Commonwealth v. Duguay ( 2023 )


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    SJC-13312
    COMMONWEALTH   vs.   TIMOTHY DUGUAY.
    Plymouth.    April 3, 2023. - July 28, 2023.
    Present:    Budd, C.J., Lowy, Cypher, Kafker, Wendlandt,
    & Georges, JJ.
    Homicide. Deoxyribonucleic Acid. Evidence, Scientific test.
    Practice, Criminal, Postconviction relief, New trial,
    Discovery.
    Indictment found and returned in the Superior Court
    Department on November 7, 1995.
    Following review by this court, 
    430 Mass. 397
     (1999), a
    motion for a new trial, filed on September 22, 2020, was heard
    by William F. Sullivan, J., and a motion for postconviction
    discovery, filed on February 25, 2021, was considered by him.
    A request for leave to appeal was allowed by Lowy, J., in
    the Supreme Judicial Court for the county of Suffolk.
    Michael A. Nam-Krane for the defendant.
    Arne Hantson, Assistant District Attorney, for the
    Commonwealth.
    Lisa M. Kavanaugh, Committee for Public Counsel Services,
    Michael A. Albert, Emma L. Frank, Anne Weeks, Stephanie Roberts
    Hartung, & Claudia Leis Bolgen, for New England Innocence
    Project & others, amici curiae, submitted a brief.
    2
    CYPHER, J.   Following a jury trial, the defendant, Timothy
    Duguay, was convicted of murder in the first degree on the
    theory of extreme atrocity or cruelty.   This court affirmed the
    defendant's conviction on direct appeal.    Commonwealth v.
    Duguay, 
    430 Mass. 397
     (1999).   Years later, the defendant filed
    a motion for postconviction forensic and deoxyribonucleic acid
    (DNA) analysis pursuant to G. L. c. 278A, § 2, which was
    allowed.   Following the postconviction forensic analysis, the
    defendant filed a motion for a new trial.   The motion was denied
    after a nonevidentiary hearing.1
    The defendant filed with this court a timely notice of
    appeal and a petition, pursuant to G. L. c. 278, § 33E, for
    leave to appeal from the denial of the motion for a new trial.
    A single justice granted the defendant's petition.2   On appeal,
    the defendant argues that the new forensic analysis demonstrates
    that the Commonwealth's blood and DNA trial evidence was
    unreliable and that a confluence of factors demonstrates that
    justice was not done in this case, thus requiring a new trial.
    1 The defendant also filed a motion for postconviction
    discovery. The motion judge did not rule on the motion; thus,
    it implicitly was denied. See Commonwealth v. Dubois, 
    451 Mass. 20
    , 29 (2008), citing Commonwealth v. Rosado, 
    450 Mass. 657
    , 659
    (2008) ("The failure of a judge to rule on a motion is treated
    as an implicit denial").
    2 The single justice also allowed the defendant leave to
    appeal from the denial of his motion for postconviction
    discovery.
    3
    For the reasons set forth infra, we affirm the denial of the
    defendant's motion for a new trial.3
    Background.   The facts surrounding the murder are set forth
    in detail in Duguay, 
    430 Mass. at 398-400
    .     "We summarize those
    facts here and supplement them with other relevant facts from
    the trial record and the facts found by the motion judge to be
    significant with respect to the defendant's motion for a new
    trial, all of which are supported by the record."     Commonwealth
    v. Sullivan, 
    469 Mass. 340
    , 341 (2014).
    The victim, Robert Madera, lived with his mother in
    Wareham.   The defendant lived a short walking distance away.
    When the defendant was seventeen years old and the victim was
    twelve years old, they became involved in an on-and-off intimate
    relationship, which would continue for the next five years until
    the victim's death at the age of seventeen.4    Duguay, 
    430 Mass. at 398
    .
    The defendant and victim's relationship included many
    disagreements and growing animosity prior to the victim's death.
    When the victim was twelve, the defendant "constantly came
    3 We acknowledge the amicus brief submitted by the New
    England Innocence Project, Committee for Public Counsel
    Services, and Massachusetts Association of Criminal Defense
    Lawyers.
    4 The defendant was twenty-three years old at the time of
    the murder. Commonwealth v. Duguay, 
    430 Mass. 397
    , 398 (1999).
    4
    around looking for [him], asking where he was and what he was
    doing."   The victim would sneak out of his own home to go to the
    defendant's home, and during this time, the defendant told the
    victim's stepfather that he and the victim were in a sexual
    relationship and that he loved the victim.
    When the victim was about fourteen, the victim's mother
    asked the defendant to stay away from her son.   The defendant
    became angry, telephoned the victim's mother's house, called her
    uncomplimentary names, and told her to mind her own business.
    These harassing telephone calls, in which the defendant used
    vulgar language toward the victim's mother, continued for some
    time.   The victim's mother would change her telephone number,
    but the defendant always found a way to obtain her new telephone
    number.
    The defendant's harassment of those close to the victim
    went beyond the victim's immediate family.   When the victim was
    in tenth grade, the defendant told the victim's then girlfriend
    that he loved the victim.   The defendant repeatedly would ask
    the victim's girlfriend to persuade the victim to perform oral
    sex on him.   After the victim revealed to his girlfriend that
    the defendant had performed oral sex on him, the defendant began
    to telephone her house and harass her, bragging that he had had
    sex with the victim.
    5
    During the summer of 1995, the defendant talked often to
    his girlfriend about the victim.       He told her that the victim
    played games, lied, and "fucked with his mind."       The defendant
    told his girlfriend that he was going to blackmail the victim by
    threatening to tell those close to the victim about their
    intimate relationship.      The defendant also said that if the
    victim threatened to tell anyone that the defendant had molested
    him, the defendant would just say "that [the victim] had enjoyed
    it."       The defendant also telephoned his girlfriend's cousin
    during this time and told her that he was arguing with the
    victim and that he would like to kill him.      That summer, when
    the victim and his girlfriend drove by the defendant, the
    defendant called her a "bitch" and yelled at her that he was
    "going to fuck her up."
    In the weeks before the victim's death, he acted fearful
    and nervous, slept in his clothes, and kept the lights on at
    night.       The victim believed that police were watching him before
    his upcoming Juvenile Court date.5      During this time, the
    victim's uncle, Robert Gomes, had moved from Rhode Island to the
    victim's family home.       The victim believed that his uncle was
    staying with them because "people" were after his uncle, who had
    been forced to leave Rhode Island.      The victim told his then
    The victim told a prior girlfriend that he had "committed
    5
    a breaking and entering a long time ago."
    6
    girlfriend that someone was going to kill him and that he was
    afraid of "getting caught in the middle" of the uncle's alleged
    dispute.   The victim's uncle did not leave Rhode Island,
    however, because someone was after him, and he had not told the
    victim so.   Instead, the victim's uncle had left Rhode Island to
    seek help for his substance disorder.       Nonetheless, the victim
    continued to be fidgety and nervous.
    The growing animosity between the defendant and the victim
    continued in the days leading up to the victim's death.       See
    Duguay, 
    430 Mass. at 398
    .      "Four days before the victim's death,
    the defendant received a judgment against the victim."       
    Id.
        The
    judgment stemmed from money the victim had borrowed from the
    defendant.   See 
    id.
         The victim offered to repay the defendant.
    However, the defendant stated that he would rather have the
    victim spend the night with him than be repaid the money owed
    under the judgment.      
    Id.
       "That evening, . . . a Thursday, the
    defendant and the victim spent the night together and were
    intimate."   
    Id.
         The defendant and victim had planned to spend
    Sunday night together, the night before the murder, but the
    victim had gone out with a female friend and spent the night at
    his own home.      See 
    id.
    On the day of the murder, the victim was agitated and
    wanted to visit his mother at her place of work, telling her
    that he needed to talk to her.      The victim had spent some time
    7
    that day with his girlfriend and told her "that if he told her
    what was going on, she would not love him and would leave him."
    The victim indicated that something happened when he was twelve
    years old and that he had been warned never to tell anyone.
    That same day, after the victim did not spend Sunday night
    at the defendant's home, the defendant telephoned the victim and
    demanded to know where the victim had been the night before.
    Duguay, 
    430 Mass. at 398
    .   The victim's mother's cousin, who
    lived next door, was listening to a police scanner on the
    evening of the murder and heard the defendant loudly and angrily
    accuse the victim of standing him up.   The cousin also heard the
    defendant tell the victim that he was coming over to tell the
    victim's mother "everything" and was going to "fuck up" the
    victim.   The defendant drove to the victim's house twice on the
    day of the murder, but each time, the victim refused to talk to
    the defendant and told him to leave.6   
    Id. at 398-399
    .
    Approximately one to two hours before the murder, the
    defendant told a friend that the victim was supposed to spend
    the night with him but did not.   Duguay, 
    430 Mass. at 399
    .     He
    told her that he was tired of being hurt by the victim and said
    6 After the defendant had driven to the victim's home to
    speak with the victim, and the victim told the defendant to
    "leave [him] alone," the victim told his uncle, Joseph
    Vasconcelos, "Timmy Duguay is a pain in the ass. He just keeps
    bugging me, he won't leave me alone."
    8
    that he was going to kill the victim.   Approximately twenty
    minutes before the murder, the defendant telephoned the victim's
    home and left a voice message for the victim's mother.      
    Id.
       In
    the message, the defendant told the victim's mother that he had
    been having a sexual relationship with the victim, that the
    victim was "going to answer for the head games he's played with
    [the defendant]," and that the victim was not going to threaten
    the defendant "because [the defendant was] just going to turn
    [him]self in and [he has] already started that."   
    Id.
       The
    defendant also warned the victim's mother that she ought to "get
    ready for a fun ride at the courthouse."   
    Id.
    Around 7:15 P.M. on the night of the murder, a friend of
    the victim telephoned him, but the victim said he could not talk
    because "someone was coming," and the victim hung up.    When the
    friend telephoned again, the victim sounded scared, said that
    someone was coming, and then said that someone was there with
    him at the house.   The victim told her "to never call back and
    hung up."   When the friend drove to the victim's home at
    approximately 7:40 P.M., she knocked on the front door and
    honked her car horn but received no response.
    At approximately 7:50 P.M., the victim's aunt, who lived in
    a neighboring house, was walking her dog and saw the victim walk
    out the front door of the home and fall to the ground face down.
    The victim's face was smeared with blood, and the aunt rushed
    9
    into the home to call for an ambulance.       As the ambulance was
    driven onto the victim's street, the driver saw someone in dark
    clothes walking in the opposite direction from the victim's
    home.    Duguay, 
    430 Mass. at 399
    .    Although there were loud
    screams coming from the direction of the victim's home, the
    dark-clothed person did not turn around or react in any way and
    continued to walk away.     See 
    id.
    The victim could not speak, was struggling to breathe, and
    had multiple stab wounds to his neck, face, and chest.        Duguay,
    
    430 Mass. at 399
    .    He died in the ambulance en route to a
    hospital.   Police were dispatched to the crime scene and learned
    that the defendant's vehicle was seen being driven from the
    victim's house earlier that evening.7       
    Id.
       This prompted police
    to go to the defendant's house.8      
    Id.
    When police arrived at the defendant's house, he told them,
    "I knew you were coming."    The defendant was then read his
    Miranda warnings and agreed to go to a police station to talk.
    While in the back seat of the police cruiser, the defendant
    asked what police wanted to know.      When an officer responded
    that the defendant should just tell them what happened, the
    7 An officer collected as evidence a steak knife on the
    staircase by the sliding door. The knife did not appear to have
    blood on it.
    8 Police ultimately looked at other suspects after speaking
    to the victim's uncle, Robert Gomes.
    10
    defendant replied, "If I tell you what happened you'll put me
    away for the rest of my life."
    On arriving at the police station, the defendant was read
    the Miranda warnings again and was interviewed.     Duguay, 
    430 Mass. at 400
    .   The defendant was sweating and appeared nervous.
    He initially denied his sexual relationship with the victim, but
    after police told the defendant that they knew of the voice
    message that he left for the victim's mother, he admitted to his
    relationship with the victim.    
    Id.
       The defendant told police
    that he was tired of the victim playing "head games," as the
    victim had threatened to send the defendant to jail for life for
    raping him when the victim was twelve.
    The defendant also admitted that he had lent money to the
    victim and obtained a judgment against him.    He also told police
    that the victim recently had "started hanging around with a bad
    crowd," and that he had telephoned police to report the victim
    and his friends for illegal activities.    The defendant admitted
    that he had argued with the victim in the days before the murder
    and thought that the victim's family might have telephoned
    police because of their argument.
    During the interview, the defendant was wearing the same
    dark clothes as he had been wearing since the middle of the day.
    Duguay, 
    430 Mass. at 400
    .   An officer observed the defendant's
    hands and arms and did not observe any blood or recent wounds.
    11
    With the defendant's consent, the defendant was fingerprinted
    and had his clothes tested for blood by a State police chemist,
    Lori Bunnell.
    Bunnell performed an ortho-tolidine screening test for the
    presence of blood on the defendant's hands.    Bunnell testified
    that any type of blood, including human, animal, and insect
    blood, and blood from meat, would cause a positive reaction.
    Human blood causes an immediate bright blue reaction, while
    slower reactions can be caused by vegetation, rust, and
    detergents.9    Other bodily fluids like saliva and feces also
    would cause a reaction.    A positive ortho-tolidine test result
    is indicative of the presence of blood, but it does not prove
    that the substance is blood.    Thus, the ortho-tolidine testing
    is presumptive testing only for blood.
    There was no visible blood on his hands, fingernails, or
    clothes.    Bunnell's testing revealed that the defendant's left
    hand was positive between his fingers and on the palm, but not
    on the back of his hand.    The defendant's right hand tested
    positive between his fingers, on his palm, and on the back of
    his hand.    Further testing was done on the defendant's sneakers
    and socks and the soles of his feet.    The bottoms of the
    9 Bunnell did not photograph or videotape the chemical
    reaction.
    12
    defendant's sneakers and the soles of his feet tested positive,
    but his socks tested negative.
    Bunnell then conducted further ortho-tolidine testing in
    the victim's house.    The bottom of the bathroom sink and its
    handles tested positive.     Swabs of the visible blood were taken
    and were determined to be human blood.     Hair also was collected
    from a knife on the kitchen floor; however, the hair sample was
    too small for identification.
    Bunnell then conducted the same testing at the defendant's
    house.    The light switch near the entrance door tested positive.
    Red drops on the wall behind the sink tested negative.     However,
    the base of the sink, the tub faucet, the shower head, and the
    bathtub tested positive.10    The same testing was done to the
    defendant's car.    The outside and inside of the driver's side
    door, the trunk, the passenger's seat, and the car keys tested
    negative, but the steering wheel, the gear shift, the brake and
    gasoline pedals, and the driver's seat tested positive.
    After conducting testing at the defendant's and victim's
    respective homes, Bunnell returned to the police station to
    perform more testing on the defendant.     Bunnell tested the
    defendant's sneakers, turtleneck shirt, jeans, and jacket.
    10Bunnell conceded at trial that blood can fall into a sink
    when someone is shaving. The defendant's mother also recently
    had had surgery and had a leg and some toes amputated,
    unbeknownst to Bunnell.
    13
    Parts of the turtleneck shirt tested positive, as well as each
    leg of the defendant's jeans.    The interior of the pockets of
    the defendant's jeans tested negative.    The front and back of
    the defendant's jacket tested positive, but not the collar or
    the interior pockets.    The jacket had an approximately three-
    eighths inch cut on the right sleeve.
    Rectal swabs taken from the victim also were examined by
    Bunnell.    The swabs contained a relatively small amount of sperm
    cells.     The semen was type B blood, even though the defendant
    has type A blood.     Bunnell also examined hair evidence found on
    the defendant's sneakers.    The human hair was not similar to
    samples of hair of either the defendant or victim.
    A State police crime laboratory (crime lab) serologist also
    was called on to examine blood and saliva samples from the
    defendant, blood samples from the crime scene, and blood samples
    and rectal swabs from the victim.     The serologist determined
    that the blood from the crime scene was consistent with the
    victim's blood, and that none of the blood at the crime scene
    was consistent with that of the defendant.     The serologist also
    examined the rectal swabs taken from the victim and detected
    type B blood from the sample but could not opine on whether the
    type B blood came from sperm cells or mucus.11
    11The defendant has type A blood, and is a secretor, such
    that he secretes his blood type into any bodily fluids. The
    14
    After analysis of photographs and video recordings of the
    crime scene by a State police trooper trained in bloodstain
    analysis, the trooper testified that it was his opinion that the
    victim was attacked from behind on the couch, stumbled across
    the room, grabbed onto various items of furniture for support,
    stumbled toward and out of the front door, and fell onto the
    front lawn.    In closing, the Commonwealth emphasized the soured
    relationship between the defendant and the victim, and the
    incriminating statements made by the defendant to his girlfriend
    shortly before the murder, as well as to the victim's mother and
    police.    The Commonwealth also emphasized that the ortho-
    tolidine tests that came back positive were indicative of the
    presence of blood.    The Commonwealth, however, did not mention
    the unidentified hairs found on the kitchen floor or on the
    knife.
    Defense counsel emphasized the lack of physical evidence,
    i.e., fingerprints, blood, or hair, conclusively tying the
    defendant to the victim's murder.    Defense counsel emphasized
    that, although the murder scene was a "blood bath," there was no
    conclusive proof of blood on the defendant's hands, clothes, or
    car.     Defense counsel attacked the presumptive ortho-tolidine
    testing as too sensitive to too many different substances.
    victim had type B blood, but the serologist could not determine
    whether he also was a secretor.
    15
    Defense counsel also emphasized that the hair found on the knife
    at the crime scene did not match that of either the defendant or
    the victim.    Defense counsel then emphasized the victim's
    alleged fear of anonymous drug dealers who, the victim claimed,
    were after his uncle.
    The jury convicted the defendant of murder in the first
    degree on a theory of extreme cruelty or atrocity.     This court
    affirmed the conviction on direct appeal.     See Duguay, 
    430 Mass. at 398
    .   In his direct appeal, we concluded that the ortho-
    tolidine screening tests were not unfairly prejudicial without
    confirmatory testing, particularly where the defendant "freely
    and repeatedly pointed out the limitations of the test."      
    Id. at 402
    .
    In 2016, following multiple pro se motions by the
    defendant, as well as a petition for Federal habeas corpus
    review, the defendant filed a motion for postconviction DNA
    analysis pursuant to G. L. c. 278A.     The motion was allowed.
    The defendant then filed a motion for a new trial and, in
    support, presented forensic retesting of the evidence examined
    by Bunnell.
    The forensic retesting of the evidence included serology
    and short tandem repeat (STR) analysis DNA testing on the knife,
    and the defendant's jeans, jacket, turtleneck shirt, and
    sneakers.     STR testing also was conducted on the broken knife
    16
    handle, the hair from the knife, and a hair sample from the
    victim's uncle.12
    STR analysis on the left exterior pocket of the defendant's
    jeans, although inconclusive, contained a mixed profile with one
    male contributor.   The front knee areas of the jeans had on them
    DNA consistent with that of the defendant, and the victim was
    excluded as the source of that DNA profile.   The same was true
    about the back of the right knee of the defendant's jeans.    The
    testing on the exterior front right pocket, back right pocket,
    back of the left knee, and back left pocket also was
    inconclusive.
    STR analysis on the jacket resulted in a mixture of two
    profiles on the exterior front left chest; both the defendant
    and victim were excluded as contributors of those profiles.     The
    remainder of the testing on the jacket either was inconclusive
    or produced no DNA profile.   The same is true of the defendant's
    turtleneck shirt, as no conclusions could be made about a
    partial DNA profile that was discovered on the turtleneck shirt.
    Analysis of the defendant's sneakers also resulted in the
    12The defendant submitted an affidavit of a private
    forensic DNA consultant who averred that the new short tandem
    repeat (STR) analysis testing kits were more sensitive than
    methods used at the time of the victim's murder. The test used
    was the extremely sensitive PowerPlex Fusion 6C DNA test, which
    was one of the latest generations of STR tests.
    17
    detection of a partial mixed profile, but again, no conclusion
    could be drawn from it.
    Finally, a DNA profile on the knife blade and handle
    matched the victim and excluded the defendant.    The same applies
    to a DNA profile from blood spatter on the wall behind the
    couch.   DNA on a cigarette from the crime scene matched that of
    the victim and excluded the defendant, which also was the result
    of sperm fractions taken from the victim's rectum with a rectal
    swab.
    The defendant also obtained mitochondrial DNA (mtDNA)
    testing on hair samples taken from the knife at the crime scene,
    as well as from the victim's maternal uncle.     The testing
    excluded Gomes and his maternal relatives as contributors to the
    hairs on the knife, and also excluded the defendant.
    In addition to DNA analysis, phenolphthalein presumptive
    blood testing was performed on many of the areas that tested
    positive during Bunnell's ortho-tolidine testing, including the
    defendant's sneakers, turtleneck shirt, jeans, and jacket.     The
    defendant's jeans tested negative.   His jacket tested
    inconclusive yet contained a component that reacted with
    phenolphthalein.   The turtleneck shirt and sneakers tested
    negative; however, the knife and knife handle tested positive.
    The defendant also presented an affidavit from William
    Best, a certified forensic examiner who reviewed the defendant's
    18
    case file, including police and forensic reports, as well as
    trial testimony of Bunnell and the State serologist.     Best
    averred that presumptive tests like ortho-tolidine tests do not
    prove the presence of blood with certainty and may give false
    positive and negative results.13   Best raised doubts as to the
    validity of the ortho-tolidine results.   For example, based on
    Bunnell's laboratory notes, Best averred that several test
    results she reported as positive were only "weak positive"
    results and therefore should have been reported as negative
    results.14
    In response to the forensic and DNA evidence submitted by
    the defendant, the Commonwealth submitted an affidavit of its
    own expert, Diane Biagiotti, a forensic scientist in the DNA
    unit of the State police crime lab.   She averred that
    environmental factors, such as heat, humidity, and sunlight, as
    well as the passage of time, can degrade DNA samples, thus
    affecting any DNA profile obtained.   Biagiotti averred that DNA
    13The defendant submitted a 1991 article from the Journal
    of Forensic Sciences that phenolphthalein is the best
    presumptive test for blood because it is the most specific and
    does not react to plant peroxidases like the ortho-tolidine
    testing. Cox, A Study of the Sensitivity and Specificity of
    Four Presumptive Tests for Blood, 36 J. Forensic Sci. 1503,
    1503-1511 (Sept. 1991).
    14The defendant also introduced an affidavit from Tracey
    Ray, a forensic chemist and consultant, who echoed the opinion
    of Best that Bunnell should not have reported certain tests as
    positive. Ray viewed Bunnell's trial testimony as misleading.
    19
    profiles taken so many years later may not be suitable for
    comparison.     Furthermore, she also declared that STR DNA
    testing, while human specific, cannot determine from which types
    of cells or biological fluid the DNA profile originated.
    Despite the recent DNA and forensic analysis discussed
    supra, the motion judge denied the defendant's latest motion for
    a new trial.    The judge found that neither the phenolphthalein
    presumptive blood testing nor the mtDNA testing was newly
    discovered.15    While STR DNA testing was available at the time of
    trial, the specific PowerPlex Fusion 6C DNA test was not.     Thus,
    the motion judge concluded that the evidence was newly
    discovered.     Where the evidence provided only impeachment value,
    and merely was cumulative of much of the other evidence at
    trial, the motion judge concluded that the new evidence did not
    cast real doubt on the justice of the defendant's conviction.
    The defendant filed a timely notice of appeal in the
    Superior Court.     In the county court, he then filed a petition
    for leave to appeal from the denial of his motion for a new
    trial pursuant to G. L. c. 278, § 33E, which was granted by a
    single justice.
    15Although the judge found that this testing did not
    constitute newly discovered evidence, he determined that the
    evidence did not create a substantial risk of a miscarriage of
    justice. The same is true for the defendant's argument in his
    motion that there was a confluence of factors that warranted the
    order of a new trial.
    20
    Discussion.    "Rule 30 (b) of the Massachusetts Rules of
    Criminal Procedure, as appearing in 
    435 Mass. 1501
     (2001),
    authorizes a judge to 'grant a new trial at any time if it
    appears that justice may not have been done.'"    Commonwealth v.
    Watkins (No. 1), 
    486 Mass. 801
    , 803-804 (2021).     See
    Commonwealth v. Mazza, 
    484 Mass. 539
    , 551 (2020).     "A motion for
    a new trial is addressed to the sound discretion of the judge."
    Commonwealth v. Sanchez, 
    485 Mass. 491
    , 498 (2020).       Generally,
    "[a]n appellate court will examine the motion judge's conclusion
    only to determine whether there has been a significant error of
    law or other abuse of discretion."    
    Id.,
     quoting Commonwealth v.
    DiBenedetto, 
    458 Mass. 657
    , 664 (2011).   However, where the
    motion judge neither presided over the trial nor conducted an
    evidentiary hearing, we are in as good a position as the motion
    judge to assess the documentary evidence found within the
    record, thus allowing this court to review the judge's decision
    de novo.   See Mazza, supra at 547.
    Where the defendant's motion for a new trial is based on
    new evidence, the defendant must demonstrate that (1) "the
    evidence is either 'newly discovered' or 'newly available,'" and
    that (2) "it 'casts real doubt' on the justice of the
    defendant's conviction."   See Sullivan, 
    469 Mass. at 350
    .      See
    also Commonwealth v. Grace, 
    397 Mass. 303
    , 305-306 (1986).       "New
    evidence will cast real doubt on the justice of the conviction
    21
    if there is a substantial risk that the jury would have reached
    a different conclusion had the evidence been admitted at trial."
    Sullivan, 
    supra,
     citing Grace, 
    supra at 306
    .
    1.   STR DNA testing.     First, the defendant argues that the
    STR DNA testing is newly available evidence that would have
    played a role in the jury's deliberations.     More specifically,
    the defendant alleges that the DNA results obtained from the
    retesting of the defendant's clothes and sneakers and the murder
    weapons casts real doubt on the justice of the defendant's
    conviction.
    Before analyzing whether the STR DNA testing casts such
    real doubt, we must first analyze whether the evidence
    constitutes "newly discovered," or "newly available," evidence.
    See Grace, 
    397 Mass. at 306
     (defendant must demonstrate that new
    evidence was "unknown to the defendant or his counsel and not
    reasonably discoverable by them at the time of trial").        While
    the motion judge found that STR DNA testing existed at the time
    of the defendant's trial, see Commonwealth v. Rosier, 
    425 Mass. 807
    , 811-813 (1997), the particular test, i.e., the PowerPlex
    Fusion 6C DNA test, is an extremely sensitive, new generation of
    STR DNA testing that was not available in 1997.     Therefore, we
    conclude that the defendant has satisfied his initial burden,
    i.e., that the STR DNA testing constitutes newly available
    evidence.     See Sullivan, 
    469 Mass. at
    350 n.6 (particular
    22
    forensic testing methodology that had not yet been developed or
    gained acceptance by courts may constitute newly available
    evidence).
    Because the STR DNA testing constitutes newly available
    evidence, our analysis hinges on whether such evidence would
    have been a real factor in the jury's deliberations, such that
    it would have cast real doubt on the justice of the defendant's
    conviction.   See Commonwealth v. Lessieur, 
    472 Mass. 317
    , 331,
    cert. denied, 
    577 U.S. 963
     (2015), quoting Commonwealth v.
    Santiago, 
    458 Mass. 405
    , 415 (2010) ("A defendant seeking a new
    trial on the ground of newly discovered evidence must establish
    both that the evidence is newly discovered and that it casts
    real doubt on the justice of the conviction" [emphasis added]).
    The defendant argues that the STR DNA testing swabbed the
    exact same areas of the defendant's clothes and sneakers that
    Bunnell testified were positive for the presence of blood, and
    obtained partial DNA profiles from three small areas of the
    defendant's jeans and one small area of the defendant's jacket,
    which excluded the victim as a possible contributor.   Where the
    victim was excluded from the partial DNA profiles collected from
    the defendant's jeans, the defendant argues that the DNA
    evidence demonstrated that the victim's blood was absent from
    the defendant's clothes; thus, the defendant contends, this
    evidence conclusively refuted Bunnell's testimony that the
    23
    ortho-tolidine testing indicated the presence of blood on his
    clothes.    Therefore, the defendant argues that Bunnell's
    testimony and the admission of her handwritten notes were
    improper.
    The defendant's argument is somewhat misleading, however,
    because it assumes that, because the victim conclusively was
    excluded from these partial DNA profiles, it necessarily also
    must follow that the victim's DNA entirely was not present on
    the defendant's clothes.     While the STR DNA testing excludes the
    victim as a contributor to the specific partial DNA profiles
    found on the defendant's jacket and jeans, most, if not all, of
    the other DNA testing was inconclusive at best.     Much of the
    other partial DNA profiles from the defendant's clothes could
    not either include or exclude the victim as a possible
    contributor.   The same is true from the testing of the
    defendant's sneakers, because while a partial DNA profile was
    found on the sneakers, no conclusion could be drawn as to
    whether the victim was included as a contributor to the profile.
    The defendant compares the STR DNA testing to the
    additional testing done in Commonwealth v. Cowels, 
    470 Mass. 607
    (2015).    In Cowels, the Commonwealth introduced two bloodied
    towels at trial to suggest that both defendants had used the
    towels to clean themselves after stabbing and killing the
    victim.    
    Id. at 607-608
    .   Testing of the towels at that time,
    24
    however, neither identified nor excluded the defendants and the
    victim as the sources of the blood.    
    Id. at 608
    .   It was not
    until additional testing was done on one of the towels, years
    after the defendants' convictions had been affirmed, that it was
    revealed that the blood on the towel conclusively did not belong
    to either the defendants or the victim, but instead belonged to
    an unidentified male.   
    Id.
       In ordering a new trial, this court
    emphasized that there was no other forensic evidence at the
    crime scene, except the towel, that was linked to the
    defendants.   
    Id. at 619
    .   In a case with a "dearth of physical
    evidence," the towels served as the most important piece of
    evidence to corroborate the testimony of the prosecution's key
    witness, who presented significant credibility issues.     See 
    id.
    Thus, the towels likely were a real factor in the jury's
    deliberations and ultimate convictions of the defendants.     
    Id. at 623-624
    .
    Unlike in Cowels, where it conclusively was proved that
    none of the blood found on the towel belonged to either the
    defendant or the victim, the STR DNA testing of the defendant's
    clothes and sneakers does not exclude both the defendant and the
    victim as the contributor of the partial DNA profile.     See 
    id. at 620
     (new testing conclusively established that blood did not
    come from either defendants or victim).   It also does not point
    conclusively to an unidentified male, as did the additional
    25
    testing done in Cowels.   See 
    id.
        Rather, the STR DNA testing
    only conclusively excludes the victim as a contributor to a
    partial DNA profile on three small areas of the defendant's
    jeans and one small area on his jacket.
    Furthermore, in Cowels, the bloodied towel was the only
    piece of physical evidence that linked the defendants to the
    bloody stabbing.   See 
    id. at 621
    .   See also Sullivan, 
    469 Mass. at 352
     (purported blood on defendant's cuffs and hair in
    defendant's pocket were "sole pieces of evidence indicating the
    defendant had been in the presence of the victim during the
    killing").   Here, there were numerous other pieces of physical
    evidence, beyond the defendant's jacket and jeans, that tested
    positive for the presence of blood following ortho-tolidine
    testing that would still link the defendant to the murder.16
    At best, where the vast majority of the additional STR DNA
    testing rendered inconclusive results, and where only the victim
    was excluded from partial DNA profiles recovered from only four
    of the many small areas of the victim's clothes that were
    16Other pieces of evidence that tested positive for the
    presence of blood following ortho-tolidine testing, excluding
    the defendant's jeans and jacket, included the following: the
    defendant's hands, his sneakers, the soles of his feet, the
    light switch at his home, the bathroom sink, the bathtub faucet,
    the movable shower head in the bathtub, the bottom tile of the
    bathtub, the steering wheel of his car, the gear shift, the
    brake and gasoline pedals, the driver's seat, and the victim's
    bathroom sink.
    26
    retested, the additional testing would serve only to impeach
    Bunnell's testimony that the presumptive ortho-tolidine testing
    indicated the presence of blood on the defendant's clothes.      Cf.
    Cowels, 
    470 Mass. at 620
     (test that would exclude definitively
    defendants and victim as source of DNA profile, and instead
    would point to unidentified male as source of DNA, would not
    merely reduce weight that jury might give evidence, but would
    instead bar admission of such evidence).   It does not, as the
    defendant argues, serve as a bar to the admission of Bunnell's
    testimony that the ortho-tolidine testing returned positive
    results for the presence of blood on much of the defendant's
    clothes.   See 
    id.
    Moreover, the impeachment value of the additional STR DNA
    testing also likely is to be quite low because the defendant
    "freely and repeatedly pointed out the limitations of the
    [ortho-tolidine] test."   Duguay, 
    430 Mass. at 402
    .   Although the
    prosecutor did allude to the importance of Bunnell's testimony
    on the ortho-tolidine testing, this argument followed defense
    counsel's powerful cross-examination of Bunnell in which defense
    counsel had asked her, "Now, in your -- and by the way, your
    testimony regarding the ortho-toluidine test, you do not mean to
    leave with this jury that you found blood on this young man,
    [the defendant], do you?"   Bunnell replied, "No."    In multiple
    follow-up answers after continued cross-examination from defense
    27
    counsel, Bunnell confirmed that she was not testifying that the
    presence of blood was found on the defendant.
    These pieces of physical evidence, i.e., the defendant's
    jacket and jeans, were not the linchpin in the Commonwealth's
    case.     Cf. Commonwealth v. Cameron, 
    473 Mass. 100
    , 110 (2015)
    (DNA evidence from complainant's underwear tipped scale against
    defendant at trial, and newly discovered evidence eliminated
    defendant as source of semen on complainant's underwear, thus
    negating key piece of physical evidence that was real factor in
    corroborating complainant's testimony).     The strength of the
    Commonwealth's case primarily was built on the other largely
    circumstantial evidence of the defendant's guilt, which included
    the defendant's hostility toward the victim following the
    turmoil in their intimate relationship, the defendant's threat
    to the victim to come over and "fuck him up," the defendant's
    statement to a third party prior to the murder that he wanted to
    kill the victim, the defendant's proximity to the victim's house
    and opportunity to commit the crime, statements to police that
    demonstrated a consciousness of guilt,17 and threatening
    telephone calls to the victim's mother in which the defendant
    17After the defendant received the Miranda warnings, an
    officer asked the defendant to tell the officers what had
    happened. The defendant replied, "If I tell you what happened
    you'll put me away for the rest of my life."
    28
    told her to "get ready for a fun ride at the courthouse."18
    Duguay, 
    430 Mass. at 399
    .
    Ultimately, "[t]he weight and credibility of the evidence
    is the province of the jury."   Commonwealth v. Dubois, 
    451 Mass. 20
    , 28 (2008).   "Newly discovered evidence that tends merely to
    impeach the credibility of a witness will not ordinarily be the
    basis of a new trial."   Commonwealth v. Sleeper, 
    435 Mass. 581
    ,
    607 (2002), quoting Commonwealth v. Lo, 
    428 Mass. 45
    , 53 (1998).
    Where much of the STR DNA testing rendered inconclusive results,
    and where the additional testing that excluded the victim as the
    contributor to a small number of partial DNA profiles would have
    been admissible only to impeach the already powerfully impeached
    testimony from Bunnell, we conclude that the newly available
    evidence likely would not have been a real factor in the jury's
    18The defendant also argues that additional STR DNA testing
    on the murder weapons, i.e., the knife and the broken knife
    handle that were found, casts real doubt on the justice of the
    defendant's conviction. STR DNA testing revealed three partial
    profiles on the weapons, which statistically included the victim
    as the source and statistically excluded the defendant as the
    source. Contrary to the defendant's argument, this additional
    evidence only would have served for impeachment value, similar
    to the STR DNA testing performed on the defendant's clothes that
    was discussed supra. See Commonwealth v. Upton, 
    484 Mass. 155
    ,
    168 (2020) (additional newly available impeachment evidence
    generally does not warrant new trial). Therefore, the
    additional testing does not cast real doubt on the justice of
    the defendant's conviction, particularly in light of the
    strength of the other evidence strongly supporting the
    defendant's guilt. See 
    id.
    29
    deliberations and does not cast real doubt on the justice of the
    defendant's conviction.    Sullivan, 
    469 Mass. at 350-351
    .
    2.   Seminal fluid residue.    The defendant argues that the
    testing of two swabs of the victim's rectum, which revealed two
    partial DNA profiles that were consistent with the victim,
    demonstrates that the defendant was not the contributor of the
    semen evidence.    The defendant claims that the newly available
    DNA evidence that excludes him as a possible donor of the
    seminal fluid residue would have been a real factor in the
    jury's deliberations and thus warrants a new trial.    We
    disagree.
    Even assuming that the DNA testing on the two swabs from
    the victim's rectum constitutes newly available evidence, the
    evidence does not cast real doubt on the justice of the
    conviction.    At trial, the Commonwealth's serologist declined to
    exclude conclusively the defendant as the donor of the seminal
    fluid residue.    She instead testified that she could form no
    conclusion as to the source of the sperm.    While the DNA testing
    certainly would impeach this testimony from the Commonwealth's
    serologist, evidence that tends only to impeach the
    Commonwealth's witness generally is insufficient to warrant a
    new trial.    See Sleeper, 
    435 Mass. at 607
     (newly discovered
    evidence that tends only to impeach credibility of witness not
    ordinarily grounds for new trial).    See also Commonwealth v.
    30
    Mitchell, 
    62 Mass. App. Ct. 769
    , 776 (2005) (same).
    Furthermore, although the serologist declined to exclude the
    defendant as a contributor, her testimony already was impeached
    powerfully when she acknowledged both that the seminal fluid
    residue was type B blood and that the defendant had type A
    blood.
    The additional DNA evidence also merely would have been
    cumulative of the other evidence presented at trial, which
    overwhelmingly demonstrated that the defendant and victim were
    in an intimate relationship.   Compare Commonwealth v. Eagles,
    
    491 Mass. 210
    , 222 (2023) (hair evidence cumulatively pointed to
    strong, overwhelming showing that defendant was in fact
    perpetrator), with Sullivan, 
    469 Mass. at 352
     (blood on
    defendant's cuffs and hair in defendant's pockets were different
    in kind and not merely cumulative of other evidence at trial).
    To the extent that the defendant argues that the seminal fluid
    was a key factor for the Commonwealth's theory of the
    defendant's motive,19 i.e., that he was a "jilted lover," there
    was extensive evidence presented at trial that the defendant and
    victim were in an on-and-off intimate relationship before the
    victim's death, irrespective of the evidence of the seminal
    fluid residue.   Such evidence included that (1) the defendant
    19Contrary to the defendant's argument, the Commonwealth
    did not address the semen evidence in its closing argument.
    31
    told the victim's stepfather that he and the victim were in a
    sexual relationship; (2) the defendant told the victim's prior
    girlfriend that he loved the victim; (3) the defendant harassed
    the victim's previous girlfriend to persuade the victim to
    perform oral sex on him; (4) after the victim revealed to his
    girlfriend that the defendant had performed oral sex on him, the
    defendant began to call her house to harass her, bragging that
    he had had sex with the victim; (5) after the defendant obtained
    a judgment against the victim in the days leading up to the
    murder, they were intimate because the defendant told the victim
    that he would rather have relations with the victim than be paid
    the money owed under the judgment; and (6) the defendant
    himself, in perhaps the most impactful evidence of the intimate
    relationship, admitted to his sexual relationship with the
    victim both in a telephone call to the victim's mother
    approximately twenty minutes before the murder and to the police
    during questioning.   Duguay, 
    430 Mass. at 399-400
    .   Therefore,
    we conclude that the evidence of the seminal fluid residue does
    not cast real doubt on the justice of the defendant's
    conviction.   Sullivan, 
    469 Mass. at 350-351
    .
    3.   Forensic testing of hair.   The defendant argues that
    the additional mtDNA testing revealed that the hair found on the
    murder weapon belonged to neither the defendant nor the victim.
    Such testing was done on the hair found on the murder weapon,
    32
    the hair taken from the victim's maternal uncle, and a saliva
    sample taken from the defendant.   The testing revealed that the
    defendant, Gomes, and all of their maternal relatives were
    excluded as the source of the hair on the knife.
    The victim is a maternal relative of his uncle, Gomes, and
    where Gomes's maternal relatives were excluded as the source of
    the hair, the defendant argues that the new mtDNA testing
    conclusively excludes the victim as a source of the hair
    evidence.   This new conclusive evidence would have been a real
    factor in the jury's deliberations, according to the defendant,
    and casts real doubt on the justice of the defendant's
    conviction.20
    20 The Commonwealth disagrees with the defendant's argument
    that the additional mtDNA testing conclusively excludes the hair
    as that of the victim. The motion judge did not have the
    benefit of the results of the most recent DNA tests performed,
    which the Commonwealth provided in its appendix in this appeal.
    The Commonwealth claims that the results of the most recent
    testing confirm that the hair on the murder weapon belonged to
    the victim because the partial DNA profile matched the victim.
    The defendant disagrees because Bunnell testified that the hair
    was found adhered to the blood found on the murder weapon and
    argues that it was the victim's blood that produced the match of
    the victim to the partial DNA profile that was discovered.
    Notwithstanding this factual dispute between the parties, where
    we conclude infra that the additional testing would have been at
    best cumulative of the evidence presented at trial, i.e., that
    the hair belonged to neither the defendant nor the victim, the
    evidence does not cast real doubt on the justice of the
    defendant's conviction and does not entitle the defendant to a
    new trial. See Commonwealth v. Moore, 
    489 Mass. 735
    , 749
    (2022).
    33
    The motion judge found that the defendant failed to
    demonstrate that mtDNA testing was unavailable in 1997 at the
    time of the defendant's trial.    See Commonwealth v. Baker, 
    440 Mass. 519
    , 528 (2003) (mtDNA analysis of hair available in
    1997).    Nonetheless, even if we were to assume that the
    additional mtDNA testing constitutes newly discovered evidence,
    the evidence would not have been a real factor in the jury's
    deliberations.    At trial, Bunnell testified that the hair sample
    found from the knife microscopically was compared to hair
    samples taken from the defendant and the victim.    Bunnell
    testified that the hair sample was similar to neither the
    defendant's nor the victim's hair.    The defendant thus was able
    to argue to the jury that the murder was committed by an
    unidentified third-party culprit, an argument clearly rejected
    by the jury.   See Commonwealth v. Barry, 
    481 Mass. 388
    , 400,
    cert. denied, 
    140 S. Ct. 51 (2019)
     (although exculpatory
    evidence further would call into question credibility of
    witness, jury clearly opted to convict defendant despite such
    extensive credibility issues).    Therefore, much like the semen
    evidence, where the additional forensic testing merely is
    cumulative of the evidence at trial, and where the hair evidence
    was not an important factor in the Commonwealth's case,21 we
    21Like the semen evidence, the Commonwealth did not address
    the hair evidence in its closing.
    34
    conclude that the additional mtDNA testing that purportedly and
    conclusively would exclude the victim as the source of the hair
    found on the murder weapon does not cast real doubt on the
    justice of the defendant's conviction.    See Commonwealth v.
    Teixeira, 
    486 Mass. 617
    , 641 (2021) (where defense counsel
    repeatedly cast doubt on witness's credibility and reliability,
    newly discovered evidence that is cumulative of other
    significant impeachment evidence not grounds for new trial).
    4.   Phenolphthalein testing.    The defendant argues that the
    phenolphthalein presumptive testing for the presence of blood
    constitutes newly discovered evidence that casts real doubt on
    the justice of his conviction.    Many of the items that tested
    positive for the presence of blood after Bunnell conducted
    ortho-tolidine testing were retested using a different
    presumptive test for the presence of blood, known as
    phenolphthalein testing.   This alternative testing is said to be
    a better presumptive test for blood because it is the most
    specific presumptive testing available and does not react to
    plant peroxidases, as does ortho-tolidine testing.
    Although the phenolphthalein testing is better testing than
    the ortho-tolidine testing performed by Bunnell, we disagree
    that the phenolphthalein testing constitutes newly available
    evidence, because phenolphthalein testing was available to the
    defendant at the time of trial.     See Commonwealth v.
    35
    DiBenedetto, 
    475 Mass. 429
    , 435 (2016) (phenolphthalein test
    performed in 1993).   See also Grace, 
    397 Mass. at 306
     (newly
    available evidence must be "unknown to the defendant or his
    counsel and not reasonably discoverable by them at the time of
    trial" [emphasis added]).   Nonetheless, even if we were to
    assume that the phenolphthalein testing constitutes newly
    available evidence, at best, the phenolphthalein testing,
    similar to the new STR DNA testing, would be useful only to
    impeach Bunnell's testimony.   Cf. Cowels, 
    470 Mass. at 620
     (test
    that would exclude definitively defendants and victim as source
    of DNA profile, and instead would point to unidentified male as
    source of DNA, would not merely reduce weight that jury might
    give evidence, but instead would also bar admission of such
    evidence).   The phenolphthalein testing would serve only as a
    competing presumptive testing, and similar to the STR DNA
    testing discussed supra, it would not bar the admission of
    Bunnell's testimony and handwritten notes on the ortho-tolidine
    testing that she conducted prior to trial.   Cf. id.
    Furthermore, as we discussed supra, Bunnell's testimony on
    the ortho-tolidine testing was already extensively impeached,
    and any additional impeachment evidence would be cumulative
    evidence and likely would not be a real factor in the jury's
    deliberation.   See Teixeira, 486 Mass. at 641.   See also
    Commonwealth v. Moore, 
    489 Mass. 735
    , 749 (2022) (new evidence
    36
    at best would provide alternate ground for impeachment and,
    thus, would not be real factor in jury's deliberations).      We
    conclude that the additional evidence of negative
    phenolphthalein testing does not cast real doubt on the justice
    of the defendant's conviction.      Sullivan, 
    469 Mass. at 350-351
    .
    5.     Confluence of factors.   The defendant argues that there
    exists a confluence of factors that act in concert with the
    newly available evidence to warrant the granting of a new trial
    pursuant to Mass. R. Crim. P. 30 (b).     See Commonwealth v.
    Rosario, 
    477 Mass. 69
    , 77-78 (2017).     According to the
    defendant, those factors include that (1) the original forensic
    evidence was not reliable; (2) the jury should not have heard
    the telephone calls between the defendant and the victim that
    were intercepted illegally by the victim's neighbor; (3) the
    murder possibly was committed by two people; (4) it was
    "impossible" for the defendant to be the murderer; and (5) the
    jury did not hear from the defendant's alibi witness, the
    defendant's girlfriend.
    "If a defendant fails to raise a claim that is generally
    known and available at the time of trial or direct appeal or in
    the first motion for postconviction relief, the claim is
    waived."   Rodwell v. Commonwealth, 
    432 Mass. 1016
    , 1018 (2000),
    citing Commonwealth v. Ambers, 
    397 Mass. 705
    , 707 n.2 (1986).
    Here, nothing in the record suggests that these arguments were
    37
    unavailable to the defendant at the time of trial, his direct
    appeal, and his first motion for postconviction relief; where
    the defendant either failed to raise these arguments in a timely
    fashion, or now attempts to relitigate issues that already have
    been addressed,22 the arguments are waived.    See Rodwell, 
    supra.
    See also Mains v. Commonwealth, 
    433 Mass. 30
    , 33-34 (2000).
    6.   Discovery motion.    The defendant argues that the judge
    abused his discretion in implicitly denying his motion for
    postconviction discovery.     The defendant sought telephone
    records, search warrant records, criminal history records, and
    police records that he believed supported his alibi and third-
    party culprit claims.   The discovery relates to the defendant's
    purported alibi witness, a claim that already has been waived by
    the defendant and addressed on Federal habeas corpus review.
    See Duguay v. Spencer, 
    791 F. Supp. 2d 271
    , 271-272 (D. Mass.
    2011).
    22The defendant previously raised the argument about the
    illegally intercepted telephone calls in a prior pro se motion
    for a new trial, which already was denied on grounds of waiver.
    The defendant also raised the argument concerning the alibi
    witness on Federal habeas corpus review. Duguay v. Spencer, 
    791 F. Supp. 2d 271
    , 271 (D. Mass. 2011). The failure to call the
    alibi witness manifestly was not unreasonable, however, and did
    not give rise to an ineffective assistance of counsel claim,
    because trial counsel made a strategic decision not to call the
    witness after speaking with her on numerous occasions and
    learning that her testimony would not help the defendant. 
    Id. at 271-272
    .
    38
    The defendant also believes that the discovery could
    confirm the defendant's belief that the victim and Gerome
    Bradley were codefendants in a breaking and entering case
    committed shortly before the victim's murder, thus giving
    Bradley a motive to kill the victim.    The defendant's third-
    party culprit defense is entirely speculative, however, and
    evidence of a third party's ill will or possible motive is
    insufficient to support a defense under the third-party culprit
    doctrine.23   Commonwealth v. Andrade, 
    488 Mass. 522
    , 533 (2021).
    At bottom, the defendant must make a prima facie showing that
    the materials sought reasonably are likely to lead to evidence
    that materially would have benefited his defense, and would have
    factored into the jury's deliberations.    See Commonwealth v.
    Moffat, 
    486 Mass. 193
    , 207 (2020).     Where the defendant provides
    nothing more than mere speculation as to what the requested
    discovery likely would lead, we discern no abuse of discretion
    in the motion judge's implicit denial of the defendant's
    postconviction motion for discovery.
    23The defendant also must prove that the alleged third-
    party culprit had the motive, intent, and opportunity to commit
    the crime. Commonwealth v. Silva-Santiago, 
    453 Mass. 782
    , 800
    (2009). The defendant does not do so here. See Commonwealth v.
    Andrade, 
    488 Mass. 522
    , 533 (2021) (third-party culprit evidence
    inadmissible when it is neither "rare" nor "unique" and "lack[s]
    probative value, [is] unduly prejudicial, and [is] likely to
    divert the jury's attention").
    39
    Accordingly, we affirm the denial of the defendant's motion
    for a new trial and his motion for postconviction discovery.
    So ordered.