictions of manslaughter, homicide by motor vehicle, and operating to endanger. On July 16, 1977, at approximately 5:30 a.m., the defendant, Robert K. Jones, an off-duty Mansfield police officer, while driving his car on the mid-Cape highway in Barnstable, travelled in the wrong di *388 rection in the eastbound lane and collided head-on with an approaching van. As a result of the collision, two people in the van were killed instantly, and a third died on July 31, 1977. Indictments were returned charging the defendant with three counts of manslaughter; three counts of vehicular homicide caused by the operation of a motor vehicle negligently so as to endanger public safety (G. L. c. 90, § 24G); and operating to endanger (G. L. c. 90, § 24 [2] [a]). Prior to trial the defendant filed several motiоns to dismiss the indictments on multiple grounds. All the motions were denied. At trial before a jury in the Superior Court, the Commonwealth contended that the defendant was acutely intoxicated at the time of the accident. The defendant presented evidence that he was not criminally responsible because he was suffering from stage four dyssomnia (sleepwalking) at the time of the accident. Hе was found guilty on all counts and sentenced to concurrent terms in a house of correction. 1
On appeal to the Appeals Court, the defendant alleged eleven assignments of error concerning the denial of his motions to dismiss, procedures leading up to the indictments, and various events that occurred at trial. In a lengthy opinion, the Appeals Court affirmed the conviсtions.
Commonwealth
v.
Jones,
Of the eleven issues originally raised by the defendant, this opinion addresses in depth only those two issues concerning the relationship between the statutory crime of homicide by motor vehicle and the common law crime of involuntary manslaughter caused by the reckless operation of a motor vehicle.
*389 1. Implied Repeal.
The defendant first contends that the Legislature’s enactment of G. L. c. 90, § 24G, inserted by St. 1976, c. 227 (homicide by motor vehicle),
2
impliedly repealed the common law crime of involuntary manslaughter arising out of wanton or reckless opеration of a motor vehicle. Under G. L. c. 90, § 24G, homicide by motor vehicle may be committed in any one of three ways. The defendant may cause a death by operating under the influence of intoxicating liquor; by operating negligently; or by operating recklessly. The three ways are stated disjunctively and create separate and independent grounds for prosecution. A finding of ordinаry negligence suffices to establish a violation of the statute.
Fadden
v.
Commonwealth,
The crime of manslaughter is not defined by statute in this Commonwealth. Two distinct forms of manslaughter have arisen as the product of common law development. Only one of these — involuntary manslaughter — is at issue in this case. Involuntary manslaughter is defined as an unlawful homicide unintentionally caused by an act that constitutes such a disregard оf the probable harmful consequences to another as to amount to wanton or reckless con
*390
duct.
Commonwealth
v.
Campbell,
Before the enactment of G. L. c. 90, § 24G, in 1976, a defendant who had killed another person unintentionally by reason of his improper operation of a motor vehicle might have been prosecuted for any of a variety of misdemeanor offenses, such as driving so as to endanger, c. 90, § 24 (2) (a), 4 or for involuntary manslaughter, which carries a maximum penalty of twenty years’ imprisonment in State prison. G. L. c. 265, § 13. 5 The legislative history of § 24G indicates that prosecutors faced with this choice hesitated to proceed on a manslaughter theory, even when the facts so warranted, because of the reluctance of jurors to convict fellow drivers on such a serious сharge. See memorandum from Mr. Endicott Peabody to the Judiciary Committee of the Massachusetts General Court, dated March 29, 1976, regarding 1976 Senate Doc. No. 703. On the other hand, the penalties established for the misdemeanor of driving to endanger did not seem commensurate with the crime of causing a death. Id. From this history, it seems clear that the purpose of c. 90, § 24G, was to provide a middle ground *391 between the felony of manslaughter and the misdemeanor of driving so as to endanger. 6
The c. 90, § 24G, indictment returned in this case was framed exclusively under that portion of the statute which makes negligently operating to endanger culpable, and the defendant was prosecuted only on that theory. The defendant’s prosecution on the manslaughter indictment was predicated on his wanton or rеckless operation of a motor vehicle. It is the manslaughter conviction that the defendant contends is invalid. He points out, correctly, that one of the c. 90, § 24G, standards (causing the death of a person by operating “recklessly”) appears indistinguishable from the common law definitions of involuntary manslaughter based on reckless conduct. He argues from this that the Legislature intended the § 24G offense to be the sole offense applicable where death is caused by a defendant’s conduct in recklessly operating a motor vehicle, precluding any further prosecutions for involuntary manslaughter based on such conduct. Although conceding that this asserted legislative intent was nowhere made express, the defendant contends that the portion of § 24G basеd on recklessness is so inconsistent with the gravamen of involuntary manslaughter by motor vehicle as to effectively repeal the latter in part. 7
Bearing in mind the very strong presumption against implied repeal, see
Commonwealth
v.
Hayes,
2. Duplicitous Convictions and Double Jeopardy.
A second pretrial motion brought by the defendant sought dismissal of the c. 90, § 24G, indictment on the ground that it was duplicitous of the manslaughter indictment. The judge, relying on our decision in
Commonwealth
v.
Maguire,
In determining whether, on the basis of a single act, a defendant may be prosecuted and punished fоr two statutory or common law crimes, the long-prevailing test in this Commonwealth is whether each crime requires proof of an additional fact that the other does not.
Morey
v.
Commonwealth,
Applying the Morey test to the two homicide offenses of which the defendant was convicted, we conclude that each offense plainly requires proof of an additional fact that the other does not. A conviction of vehicular homicide under G. L. c. 90, § 24G, requires the operation of a motor vehicle upon a way or in a place to which members of the public hаve access; a conviction of manslaughter requires neither the use of a motor vehicle nor any element of public access. To convict of involuntary manslaughter, the Commonwealth must prove wanton or reckless conduct; to convict of vehicular homicide, no such proof is necessary. See Commonwealth v. Maguire, 313 Mass. 669, 671-672 (1943). The Morey standard thus is satisfied.
The defendant contends, nonetheless, that c. 90, § 24G, must be deemеd a lesser-included offense of manslaughter under the reasoning of
Costarelli
v.
Commonwealth,
Although we decline to hold that vehicular homicide is a lesser-included crime of manslaughter, we nonetheless conclude that in the present situation, which in fact did involve operation of a motor vehicle on a public way, the two offenses are sufficiently closely related so as to preclude punishment on both. See
Commonwealth
v.
Cerveny,
The trial judge thus erred in entering judgments of conviction of all three crimes.
9
The proper approach would
*395
have been to submit the three charges to the jury and, if guilty verdicts were returned on more than one, to dismiss the less serious charge or charges prior to entering a judgment of conviction and sentencing on the most serious crime.
10
As a result of the duplicitous convictions, only the convictiоn on the most serious crime of manslaughter is valid. See
Commonwealth
v.
Grasso,
The sentences imposed by the trial judge were not consecutive, but concurrent. When consecutive sentences on duplicitous charges have been imposed, the remedy ordered by this court has been to vacate both the conviction and sentence on the lesser-included offense, and to affirm that on the morе serious offense. See, e.g.,
Commonwealth
v.
White (No. 2),
To continue to distinguish between consecutive and concurrent sentences is to assume that only the fact of imprisonment, and not the fact of conviction, is the harm resulting from the erroneous allowance of duplicitous convictions. Yet, adverse collateral consequences of convictions do exist, even when only concurrent sentences are involved. Among the collateral consequences acknowledged by the Supreme Court and other courts in various double jeopardy contexts are the harsher treatment that may be accorded the defendant under the habitual offender statutes of some States; the possible impeachment by prior convictions, if the defendant ever becomes a witness in future cases; and, in some jurisdictions, less favorable parole opportunities. See
Benton
v.
Maryland,
3. As fоr the remaining issues raised by the defendant on appeal, we agree with the result reached by the Appeals Court, and any differences we may have as to the reasoning on particular issues are not significant enough to merit further discussion.
4. The case is remanded to the Superior Court. The judgments of conviction of the less serious offenses of homicide by motor vehicle, G. L. c. 90, § 24G, аnd negligently operating to endanger, G. L. c. 90, § 24 (2) (a), are to be vacated, and those complaints are to be dismissed. The judgments of conviction of manslaughter are affirmed.
So ordered.
Notes
On the manslaughter and homicide by motor vehicle convictions, the defendant received two and one-half year terms. On the operating to endanger conviction, the defendant was sentenced to a two-yеar term. All three sentences are to be served concurrently.
The act, entitled “An Act imposing certain penalties for causing the death of persons as the result of certain improper operation of motor vehicles,” provides, “Whoever, upon any way or in any place to which the public has a right of access, or upon any way or in any place to which members of the public have access as invitees or licensees, operates a motor vehicle in violation of paragraph (a) to subdivision (1) of section twenty-four of chapter ninety [operating under the influence], or so operates a motor vehicle recklessly or negligently so that the lives or safety of the public might be endangered, and by any such operation so described causes the death of another person shall be guilty of homicide by a motor vehicle and shall be punished by imprisonment in a jail or house of correction for not less than thirty days nor more than two and one-half years, or by a fine of not less than three hundred nor more than three thousand dollars, or both.”
Voluntary manslaughter, on the other hand, is an unlawful homicide intentiоnally caused, but occurring as a result of “a sudden transport of passion or heat of blood, upon a reasonable provocation and without malice, or upon a sudden combat.”
Commonwealth
v.
Campbell,
General Laws c. 90, § 24 (2) (a), as appearing in St. 1975, c. 156, § 1, reads in relevant part: “Whoever upon any [public] way . . . operates a motor vehicle recklessly, or operates such a vehicle negligently so thаt the lives or safety of the public might be endangered, . . . shall be punished by a fíne of not less than twenty dollars nor more than two hundred dollars or by imprisonment for not less than two weeks nor more than two years, or both.”
General Laws c. 265, § 13, as appearing in St. 1971, c. 426, provides in part: “Whoever commits manslaughter shall, except as hereinafter provided, be punished by imprisonment in the state prison fоr not more than twenty years or by a fine of not more than one thousand dollars and imprisonment in jail or a house of correction for not more than two and one half years.”
The maximum penalty for violations of c. 90, § 24G, is two and one-half years’ imprisonment and a $3,000 fine; for manslaughter, twenty years’ imprisonment, G. L. c. 265, § 13; and for driving so as to endanger, two years’ imprisonment and a $200 fine, G. L. c. 90, § 24 (2) (a).
It might be more accurate to say that the defendant claims that the new statute superseded the common law crime in part. We note, too, that any claim of supersession must be limited to cases in which death by motor vehicle occurred upon a public way or in a place to which the public had access. There is, of course, no such public place requirement for common law manslaughter.
The defendant points to decisions in other jurisdictions finding such an implied repeal. E.g.,
State
v.
London,
Although we say the judge “erred,” we have in mind that he was confronted with issues not yet reached by this court, and that in practical effect both the Commonwealth and the judge implemented to a great extent the legislative intent by (1) the charging of negligence (not recklessness) in *395 the vehicular homicide indictment, and (2) the imposition of concurrent sentences upon the several convictions.
The trial judge correctly refused to require the Commonwealth in advance of trial to choose on which chаrge it wished to proceed. The Commonwealth would not have been required to choose among the charges unless necessary to protect the substantial rights of the defendant. See
Fadden
v.
Commonwealth,
The Supreme Court has described the guarantee against double jeopardy as consisting of three separate constitutional protections. “It protects against a second рrosecution for the same offense after acquittal. It protects against a second prosecution for the same offense after conviction. And it protects against multiple punishments for the same offense.”
North Carolina
v.
Pearce,
