Commonwealth v. Ronchi ( 2023 )


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    SJC-13043
    COMMONWEALTH   vs.   PETER RONCHI.
    Essex.       October 13, 2022. - February 14, 2023.
    Present:   Budd, C.J., Gaziano, Cypher, Kafker, & Wendlandt, JJ.
    Homicide. Evidence, Prior misconduct, Pattern of conduct,
    Expert opinion, Intent. Intent. Practice, Criminal,
    Capital case, Argument by prosecutor, Instructions to jury,
    Jury and jurors, Deliberation of jury. Jury and Jurors.
    Indictments found and returned in the Superior Court
    Department on August 21, 2009.
    The cases were tried before David A. Lowy, J.
    Neil L. Fishman for the defendant.
    Marina Moriarty, Assistant District Attorney, for the
    Commonwealth.
    GAZIANO, J.    On the evening of May 16, 2009, the defendant
    repeatedly stabbed his nine months pregnant girlfriend, Yuliya
    Galperina, killing her and her viable fetus.     At trial, there
    was no dispute that the defendant had stabbed Galperina; the
    primary issue before the jury was whether the fatal stabbing had
    2
    been mitigated by heat of passion upon reasonable provocation so
    as to reduce the defendant's liability from murder to
    manslaughter.   The basis for the provocation, the defendant
    argued, was Galperina's (false) disclosure that he was not the
    father.
    A Superior Court jury convicted the defendant of two counts
    of murder in the first degree.   In this appeal, the defendant
    argues that the evidence was insufficient to support his
    convictions of murder in the first degree, on the ground that no
    rational juror could have found that the stabbings were not the
    result of a heat of passion upon reasonable provocation.      The
    defendant also argues that he cannot, as a matter of law, be
    held liable for the death of the full-term fetus because he did
    not stab or injure the fetus, who died due to loss of maternal
    blood circulation.    In addition, the defendant challenges
    certain of the judge's evidentiary rulings, statements in the
    prosecutor's closing argument, and the discharge of a
    deliberating juror.   The defendant also asks this court to
    exercise its extraordinary authority under G. L. c. 278, § 33E,
    to reduce the verdicts to manslaughter.
    For the reasons that follow, we affirm the defendant's
    convictions and, after a thorough review of the entire trial
    record, decline to allow relief under G. L. c. 278, § 33E.     We
    also take this opportunity to disavow our precedent on
    3
    reasonable provocation based on sudden oral revelations of
    infidelity, and, relatedly, lack of paternity.       See Commonwealth
    v. Schnopps, 
    383 Mass. 178
    , 180-182 (1981), S.C., 
    390 Mass. 722
    (1984).
    1.      Facts.   We recite the facts the jury could have found,
    reserving certain facts for later discussion of specific issues.
    a.      Commonwealth's case.   In May of 2009, Galperina was
    living in an apartment in Salem with her eight year old son and
    three year old daughter; the apartment was on the fifth floor of
    a two-building complex.      Galperina and the defendant had been
    dating for approximately two years.      She was nine months
    pregnant, with a due date of May 21 or 22, 2009; the defendant
    was the father.
    On Saturday, May 16, 2009, the defendant ate dinner and
    watched a movie at a friend's house in Gloucester.       He left at
    approximately 10 P.M.      The friend described the evening as
    ordinary and the defendant's demeanor as "pleasant" and
    "jovial."    Security surveillance footage at Galperina's
    apartment building showed the defendant entering the building at
    10:16 P.M. and reaching the fifth-floor hallway at 10:17 P.M.
    The defendant left Galperina's apartment approximately ninety
    minutes later, at 11:46 P.M.       A neighbor, who lived two
    apartments away from Galperina, had heard a scream sometime
    between 11:30 P.M. and midnight.
    4
    At around 7:20 A.M. on the morning of May 17, 2009, Alvaro
    Espinal-Martes took the elevator to the fifth floor to get a
    ride to work from his friend and coworker.    When the elevator
    door opened, he saw Galperina's distraught children in the
    hallway.   One of the children grabbed his hand and led him to
    Galperina's apartment.   Her body was on the living room floor,
    bloody and covered with a sheet.   Espinal-Martes brought the
    children to his friend's nearby apartment and called 911.
    First responders observed Galperina lying on her back next
    to a futon, covered in a sheet.    She had lacerations to her
    torso, and blood was splattered on the furniture, the floors,
    and the walls.   In the bathroom, police found a pair of blood-
    soaked pants on the floor and bloodstains on the sink, faucet,
    and toilet.
    An autopsy revealed that Galperina had sustained at least
    fifteen stab wounds, including wounds to the back of her head,
    upper chest, and back.   She died of blood loss from the multiple
    stab wounds to her neck and torso.   The fetus was full term and
    would have been capable of surviving outside the uterus.     The
    fetus had not been stabbed; the cause of death was "loss of
    maternal [blood] circulation due to stab wounds to the mother."
    On May 17, 2009, at approximately 4 P.M., the defendant
    approached a uniformed police officer outside a Norwalk,
    Connecticut, police station.   The defendant was sobbing and
    5
    asked the officer for help.    He told the officer that he had had
    a nightmare in which "he killed his eight-and-a-half-month
    pregnant girlfriend."     The defendant then explained to that
    officer, and others who had joined them, that it was actually
    not a nightmare at all.     The defendant said that he had killed
    his girlfriend in Salem, Massachusetts, with a knife, but had
    left her children unharmed.    He placed a blanket over Galperina
    so that her children would not see her when they awoke.     The
    defendant then drove to Norwalk and parked at a discount
    department store.   He left the knife he had used in the stabbing
    in his minivan, purchased a bicycle, and rode around until he
    reached a police station.     The defendant told the officers that
    he was not a "bad guy," and that he had stabbed his girlfriend
    because she told him that he was not the father of her baby.
    After the defendant was arrested, police obtained a warrant
    to search his house and the minivan.    They found a pair of
    bloodstained white sneakers and a jacket with bloodstains inside
    one of the sleeves in the defendant's living room.1    Inside the
    1 Police also found a ripped-up letter with the words "Last
    Will and Testament" in a waste basket in the defendant's home
    office. The letter was dated May 14, 2009, and stated: "I wish
    to leave all my assets to my two children. . . . It is my
    understanding and hope that the trust . . . will be of benefit
    to [them], as well, and they will be the sole beneficiaries of
    the trust." The torn-up pieces of paper did not include a
    bequest for the expected child. The defendant testified that he
    had planned to update his will, and introduced another note
    dated May 14, 2009, which said, "Once my unborn son . . . is
    6
    minivan, investigators found a bloodstained knife and sheath in
    the driver's door compartment.   There was occult blood on the
    driver's door handle and seatback.   Deoxyribonucleic acid (DNA)
    testing on the sneakers, the knife, and the sheath, according to
    the Commonwealth's expert, matched Galperina's genetic profile.
    The knife handle and the bloodstain on the jacket each contained
    a mixture of DNA from Galperina and the defendant.2
    b.   Defendant's case.   As stated, the theory of defense was
    that the defendant stabbed Galperina in the heat of passion
    following her announcement that he was not the baby's father,
    and that he lacked the intent for premeditated murder.
    The defendant testified in his own defense.   He said that
    he met Galperina in 2006 and they began an intimate
    relationship.   At first, they agreed to use birth control.    In
    2008, Galperina told the defendant that she was pregnant.     This
    born, I would like him to get a quarter of these assets, and to
    have this administered by his mother." The defendant also said
    that he intended to provide for the child by purchasing a life
    insurance policy.
    2 In Commonwealth v. Mattei, 
    455 Mass. 840
    , 851-853 & n.25
    (2010), this court concluded that testimony that a DNA "match"
    exists is inadmissible without accompanying statistical
    interpretation of the likelihood of that match by an expert.
    Here, however, the expert testified, without objection, that
    "[t]he major DNA profile matched the DNA profile of Yuliya
    Galperina." We conclude that, in these circumstances, there was
    no substantial likelihood of a miscarriage of justice from the
    expert's unobjected-to use of the word "match" without further
    discussion of the underlying statistics. See, e.g.,
    Commonwealth v. Seino, 
    479 Mass. 463
    , 469-472 (2018).
    7
    upset the defendant, because he did not think they were ready to
    have a baby, and they had agreed they would not.    The two split,
    and soon thereafter Galperina learned that she in fact was not
    pregnant.
    Galperina and the defendant reconciled, and then they
    decided to have a child together.    The defendant testified that
    he changed his mind because he "loved [Galperina] very much."
    He went with her to prenatal appointments, displayed an
    ultrasound image of the fetus in his living room, and purchased
    a changing table.   He also kept a file of things having to do
    with his expected child, and he had chosen a name for the child.
    The defendant said that he and Galperina had agreed to "raise
    the child as we were a married couple.   We were both going to
    participate in the raising of the child . . . equally."
    During the course of her pregnancy, the defendant and
    Galperina nonetheless had several disagreements concerning her
    parenting practices and, in particular, her use of natural and
    traditional remedies.    The defendant pointed out that she left
    her young children unattended, failed to dress them in clothing
    appropriate for the weather, and allowed them to play in the
    rear seat of a moving vehicle while they were not wearing
    seatbelts.    The defendant also disliked that Galperina brought
    her daughter to an unqualified healer to treat a learning
    disability.   Galperina consumed "all kinds of weird
    8
    concoctions," including large doses of raw apricot seeds, that
    the defendant believed were toxic and potentially harmful to
    their child.    Galperina refused to allow the defendant to take
    the baby to meet his family until the baby was three months old,
    because her ethnic tradition required that a newborn child be
    isolated from visitors for the child's protection.    As her due
    date approached, Galperina acquiesced to several of the
    defendant's demands; she promised to take the child to a
    conventional holistic pediatrician, and to permit State-mandated
    vaccinations.
    The defendant also testified that he usually visited
    Galperina on Saturday nights and carried a hunting knife for his
    own protection.   He believed that her apartment building was in
    a "potentially dangerous area," and had seen groups of young and
    "seedy looking" individuals gathered around the entrance to the
    building.   When he visited Galperina for the last time, he was
    carrying a knife in his coat pocket.
    On that evening, he arrived at around 10 P.M.     They
    discussed the pending birth, and Galperina said that she no
    longer wanted the baby to be vaccinated.    The defendant was
    annoyed that she was reneging on their agreement.    She further
    angered the defendant by telling him that she had paid one
    hundred dollars to the natural healer for the baby's care.      She
    added that she had ignored his advice and had consumed a large
    9
    number of apricot seeds, and she insisted that the baby could
    not visit with the defendant's family as a newborn.       These
    statements made the defendant "quite angry," and he raised his
    voice.   He announced that he was leaving because he was not
    being allowed to make "any decisions about the baby," and he put
    on his coat.    The defendant told Galperina, "I'm leaving you and
    I'll send you money."     She replied, "Don't even bother sending
    the money.     It's not your child."
    The defendant testified that he felt anger, rage, and
    betrayal.    He "lost it" and blacked out.      His next memory was
    being in the bathroom, covered in blood and holding a knife.
    "It was, like, waking up.    I had the knife in my hand and there
    was blood everywhere."     He removed his bloodstained pants,
    dressed in a pair of pants he found in a hamper, kissed
    Galperina, covered her up with a sheet, and left the apartment.
    The defendant introduced expert testimony to establish that
    the killing was mitigated by a fragile mental state.       Dr. Thomas
    Deters, a neuropsychologist, conducted a comprehensive
    examination of the defendant.     Deters interviewed the defendant
    a number of times, administered a battery of tests, reviewed
    police reports and statements, and interviewed the defendant's
    relatives and friends.     Deters noted that the defendant suffered
    head trauma as a young child and as an adolescent, as well as
    from playing soccer in college.        Multiple stressors affected the
    10
    defendant's mental functioning at the time of the stabbing;
    these included the recent death of his mother, his strained
    relationship with his brother, a loss of employment, isolation
    from his children, and Galperina's refusal to allow him to
    coparent.
    Deters diagnosed the defendant as suffering from numerous
    neurological impairments, including Asperger's syndrome, anxiety
    disorder, mood disorder, personality disorder, major depression,
    sleep disorder, and prefrontal lobe abnormalities.   As a result
    of these illnesses, Deters opined, the defendant was unable to
    act appropriately when confronted with a stressful situation.
    Deters believed that, at the time of the stabbing, the defendant
    had been unable to weigh the consequences of his actions or to
    appreciate the cruelty of his actions.   The defendant's mental
    impairments made him susceptible to an enraged response to
    provocation.
    In rebuttal, the prosecutor introduced testimony by Dr.
    Tali Walters, a forensic psychologist.   Based on her interview
    of the defendant, and her examination of the police reports and
    the defendant's statements, Walters testified that the defendant
    did not have a mental illness.   It was her opinion that he had
    no impairments that would affect his ability to reflect coolly,
    to premeditate, or to form an intent to kill.
    11
    2.   Prior proceedings.   In August of 2009, a grand jury
    returned indictments charging the defendant with two counts of
    murder in the first degree in connection with the deaths of
    Galperina and "Baby Boy Galperina."   Beginning on October 9,
    2012, the defendant was tried before a Superior Court jury.     The
    Commonwealth proceeded on theories of deliberate premeditation
    and extreme atrocity or cruelty for the death of Galperina, and
    deliberate premeditation for the death of her fetus.   On
    November 8, 2012, a Superior Court jury convicted the defendant
    of two counts of murder in the first degree, under each of the
    theories alleged by the Commonwealth.
    3.   Discussion.   The defendant argues that his convictions
    of murder in the first degree should be vacated because no
    rational juror could have found the absence of heat of passion
    upon reasonable provocation based on the revelation of his lack
    of paternity.   The defendant also maintains that his conviction
    for the death of the fetus cannot stand because the common-law
    rule of liability for the death of a viable fetus, see
    Commonwealth v. Cass, 
    392 Mass. 799
    , 805-807 (1984), is based on
    the direct infliction of prenatal injuries.   Accordingly, he
    contends, he cannot be liable for murder where the fetus died as
    a result of maternal blood loss.   The defendant further argues
    that the conviction was not supported by sufficient evidence,
    12
    because the Commonwealth did not prove an intent to kill the
    fetus.
    In addition, the defendant maintains that a number of other
    errors at trial mandate that he receive a new trial.    He
    challenges several of the judge's evidentiary rulings, including
    the exclusion of pattern evidence to demonstrate that Galperina
    told another intimate partner that he was not the father of
    another of her children; the denial of the defendant's motion to
    introduce expert testimony on his mental state, in reliance on
    Commonwealth v. Jaime, 
    433 Mass. 575
    , 577-578 (2001), and
    Department of Youth Servs. v. A Juvenile, 
    398 Mass. 516
    , 531-532
    (1986); and the denial of a motion to strike Walters's testimony
    due to its lack of scientific reliability.
    The defendant also asserts that the prosecutor's reference
    in her closing argument to "transferred intent" created a
    substantial likelihood of a miscarriage of justice, and that the
    conviction of murder of the fetus was predicated on an erroneous
    jury instruction that lessened the Commonwealth's burden to
    prove that the fetus had been viable.   In addition, the
    defendant argues that the judge erred in dismissing a
    deliberating juror.   Finally, the defendant asks us to exercise
    our extraordinary authority, pursuant to G. L. c. 278, § 33E, to
    reduce the degree of guilt in the interest of justice, due to
    the mitigating circumstances of a crime of passion.
    13
    a.    Heat of passion upon reasonable provocation.    The
    defendant contends that this was a case of manslaughter, not
    murder, and that no reasonable juror could have found, beyond a
    reasonable doubt, the absence of the mitigating circumstance of
    heat of passion upon reasonable provocation, based on the
    combination of Galperina's "extraordinary provocations" and his
    fragile mental state.
    An intentional killing that otherwise would be murder may
    be reduced to voluntary manslaughter where there are extenuating
    circumstances, such as "sudden passion based on provocation."
    See, e.g., Commonwealth v. Whitman, 
    430 Mass. 746
    , 753-755
    (2000), and cases cited ("Voluntary manslaughter is an
    intentional killing in the heat of passion as a result of severe
    provocation" [citation omitted]).   In general, words alone are
    not sufficient provocation to reduce the crime of murder to
    manslaughter.   Commonwealth v. Anderson, 
    396 Mass. 306
    , 314
    (1985).   "[V]erbal insults and arguments, even if obscene or
    hostile, cannot constitute sufficient provocation, for a
    reasonable person 'can be expected to control the feelings
    aroused' thereby" (citation omitted).   Commonwealth v.
    Estremera, 
    383 Mass. 382
    , 392 (1981).   See, e.g., Commonwealth
    v. Vatcher, 
    438 Mass. 584
    , 589 (2003) (eleven year old
    physically challenged victim's extended temper tantrum, "however
    frustrating, annoying, and even infuriating his behavior, . . .
    14
    did not rise to 'adequate provocation'"); Commonwealth v.
    Groome, 
    435 Mass. 201
    , 219-222 (2001) (victim's revelation that
    she had acquired immunodeficiency syndrome and probably had
    transmitted disease to defendant was insufficient to support
    instruction on voluntary manslaughter); Commonwealth v. Masello,
    
    428 Mass. 446
    , 449 (1998) (heated argument was insufficient to
    constitute adequate provocation); Commonwealth v. Seabrooks, 
    425 Mass. 507
    , 514 (1997), S.C., 
    433 Mass. 439
     (2001) (false
    accusation of crime was insufficient to establish adequate
    provocation); Commonwealth v. Burke, 
    376 Mass. 539
    , 542-543
    (1978) (defendant was not entitled to instruction on provocation
    where he told victim that he loved her, and she responded with
    expletive and words of rejection).
    An exception to this rule exists, however, "where the words
    convey inflammatory information to the defendant."   Commonwealth
    v. Mercado, 
    452 Mass. 662
    , 671 (2008).   "[T]he existence of
    sufficient provocation is not foreclosed because a defendant
    learns of a fact from a statement rather than from personal
    observation.   If the information conveyed is of the nature to
    cause a reasonable person to lose his self-control and did
    actually cause the defendant to do so, then a statement is
    sufficient."   Groome, 
    435 Mass. at 220-221
    , quoting Model Jury
    Instructions on Homicide 28-29 (1999).
    15
    An even more narrow exception is applicable where the words
    constitute a "peculiarly immediate and intense offense to
    [one's] sensitivities."   Commonwealth v. Bermudez, 
    370 Mass. 438
    , 440-442 (1976).   We have deemed a sudden oral revelation of
    infidelity inflammatory information sufficient to constitute
    such provocation.    See, e.g., Commonwealth v. LeClair, 
    445 Mass. 734
    , 741-743 (2006); Schnopps, 
    383 Mass. at 180-182
    .    Contrast
    Commonwealth v. Gulla, 
    476 Mass. 743
    , 748-749 (2017)
    (defendant's prior knowledge of infidelity precluded claim of
    sudden discovery).   See also 2 W.R. LaFave, Substantive Criminal
    Law § 15.2(b)(5), at 500 (2d ed. 2003) ("a sudden confession of
    adultery by a wife, or information from a third person that a
    wife has been unfaithful, has sometimes been held to constitute
    a provocation to the husband of the same sort as if he had made
    an 'ocular observation' of his wife's adultery").3
    To be sufficient to establish reasonable provocation, the
    words must comprise sudden knowledge; an actual confirmation of
    3 In some other States, a verbal revelation of infidelity
    falls within the general rule that mere words are insufficient
    to establish reasonable provocation. In those cases, reasonable
    provocation requires that a defendant catch the other spouse and
    the spouse's paramour in the act. See, e.g., Luch v. State, 
    413 P.3d 1224
    , 1230 (Alaska Ct. App. 2018) (common law requires
    defendant find spouse in very act of committing adultery);
    People v. Chevalier, 
    131 Ill. 2d 66
    , 76 (1989) (only discovery
    of parties in act of adultery or immediately before or after act
    will suffice as provocation); State v. Thomas, 
    169 Iowa 591
    , 598
    (1915) (adequate provocation existed where act of adultery
    committed in presence and sight of defendant).
    16
    a suspicion of infidelity is not sufficient.   See Schnopps, 
    383 Mass. at 181-182
     (new trial was required where judge declined to
    give instruction on manslaughter because there was conflicting
    evidence whether defendant had just learned of wife's infidelity
    or had known of it for months); Bermudez, 
    370 Mass. at 440-442
    (no instruction on reasonable provocation was warranted where
    defendant had been separated from wife for three weeks and she
    made hostile and "obscene" statements telling defendant of her
    infidelity when he went to visit her to see their baby, but
    holding that "[t]he existence of sufficient provocation is not
    foreclosed absolutely because a defendant learns of a fact from
    oral statements rather than from personal observation. . . .      A
    reasonable man can be expected to control the feelings aroused
    by an insult or an argument, but certain incidents may be as
    provocative when disclosed by words as when witnessed
    personally.   Therefore, we leave open the possibility that, in
    an appropriate case, testing the defendant's response on an
    objective standard, sufficient provocation may be found in
    information conveyed to a defendant by words alone").   Compare
    Mercado, 
    452 Mass. at 672
     (no reasonable provocation where
    defendant had suspected for some time that wife had been
    unfaithful); Commonwealth v. Andrade, 
    422 Mass. 236
    , 237-238
    (1996) (no reasonable provocation where defendant had suspected
    for several weeks that wife had been unfaithful, even though he
    17
    had confirmed his suspicion less than seven hours before killing
    her).
    Accordingly, based on our existing jurisprudence on
    manslaughter, the defendant had grounds upon which to argue that
    the Commonwealth failed to establish that there were no
    mitigating circumstances that would reduce the stabbing here
    from murder to manslaughter, see Bermudez, 
    370 Mass. at 440-442
    ,
    and the judge properly instructed on manslaughter due to heat of
    passion, see Commonwealth v. Brown, 
    387 Mass. 220
    , 227 (1982),
    quoting Commonwealth v. LePage, 
    352 Mass. 403
    , 419 (1967)
    (manslaughter instruction must be given where "any view of the
    evidence will permit a finding that the offence is manslaughter
    and not murder").   The defendant's argument before us, however,
    rests on viewing the evidence in the light most favorable to
    him, rather than, as we must consider it when analyzing a
    question of sufficiency, in the light most favorable to the
    Commonwealth.   See, e.g., Hrycenko v. Commonwealth, 
    459 Mass. 503
    , 510-511 (2011).
    Notwithstanding the testimony that the defendant
    highlights, the jury were free to disregard his explanation that
    "he lost it" upon hearing that he was not the father of the
    fetus.    See Commonwealth v. Ehiabhi, 
    478 Mass. 154
    , 166-167
    (2017).    The jury reasonably could have adopted the
    Commonwealth's theory that the defendant got into a heated
    18
    argument with his girlfriend, formed an intent to kill her and
    her fetus, and stabbed her multiple times in the area of her
    vital organs, in accordance with that plan.   See Commonwealth v.
    Burgess, 
    450 Mass. 422
    , 432 (2008) (deliberate premeditation
    matter of logical sequence not necessarily time).     These were
    questions of fact reserved for a fact finder properly instructed
    on the crimes of murder and voluntary manslaughter.     We discern
    no basis in this record to second guess the jury's
    determination.
    We also take this opportunity to address the question
    whether our jurisprudence on manslaughter should continue to
    recognize oral revelations of infidelity as a basis for
    reasonable provocation.   In Commonwealth v. Steeves, 
    490 Mass. 270
    , 292 n.12 (2022), we "express[ed] serious doubt about the
    ongoing viability of this legal principle, where it rests on the
    outmoded perception that '[t]he killing of a spouse (usually a
    wife) by a spouse (usually a husband)' is 'an acceptable
    response to the discovery of infidelity,' thereby 'reinforc[ing]
    male irrationality as normal, and legitim[izing] the view of
    women as property'" (citation omitted).   Likewise, in State v.
    Shane, 
    63 Ohio St. 3d 630
    , 637 (1992), the Supreme Court of Ohio
    observed that the doctrine "has its foundation in the ancient
    common-law concept that the wife is the property of the
    husband":   "[w]hen a man is taken in adultery with another man's
    19
    wife, if the husband shall stab the adulterer, or knock out his
    brains, that is bare manslaughter; for jealousy is the rage of a
    man, and adultery is the highest invasion of property" (citation
    omitted).   The court concluded that "[t]his archaic rule has no
    place in modern society."   
    Id.
    We conclude that the exception in the Commonwealth to the
    mere words rule for sudden oral revelations of infidelity has
    run its course.   The exception rests upon a shaky, misogynistic
    foundation and has no place in our modern jurisprudence.     Going
    forward, we no longer will recognize that an oral discovery of
    infidelity satisfies the objective element of something that
    would provoke a reasonable person to kill his or her spouse.
    By today's ruling, however, we do not foreclose the
    possibility of sufficient provocation caused by learning of
    other types of information of a "nature to cause a reasonable
    person to lose his self-control" (citation omitted).   Groome,
    
    435 Mass. at 220
    .   It is difficult, given the vagaries of human
    conduct, to delineate all of the exceptions to the general rule
    that mere words are insufficient to constitute reasonable
    provocation.   In each case, the trial judge must consider
    whether the particular information conveyed to the defendant was
    sufficient to warrant an instruction on voluntary manslaughter.
    See Commonwealth v. Felix, 
    476 Mass. 750
    , 756-757 (2017)
    (discussing judge's duty to provide instruction on reasonable
    20
    provocation where precipitating event would have provoked heat
    of passion in ordinary person); Commonwealth v. Camacho, 
    472 Mass. 587
    , 602 (2015) (instruction on reasonable provocation is
    warranted if there is evidence deemed legally sufficient to
    cause accused to lose self-control in heat of passion).     See
    also Commonwealth v. Pina, 
    481 Mass. 413
    , 422 (2019)
    (instruction on manslaughter is required if evidence, considered
    in light most favorable to defendant, would permit verdict of
    manslaughter, not murder).
    b.   Liability for death of viable fetus where fetus was not
    directly injured.   At common law, the destruction of a fetus in
    utero was not a homicide.    See Cass, 
    392 Mass. at 805
    .   The
    issue "debated at common law" was whether criminal liability
    "might rest on a defendant's injuring a fetus in utero, where
    the fetus was later born alive, and then died of the injury
    without further guilty intervention by the defendant."
    Commonwealth v. Edelin, 
    371 Mass. 497
    , 512 (1976).   See Dietrich
    v. Northampton, 
    138 Mass. 14
    , 15, 17 (1884) (discussing common-
    law "born alive" rule).
    In Cass, 
    392 Mass. at 799
    , the court addressed whether a
    viable fetus is a "person" for purposes of the statute on motor
    vehicle homicide.   See G. L. c. 90, § 24G (homicide by motor
    vehicle is defined, in part, as operating motor vehicle while
    under influence of intoxicating substances and by such operation
    21
    "caus[ing] the death of another person").    The court examined
    the foundation for the "ancient" rule that a fetus must be "born
    alive," and rejected this limitation to the statutory definition
    of a person.   See Cass, 
    supra at 805-807
    .   The dominant
    rationale for the rule, the court noted, was the impossibility
    of determining whether "the fetus was alive when the accused
    committed his act."   
    Id.
     at 806 & n.5.   The better rule, the
    court held, "is that infliction of prenatal injuries resulting
    in the death of a viable fetus, before or after it is born, is
    homicide."   
    Id. at 807
    .   See Commonwealth v. Lawrence, 
    404 Mass. 378
    , 383-384 (1989) (extending liability for death of viable
    fetus to charge of involuntary manslaughter).
    The defendant contends that "Cass does not apply to the
    circumstances at bar because the fetus did not suffer a prenatal
    injury."   The defendant emphasizes that the fetus was uninjured
    by the stabbing and died as a result of loss of maternal blood.
    In the alternative, he urges this court to overrule Cass as an
    unlawful usurpation of the Legislature's authority to define
    criminal liability.
    The defendant's contention that the fetus was uninjured by
    the stabbing of Galperina is strained at best.    Admittedly, none
    of the fifteen stab wounds was inflicted on or touched the
    fetus.   Nonetheless, the defendant committed an act of violence
    against a woman who was nine months pregnant, repeatedly
    22
    stabbing her in, among other areas, the torso, where the vital
    organs are located.    By ending the mother's life, he destroyed
    the viable fetus through the cessation of life-sustaining
    maternal blood flow.   See Cass, 
    392 Mass. at 807
     ("If a person
    were to commit violence against a pregnant woman and destroy the
    fetus within her, we would not want the death of the fetus to go
    unpunished").   See also Commonwealth v. Crawford, 
    417 Mass. 358
    ,
    359 (1994), S.C., 
    430 Mass. 683
     (2000) (upholding conviction of
    involuntary manslaughter where mother was killed by gunshot
    wound to face and viable fetus died of oxygen deprivation).
    Nothing in Cass, 
    supra at 806-807
    , or our subsequent cases,
    requires that a viable fetus suffer a direct traumatic injury
    such as a gunshot wound or a stab wound.
    The defendant also argues that we should overrule Cass as
    an inappropriate exercise of "raw judicial power."    Relying on
    the dissent by Justice Wilkins, he argues that Cass is flawed
    because the court usurped the Legislature's exclusive authority
    to define criminal offenses and what conduct is punishable under
    the criminal law.   The defendant appears to overlook Justice
    Wilkin's discussion of the court's expanded definition of the
    word "person" "in the construction of an exclusively statutory
    crime," motor vehicle homicide.    
    Id. at 809
     (Wilkins, J.,
    dissenting).    Here, the question is not the interpretation of a
    statutorily defined offense.    At issue in this case is the
    23
    common-law definition of murder, a matter within the sole
    jurisdiction of this court.     See Commonwealth v. Castillo, 
    485 Mass. 852
    , 865-866 (2020) (exercising court's authority to
    redefine homicide offense).     Accordingly, the defendant's
    argument concerning the purported violation of the separation of
    powers is unavailing.
    c.   Evidence of deliberate premeditation with respect to
    fetus.   The defendant also argues that the death of the fetus
    was "merely incident to and an unintentional byproduct of the
    death of Galperina."     He contends that no rational juror could
    have found that he specifically intended to kill the fetus.
    To convict a defendant of murder in the first degree on a
    theory of deliberate premeditation, the Commonwealth must prove
    that the defendant intentionally caused the death of the victim
    "after a period of reflection."     Commonwealth v. Chipman, 
    418 Mass. 262
    , 269 (1994).    "No particular period of reflection is
    required for deliberate premeditation to be found. . . .       The
    law recognizes that a plan to murder may be formed within a few
    seconds."   
    Id.
       See Model Jury Instructions on Homicide 46-47
    (2018) (key is sequence of thought process).
    In determining whether the Commonwealth met its burden to
    establish each element of the offense charged beyond a
    reasonable doubt, we rely on the familiar Latimore standard.
    See Commonwealth v. Latimore, 
    378 Mass. 671
    , 677-678 (1979).
    24
    "[The] question is whether, after viewing the evidence in the
    light most favorable to the prosecution, any rational trier of
    fact could have found the essential elements of the crime beyond
    a reasonable doubt."   
    Id. at 677
    , quoting Jackson v. Virginia,
    
    443 U.S. 307
    , 319 (1979).   Although a conviction may be based
    entirely on circumstantial evidence, and the inferences drawn
    need only be reasonable, not inescapable, see Commonwealth v.
    Rakes, 
    478 Mass. 22
    , 32, 45 (2017), a "conviction may not rest
    on the piling of inference upon inference or on conjecture and
    speculation," Commonwealth v. Lao, 
    443 Mass. 770
    , 779 (2005),
    S.C., 
    450 Mass. 215
     (2007) and 
    460 Mass. 12
     (2011), citing
    Commonwealth v. Swafford, 
    441 Mass. 329
    , 339–343 (2004).
    Considering the evidence before the jury in the light most
    favorable to the Commonwealth, we conclude that the evidence
    would have permitted a reasonable juror to find, beyond a
    reasonable doubt, that the defendant deliberately intended to
    kill the fetus.   By his own statements, the defendant was well
    aware of the correlation between Galperina's health and the
    health of the fetus.   Among other things, he excoriated her for
    consuming what he viewed as toxic amounts of apricot seeds while
    she was pregnant.   The defendant told the jury that he was
    furious at Galperina's revelation that he was not the father.
    Fueled by anger, he pulled a hunting knife from his coat pocket,
    removed the knife from its sheath, and stabbed her fifteen times
    25
    in the torso, the location of her vital organs, and in the back
    of the head and neck.    The jury reasonably could have inferred
    that the defendant knew that by killing a woman who was nine
    months pregnant, he would end the life of the viable fetus
    carried in utero.    See Commonwealth v. Whitaker, 
    460 Mass. 409
    ,
    419 (2011) (deliberate premeditation may be inferred from
    "nature and extent of a victim's injuries, the duration of the
    attack, the number of blows, and the use of various weapons").4
    d.     Evidentiary rulings.   i.   Exclusion of pattern
    evidence.    The defendant sought to introduce evidence that,
    while she was pregnant with her daughter, Galperina told a
    former boyfriend that he was not the baby's father.       The
    defendant argued that the evidence was admissible to show a
    pattern of misconduct, to corroborate his testimony that he had
    been "extraordinarily" provoked by Galperina, or to rebut the
    4 The judge imposed consecutive sentences for Galperina's
    death and the death of her fetus. The defendant contends that
    this sentencing scheme violated the prohibition against double
    jeopardy by imposing multiple punishments for the same offense,
    as well as the "the fundamental principle of the criminal law"
    that liability rests on a defendant's intent and the results of
    his or her actions. We discern no abuse of discretion. As
    discussed supra, the evidence before the jury would have allowed
    them to conclude beyond a reasonable doubt that the defendant
    was liable for the death of the fetus based on a finding that he
    specifically intended to kill the fetus. The judge had
    authority to impose consecutive sentences for the unlawful
    killings of a mother and her viable fetus. See Commonwealth v.
    Crawford, 
    417 Mass. 358
    , 359 (1994), S.C., 
    430 Mass. 683
     (2000).
    26
    suggestion that he was fabricating the reason for that
    provocation.
    Prior bad act evidence generally is inadmissible.      See
    Commonwealth v. Crayton, 
    470 Mass. 228
    , 249 (2014); Mass. G.
    Evid. § 404(b)(1) (2022).    It may be admissible, however, to
    demonstrate a common scheme, pattern of operation, absence of
    accident or mistake, identity, or motive.     Commonwealth v.
    Dwyer, 
    448 Mass. 122
    , 128 (2006); Mass. G. Evid. § 404(b)(2).
    It was the defendant's burden, as the proponent of the evidence,
    to establish, by a preponderance of the evidence (1) that the
    act occurred; (2) that the prior bad act evidence pertained to
    some relevant issue at trial; and (3) that the prior event and
    the circumstances of the crime charged had a uniqueness or
    particularly distinguishing pattern of conduct common to the
    current and former incidents.    See Commonwealth v. Leonard, 
    428 Mass. 782
    , 785-786 (1999).    A judge may exclude prior bad act
    evidence if its probative value is outweighed by the risk of
    unfair prejudice.     Commonwealth v. Almeida, 
    479 Mass. 562
    , 568
    (2018).   "Determinations of the relevance, probative value, and
    prejudice of such evidence are left to the sound discretion of
    the judge" and will not be disturbed absent clear error
    (citation omitted).    Commonwealth v. Bryant, 
    482 Mass. 731
    , 735
    (2019).
    27
    Following the defendant's motion, the judge conducted a
    voir dire hearing of the former boyfriend.    The former boyfriend
    testified that he had been annoyed by Galperina's frequent
    contact with her son's father, who maintained a regular presence
    in his son's life.   The former boyfriend asked Galperina "as a
    joke, 'Were you sleeping with him?'"     Galperina replied, "Yes,
    and you know, the child I'm carrying is his."     According to the
    former boyfriend, she said this once or twice "as a joke," and
    they both laughed.
    The judge then excluded the proffered evidence about
    Galperina's statements to the former boyfriend on three separate
    grounds.   First, he found that the prior comment did not
    establish a pattern (possibly because the testimony was that
    Galperina had been joking around, as compared to the volatile
    situation leading to her death).   Second, the judge found that
    the defendant was attempting to introduce the evidence for
    impermissible propensity purposes.     See Mass. G. Evid.
    § 404(b)(1).   The judge commented, "[B]ased on this proffer,
    anything that could be taken from it, if anything at all, and
    really, nothing can, would be a propensity inference."      Third,
    the judge found that the probative value of the statement was
    substantially outweighed by the risk of undue prejudice.      We
    discern no abuse of discretion in the judge's decision to deny
    the introduction of the prior bad act evidence.
    28
    The judge also denied the defendant's request to extend
    Commonwealth v. Adjutant, 
    443 Mass. 649
    , 664 (2005), and to
    allow the admission of Galperina's statement as character
    evidence.     See 
    id. at 650, 663-664
     (where issue of self-defense
    is raised and identity of first aggressor is in dispute, judge
    may allow introduction of evidence of specific incidents of
    violence initiated by victim even if incidents were unknown to
    defendant).    The defendant argues that "[t]here is no reason why
    the same rule should not adhere here -- where the victim had a
    pattern of making identical extraordinarily provocative
    statements."     Adjutant establishes an exception to our general
    rule prohibiting evidence of a person's character "to prove that
    on a particular occasion the person acted in accordance with the
    character or trait."     See Mass. G. Evid. § 404(a)(1).   "Our
    decision in the Adjutant case is specifically limited to
    situations where the defendant claims self-defense . . . ."
    Commonwealth v. Benoit, 
    452 Mass. 212
    , 228 (2008).     See Camacho,
    
    472 Mass. at
    596 n.12 (Adjutant rule is not applicable to
    defense of another).     We decline the defendant's invitation to
    extend the holding in Adjutant beyond its narrow exception.
    ii.     Exclusion of opinion testimony by defense expert.
    Prior to the testimony by Deters, the defendant's psychological
    expert, the judge reminded the attorneys that he intended to
    enforce this court's rulings in Jaime, 433 Mass. at 577-578, and
    29
    Department of Youth Servs., 
    398 Mass. at 531-532
    .   "The purpose
    of this limitation on expert witness testimony is to prevent the
    proponent of the opinion from 'import[ing] inadmissible hearsay
    into the trial.'"   Commonwealth v. Piantedosi, 
    478 Mass. 536
    ,
    543 (2017), quoting Commonwealth v. Goddard, 
    476 Mass. 443
    , 448
    (2017).
    Under that precedent, an expert's opinion may be based on
    "(a) facts observed by the witness or otherwise in the witness's
    direct personal knowledge; (b) evidence already in the record or
    that will be presented during the course of the proceedings,
    which facts may be assumed to be true in questions put to the
    witness; and (c) facts or data not in evidence if the facts or
    data are independently admissible in evidence and are a
    permissible basis for an expert to consider in formulating an
    opinion."   Mass. G. Evid. § 703.   See Commonwealth v. Barbosa,
    
    457 Mass. 773
    , 784-785 (2010), cert. denied, 
    563 U.S. 990
     (2011)
    (expert was prohibited from informing jury during direct
    examination about facts and data that were not in evidence, but
    such testimony would have been admissible with proper witness or
    with foundation that expert considered in forming opinion);
    Department of Youth Servs., 
    398 Mass. at 532
     ("thrust of [our]
    rule is to leave inquiry regarding the basis of expert testimony
    to cross-examination").
    30
    The defendant objects to the judge's ruling that precluded
    Deters from testifying on direct examination to facts that were
    not in evidence, but upon which he had relied to form the basis
    of his opinion.   The defendant argues that the judge's decision,
    which fully comported with the rules of evidence concerning
    expert opinion testimony, undermined Deters's testimony "by
    impeding its narrative flow and calling into question its
    credibility and reliability."   The defendant maintains that the
    exclusion of certain of Deters's proffered testimony violated
    his right to a fair trial and to present a complete defense.
    We do not agree.    The judge's decision to exclude
    statements by Deters about the basis of his knowledge, where the
    facts upon which Deters relied were not in evidence, did not
    deprive the defendant of the ability to present a full defense.
    See Piantedosi, 478 Mass. at 543.   "A defendant's right to
    present a full defense . . . is not without limits . . . , and
    as a general rule, does not entitle him [or her] to place before
    the jury evidence normally inadmissible" (quotation and
    citations omitted).    Commonwealth v. Chappell, 
    473 Mass. 191
    ,
    204 (2015).
    Deters testified to having reviewed thousands of pages of
    discovery interviewing the defendant for twenty-nine hours and
    conducting batteries of neurological testing, having interviewed
    the defendant's family members, and having reviewed the
    31
    substance of the defendant's medical history.    Deters also
    referenced, as facts already in the record that underlay the
    bases of his opinion, the defendant's statements on direct and
    cross-examination, and the testimony of the defendant's brother,
    daughter, and ex-wife; an acquaintance; and a business
    associate.    The direct examination of Deters included details
    concerning the defendant's medical history, educational
    background, career, major bouts of depression, panic attacks,
    sleep dysfunction, social isolation, stressors, and
    abnormalities of his prefrontal lobe.
    iii.     Motion to strike certain testimony by Commonwealth's
    expert.   Walters, the Commonwealth's psychological expert,
    testified that the defendant was not mentally ill.    The
    defendant moved to strike her opinion testimony on the ground
    that she did not frame her opinion as being held to a reasonable
    degree of psychological certainty.    The judge denied the motion.
    He noted that, in the "ballistics case" -- Commonwealth v. Pytou
    Heang, 
    458 Mass. 827
    , 848-849 (2011) -- this court required that
    testimony be framed in that manner but has not done so in "any
    other situation."    The defendant argues that this decision was
    error, because it "gave Walters'[s] opinion an air of
    certitude."
    Because the defendant objected, we review for prejudicial
    error and consider whether there was a reasonable possibility
    32
    that the error contributed to the guilty verdicts.   Commonwealth
    v. Carriere, 
    470 Mass. 1
    , 7 (2014).
    A witness "qualified as an expert by knowledge, skill,
    experience, training, or education" may testify to an opinion if
    to do so would be helpful to the jury's understanding of the
    evidence "or to determine a fact in issue."   Mass. G. Evid.
    § 702.   See Commonwealth v. Hinds, 
    487 Mass. 212
    , 217 (2021)
    (role of expert witness is to help jurors understand evidence
    that lies outside their common experience).   "[E]xpert witness
    testimony may be excluded as not probative of a material fact in
    dispute and thus of no assistance to the jury when it amounts to
    a mere guess or conjecture."   Mass. G. Evid. § 702 note.    See
    Kennedy v. U-Haul Co., 
    360 Mass. 71
    , 73-74 (1971) ("A mere guess
    or conjecture by an expert witness in the form of a conclusion
    from basic facts that do not trend toward that conclusion any
    more than toward a contrary one has no evidential value").      A
    decision to admit or to exclude expert testimony falls within
    the sound discretion of the trial judge and will not be
    disturbed unless it is an abuse of discretion.   See Commonwealth
    v. Fitzpatrick, 
    463 Mass. 581
    , 603 (2012).
    In general, no threshold level of certainty is required of
    an expert before the expert's opinion may be admitted at trial.
    See Commonwealth v. Torres, 
    469 Mass. 398
    , 407 (2014) ("expert
    opinion that is not definitive but expressed in terms of
    33
    observations being consistent with a particular cause, or words
    of similar effect, does not render the opinion inadmissible on
    the ground that it is speculative" [quotations and citation
    omitted]); Commonwealth v. Nadworny, 
    396 Mass. 342
    , 359-360
    (1985), cert. denied, 
    477 U.S. 904
     (1986) (pathologist's
    inability to testify to cause of death to reasonable degree of
    medical certainty did not render opinion inadmissible as
    speculative).   Cf. United States v. Mornan, 
    413 F.3d 372
    , 381
    (3d Cir. 2005) (there is "nothing magical about the phrase, 'to
    a reasonable degree of scientific certainty'"); United States v.
    Cyphers, 
    553 F.2d 1064
    , 1072-1073 (7th Cir.), cert. denied, 
    434 U.S. 843
     (1977) (no requirement that expert's testimony be
    expressed in terms of reasonable scientific certainty).
    Undoubtedly, the phrase "reasonable degree of scientific
    certainty," or other forms of that phrase, is "a useful
    shorthand expression . . . helpful for forestalling challenges
    to the admissibility of expert testimony" (citation omitted).
    Anderson v. Paulo, 
    74 Mass. App. Ct. 635
    , 641 (2009).     See
    Commonwealth v. Roberio, 
    428 Mass. 278
    , 280 (1998), S.C., 
    440 Mass. 245
     (2003) (psychologist testified to reasonable degree of
    scientific certainty that defendant suffered from three mental
    diseases or defects).   "[C]are must be taken," however, "to see
    that the incantation does not become a semantic trap and the
    34
    failure to voice it is not used as a basis for exclusion"
    (citation omitted).    Anderson, 
    supra.
    The defendant contends that Pytou Heang, 
    458 Mass. at
    848-
    850, mandates that "subjective expert opinion" be presented to a
    reasonable degree of certainty.    We disagree.    In that case, we
    discussed a significant challenge to the admissibility of
    forensic ballistics testimony in light of concerns "about both
    the lack of a firm scientific basis for evaluating the
    reliability of forensic ballistics evidence and the subjective
    nature of forensic ballistics comparisons."       
    Id. at 837
    .   We
    offered guidelines "to ensure that expert forensic ballistics
    testimony appropriately assists the jury in finding the facts
    but does not mislead by reaching beyond its scientific grasp."
    
    Id. at 846-847
    .   The guidelines included a requirement that the
    expert's opinion be offered to a "reasonable degree of ballistic
    certainty."   
    Id. at 848
    .   Noting that other jurisdictions had
    come to different conclusions regarding the admissibility of
    such evidence, we struck a "middle ground" by permitting the
    introduction of an opinion that a match existed to a reasonable
    degree of ballistics certainty.    
    Id. at 850
    .
    Accordingly, we discern no prejudicial error arising from
    the judge's decision to deny the defendant's motion to strike
    Walters's testimony.    We also decline to extend our decision in
    Pytou Heang to encompass all expert opinion testimony.
    35
    e.   Prosecutor's closing argument.   i.   Transferred intent.
    As discussed, the defendant argues that a new trial is required
    because "no rational juror could have . . . found, beyond a
    reasonable doubt, that the defendant deliberately premeditated
    and specifically intended the death of the fetus."   He also
    argues that the prosecutor improperly raised the theory of
    transferred intent in her closing argument, in an effort to
    disguise the Commonwealth's lack of evidence as to the
    defendant's intent.
    The Commonwealth did not seek an instruction on transferred
    intent, see generally Commonwealth v. Taylor, 
    463 Mass. 857
    , 863
    (2012), with respect to the charge for killing the fetus.
    Nonetheless, in her closing argument, the prosecutor suggested
    that the jury infer that the defendant intended to kill the
    fetus with deliberate premeditation based on the attack on
    Galperina.   She argued:
    "And again, I don't want to tell you what premeditation is;
    the judge will instruct[] you on it. But I'd suggest to
    you that from the evidence that you heard, the Commonwealth
    has proven premeditation. As it relates to [Galperina] and
    her child, the intent that the judge will instruct you
    about is whatever intent you find is the intent that can be
    transferred to [Galperina's] child."
    Because the defendant did not object to these statements, we
    review to determine whether any error created a substantial
    likelihood of a miscarriage of justice.   See Commonwealth v.
    Wright, 
    411 Mass. 678
    , 681 (1992), S.C., 
    469 Mass. 447
     (2014).
    36
    We analyze the prosecutor's statement "in light of the
    entire argument, as well as in light of the judge's instruction
    to the jury and the evidence at trial" (quotation and citation
    omitted).    Commonwealth v. Raposa, 
    440 Mass. 684
    , 694 (2004).
    The single passing reference to transferred intent consisted of
    one line in a closing argument that occupied twenty-six pages of
    transcript.    The judge instructed the jury, before closing
    arguments were presented, that "the lawyers will, at some point
    in time, in order to structure their closing, inevitably be
    referencing the law.    I will instruct you on the law.     You must
    accept the law as I instruct you, whether you agree with that
    law or not."
    In his final charge, the judge instructed that it was his
    responsibility to "teach [the jurors] the law that applies to
    the case."     He also explained that the Commonwealth was required
    to prove, beyond a reasonable doubt, that the defendant
    deliberately premeditated the deaths of both Galperina and the
    fetus.   The judge emphasized, "There are two separate
    indictments.    One indictment alleges the murder of [Galperina],
    and one indictment alleges the murder of the fetus.       You must
    consider these indictments separately and the Commonwealth has
    the burden of proving each element of the indictment or its
    lesser included offenses beyond a reasonable doubt."       See
    Commonwealth v. Williams, 
    450 Mass. 645
    , 651 (2008) (jury are
    37
    presumed to follow judge's instructions).     Given the passing use
    of the term "transferred intent," its vagueness in the context
    of the closing argument as a whole, and the judge's instructions
    about the nature of closing arguments, we discern no substantial
    likelihood of a miscarriage of justice.
    ii.   Statement that mere words cannot establish reasonable
    provocation.    The defendant contends that the prosecutor
    "wrongly" told the jury that mere words cannot furnish the
    provocation necessary for manslaughter.     In her closing, the
    prosecutor stated that "mere words are not enough, so that when
    [Galperina] says to [the defendant], 'It's not your baby,' the
    Commonwealth would say to you, mere words are not enough."        She
    added that "[t]he court will instruct you on that, so I'm not
    going to tell you what those words mean."
    The defendant was not prejudiced by these statements.         The
    judge instructed that "[m]ere words, no matter how insulting or
    abusive, standing alone, do not constitute reasonable
    provocation."   See Model Jury Instructions on Homicide, supra
    at 77.   He explained:   "[T]he existence of sufficient
    provocation is not foreclosed because a defendant learns of a
    fact from a statement rather than from personal observation.       If
    the information conveyed is of the nature to cause a reasonable
    person to lose his self-control and did actually cause [the
    defendant] to do so, then a statement is sufficient."     See Model
    38
    Jury Instructions on Homicide, supra.     We presume that the jury
    followed the judge's instructions.     See Commonwealth v. Bins,
    
    465 Mass. 348
    , 367-368 (2013) (possible confusion from
    prosecutor's misstatement of law was remedied by judge's final
    charge).
    f.     Instruction on viability.   In accordance with
    Commonwealth v. Crawford, 
    430 Mass. 683
    , 691 (2000), the judge
    instructed the jury that they were required to determine whether
    the fetus was viable as part of their determination whether the
    fetus had been murdered.    The judge explained that "[a] killing
    is not murder unless a human being has been killed.     A viable
    fetus is a human being under the law of homicide.     A fetus is
    viable when there is a reasonable likelihood of the fetus's
    sustained survival outside the womb, with or without artificial
    support."
    The defendant recognizes that this instruction "apparently
    has the imprimatur of this [c]ourt."     He argues, however, that
    the instruction that this court accepted in Crawford is
    constitutionally flawed, because the third sentence would allow
    a jury to find that a fetus was a human being if there were
    merely a "reasonable likelihood" of sustained survival outside
    the womb.    In the defendant's view, the instruction "dilute[s]"
    the Commonwealth's burden to prove beyond a reasonable doubt
    that the fetus was viable.
    39
    Although the defendant did not object to the judge's
    instruction at trial, he argues that it resulted in structural
    error requiring reversal without a showing of actual harm.
    "[T]here is a very limited class of cases presenting structural
    errors that require automatic reversal absent waiver.    Such
    errors include the denial of counsel or the right to public
    trial, the omission of an instruction on the standard of beyond
    a reasonable doubt, racial discrimination in the selection of a
    jury, or trial before a biased judge.     These errors contain a
    defect affecting the framework within which the trial proceeds,
    rather than simply an error in the trial process itself"
    (quotations and citations omitted).     Commonwealth v. Francis,
    
    485 Mass. 86
    , 99-100 (2020), cert. denied, 
    141 S. Ct. 2762 (2021)
    .   An error in defining an element of the crime, as the
    defendant alleges in this case, is not among the very limited
    class of structural errors requiring automatic reversal.     See
    Commonwealth v. McCray, 
    93 Mass. App. Ct. 835
    , 845 (2018)
    (omission of element of crime from judge's charge did not
    constitute structural error and was subject to harmless error
    analysis).   See also Neder v. United States, 
    527 U.S. 1
    , 8
    (1999) ("jury instruction that omits an element of the
    offense . . . differs markedly from the constitutional
    violations we have found to defy harmless-error review").       We
    therefore review the defendant's argument for a substantial
    40
    likelihood of a miscarriage of justice.   See Wright, 
    411 Mass. at 681
    .
    Because Galperina was approximately one week away from her
    delivery date, and the fetus was full term, there was no
    substantial likelihood of a miscarriage of justice in the
    purported diminution of the Commonwealth's burden to prove that
    the fetus was viable.5   Given the facts of this case, and as the
    language used in Crawford is no longer included in the Model
    Jury Instructions on Homicide, there is no need to consider the
    question whether the "reasonable likelihood" portion of the
    Crawford instruction on viability relates to a preliminary
    question of fact that need not be proved beyond a reasonable
    doubt.
    g.   Discharge of deliberating juror.   On the second full
    day of deliberations, the judge received a note from the
    foreperson reading, "We are concerned that one juror is not able
    5 The defendant also contends that the judge, sua sponte,
    should have provided the jury with an involuntary manslaughter
    instruction, and that the failure to do so created a substantial
    likelihood of a miscarriage of justice. The instruction, he
    argues, was based on the "entirely plausible -- indeed likely --
    [proposition] that [he] was not even thinking of the fetus when
    he stabbed Galperina." We conclude that the judge was not
    required to instruct on this lesser included offense where no
    rational view of the evidence established that the defendant
    "was not even thinking about the fetus." This theory would have
    been farfetched given the defendant's position at trial that he
    "lost it" in light of evidence introduced at trial centered
    around Galperina's pregnancy and the defendant's expected
    relationship with his unborn son named "David."
    41
    to productively contribute to deliberations."   The judge
    questioned the foreperson with the caveat that the foreperson
    not reveal "anything about [the jury's] deliberations."     The
    foreperson reported that juror no. 12 "[s]everal times . . .
    refused to participate" in deliberations and seemed mentally
    unstable.   The foreperson also stated that this was "not related
    to the case."
    Where reliable information comes to a judge suggesting a
    lack of impartiality, bias, extraneous influence, or inability
    to deliberate on the part of one of the jurors, a judge should
    conduct a voir dire of the juror.   See, e.g., Commonwealth v.
    Robinson, 
    482 Mass. 741
    , 748 (2019) (possible extraneous
    influence and prejudice); Commonwealth v. Colon, 
    482 Mass. 162
    ,
    182-183 (2019) (question of lack of impartiality due to racial
    or ethnic bias); Commonwealth v. Villalobos, 
    478 Mass. 1007
    ,
    1007-1009 (2017) (possibly inattentive or sleeping juror);
    Commonwealth v. McGhee, 
    470 Mass. 638
    , 643-646 (2015) (same).
    Here, the judge determined, based on the note, that he had
    enough information to inquire of juror no. 12 due to her alleged
    refusal to deliberate.   The judge began the voir dire by
    informing the juror, "[W]hen you answer the questions, as
    difficult as it is, I can't have you tell me anything about the
    content about the deliberation . . . .   In other words, don't
    talk to me about anything that you have talked about with your
    42
    fellow jurors during jury deliberations."    The juror responded,
    "I understand what the constraint is."    She explained that it
    had been a "difficult day" and that there were "a lot of
    emotions around," but that she had been able to participate in
    the discussions.   The judge invited both sides to suggest
    further questions, and they each indicated that they were
    satisfied with the inquiry.   The judge ruled that, at that
    point, he did not have adequate grounds to discharge the
    deliberating juror.   Defense counsel then noted that he was
    concerned that juror no. 12 "basically grabbed a point of view
    and [was] sticking to it" and had "not mentally even explored
    her position or anyone else's."    Counsel added that the
    defendant was "content to have her removed."
    The judge decided to ask juror no. 12 additional questions
    about her ability to deliberate.   She answered that she could
    participate fully in deliberations.   She indicated that she felt
    "singled out" because she had "a difference of opinion in
    weighing of evidence."   Based on his observations of the juror,
    the judge made clear that the juror's angry and unstable
    demeanor would not be apparent from the trial transcripts.
    Defense counsel agreed; he commented that juror no. 12 was
    "immediately strident" and "angry" and appeared to be incapable
    of following the judge's instruction to keep an open mind.
    43
    Counsel also asserted that the voir dire hearings had made juror
    no. 12 "more damaged."
    The judge indicated that he would consider an agreement to
    discharge the juror.     He added, "If there was an objection from
    either party, . . . I probably wouldn't excuse [juror no. 12]."
    Defense counsel stated that juror no. 12 should be discharged
    and that he would object if the juror were to remain on the
    jury.   The judge then conducted a colloquy with the defendant.
    The defendant said that he had had an adequate opportunity to
    consult with counsel on the issue, and that he was acting on the
    advice of counsel and agreed to defer to counsel's judgment.
    The judge discharged juror no. 12.
    The defendant now argues that it was error to discharge the
    deliberating juror without following the requirements set forth
    in Commonwealth v. Connor, 
    392 Mass. 838
    , 843-846 (1984).      In
    particular, the defendant points out, the juror was not informed
    that she could not be discharged unless she had a personal
    problem unrelated to her relationship with other jurors or their
    views of the case.   The defendant maintains that this error
    created a substantial likelihood of a miscarriage of justice.
    "The discharge of a deliberating juror is a sensitive
    undertaking and is fraught with potential for error.    It is to
    be done only in special circumstances, and with special
    precautions.   Great care must be taken to ensure that a lone
    44
    dissenting juror is not permitted to evade his
    responsibilities."     Connor, 392 Mass. at 843.   A judge is
    required to hold a hearing "to determine whether there is good
    cause to discharge a juror."    Id. at 844.   "At the hearing, the
    issues of the case and the juror's relationship to his [or her]
    fellow jurors are not to be discussed. . . .       If the 'problem'
    juror is questioned, the judge should preliminarily inform [the
    juror] that [the juror] cannot be discharged unless [the juror]
    has a personal problem, unrelated to his [or her] relationship
    to his [or her] fellow jurors or his [or her] views on the
    case."   Id. at 845.
    We agree with the defendant's argument that the judge
    failed strictly to adhere to our holding in Connor, 
    392 Mass. at 843-846
    .   The judge took "utmost caution . . . to avoid invading
    the province of the jury," see 
    id. at 844
    , by instructing juror
    no. 12 not to discuss the content of the jury's deliberations.
    He did not, however, preliminarily notify juror no. 12 that she
    could not "be discharged unless [she] has a personal problem,
    unrelated to [her] relationship to [other] jurors or [her] views
    on the case."   
    Id. at 845
    .   See Commonwealth v. Williams, 
    486 Mass. 646
    , 656 (2021).
    Having determined that the judge did not provide juror
    no. 12 an adequate preliminary warning, we consider whether this
    error created a substantial likelihood of a miscarriage of
    45
    justice.    "General Laws c. 234A, § 74, provides that any
    'irregularity' with respect to discharging or managing jurors
    will not lead to vacatur unless the error is preserved by
    objection and the 'objecting party has been specially injured or
    prejudiced thereby.'"     Williams, 486 Mass. at 657.   See
    Swafford, 
    441 Mass. at 336
     ("While we have established
    guidelines that trial judges must follow when discharging a
    deliberating juror," verdict is not set aside unless objecting
    party is prejudiced); Commonwealth v. Garrey, 
    436 Mass. 422
    , 431
    (2002) (verdict shall not be set aside based on irregularity in
    discharging deliberating juror absent objection and prejudice).
    Here, defense counsel requested the discharge of juror
    no. 12 and objected to her remaining on the jury.       The defendant
    has not pointed to any prejudice, however, from the assented-to
    discharge of juror no. 12 beyond speculation that "she was a
    dissenting or hold-out juror, leaning towards a manslaughter
    verdict."    See Commonwealth v. Tiscione, 
    482 Mass. 485
    , 493
    (2019) (discharge of juror had impact on case where jury
    appeared deadlocked).     We therefore conclude that there was no
    substantial likelihood of a miscarriage of justice.
    h.      Relief pursuant to G. L. c. 278, § 33E.   We have
    carefully reviewed the entire record, pursuant to our duty under
    G. L. c. 278, § 33E, and discern no reason to order a new trial
    or to reduce the degree of guilt.
    46
    Judgments affirmed.
    CYPHER, J. (concurring).   I concur with the court's opinion
    completely.   I write separately to call attention to the fact
    that women in the United States are more likely to be killed by
    homicide during pregnancy or soon after childbirth than to die
    from the three leading obstetric causes of maternal mortality
    (hypertensive disorders, hemorrhage, or sepsis).    Lawn & Koenen,
    Homicide Is a Leading Cause of Death for Pregnant Women in US,
    BMJ 2022;379:o2499 (Oct. 19, 2022).   "Homicide during pregnancy
    or within [forty-two] days of the end of pregnancy exceeded all
    the leading causes of maternal mortality by more than twofold."
    Wallace, Gillispie-Bell, Cruz, Davis, & Vilda, Homicide During
    Pregnancy and the Postpartum Period in the United States, 2018-
    2019, Obstetrics & Gynecology, vol. 138, no. 5, Nov. 1, 2021, at
    762-769, https://www.ncbi.nlm.nih.gov/pmc/
    articles/PMC9134264 [https://perma.cc/D7Q4-YZV2].
    It is important to emphasize that the brutal facts of this
    case are not an anomaly.   The disconcerting frequency of lethal
    violence against pregnant women warrants concomitant response
    from our justice system.   This court's acknowledgement that oral
    revelations, on their own, cannot induce a reasonable person to
    kill their pregnant partner is a laudable first step.   See ante
    at   .   I would take it one step further and reject the
    principle that discovery of infidelity, whether oral or through
    personal observation, can amount to adequate provocation to kill
    2
    a partner, standing alone.   Compare Commonwealth v. Steeves, 
    490 Mass. 270
    , 292 n.12 (2022) (expressing "serious doubt about the
    ongoing viability of [the] legal principle [that sudden
    revelation of infidelity may be adequate provocation]"),
    Commonwealth v. Paige, 
    488 Mass. 677
    , 686-687 (2021) (Cypher,
    J., concurring) (allowing discovery of infidelity as adequate
    provocation "implies that the victim, by committing adultery, is
    partly to blame for the defendant's violence . . . .   Where the
    law treats homicide as a reasonable reaction to infidelity, it
    condones femicide"), and Commonwealth v. Richards, 
    485 Mass. 896
    , 922-923 (2020) (Cypher, J., concurring) ("it is time to
    retire the legal principle that spousal infidelity, even if it
    is a sudden discovery, entitles a defendant to an instruction on
    reasonable provocation for murder"), with Commonwealth v.
    LeClair, 
    429 Mass. 313
    , 317 (1999) ("A sudden oral revelation of
    infidelity may be sufficient provocation to reduce murder to
    manslaughter").