***********************************************
    The “officially released” date that appears near the be-
ginning of each opinion is the date the opinion will be pub-
lished in the Connecticut Law Journal or the date it was
released as a slip opinion. The operative date for the be-
ginning of all time periods for filing postopinion motions
and petitions for certification is the “officially released”
date appearing in the opinion.

   All opinions are subject to modification and technical
correction prior to official publication in the Connecticut
Reports and Connecticut Appellate Reports. In the event of
discrepancies between the advance release version of an
opinion and the latest version appearing in the Connecticut
Law Journal and subsequently in the Connecticut Reports
or Connecticut Appellate Reports, the latest version is to
be considered authoritative.

   The syllabus and procedural history accompanying the
opinion as it appears in the Connecticut Law Journal and
bound volumes of official reports are copyrighted by the
Secretary of the State, State of Connecticut, and may not
be reproduced and distributed without the express written
permission of the Commission on Official Legal Publica-
tions, Judicial Branch, State of Connecticut.
***********************************************
     STATE OF CONNECTICUT v. FERNANDO V.*
                               (SC 19885)
       Robinson, C. J., and Palmer, D’Auria, Kahn and Ecker, Js.**

                                  Syllabus

Convicted of the crimes of sexual assault in the second degree and risk of
    injury to a child in connection with his alleged sexual abuse of his
    stepdaughter, B, the defendant appealed to the Appellate Court, claiming,
    inter alia, that the trial court had abused its discretion by precluding
    him from presenting the testimony of B’s longtime boyfriend, P. The
    defendant sought to introduce P’s testimony to demonstrate that B had
    not exhibited certain behavioral characteristics that were consistent
    with those commonly exhibited by victims of sexual assault, which a
    psychologist called as an expert witness testified about during the state’s
    case-in-chief. The defendant also sought to introduce P’s testimony to
    contradict testimony by B’s mother about certain behavioral changes
    that she had observed in B in the year prior to the defendant’s arrest. The
    Appellate Court concluded that the trial court had abused its discretion
    in precluding P’s testimony, as that testimony was relevant to whether B
    had exhibited behavioral characteristics typical of sexual assault victims,
    which bore directly on the central issue of whether she had been sexually
    assaulted by the defendant. The Appellate Court also determined that
    the trial court’s error was not harmless because P’s testimony could
    have helped to show that B failed to exhibit behavior often attributed
    to sexual assault victims and, therefore, could have impacted the jury’s
    verdict. Accordingly, the Appellate Court reversed the trial court’s judg-
    ment and remanded the case for a new trial, and the state, on the
    granting of certification, appealed to this court. Held:
1. This court declined to review the state’s claim, raised for the first time
    on appeal to this court, that P’s testimony about B’s behavior properly
    was excluded on the ground that it was cumulative of other evidence
    admitted at trial, as it was unpreserved, and, because the state aban-
    doned all other claims relating to the admissibility of P’s testimony and
    there were no exceptional circumstances warranting review of the state’s
    unpreserved claim, this court upheld the Appellate Court’s determination
    that the exclusion of P’s testimony was improper: the state did not claim
    in the trial court that P’s testimony should be excluded because it
    was cumulative or raise cumulativeness as an alternative ground for
    affirmance in the Appellate Court; moreover, because the issue of
    whether evidence is inadmissible on the ground that it is cumulative is
    a discretionary determination to be made by the trial court, and because
    the state never requested that the trial court rule on that issue, this
    court could not determine whether the trial court abused an exercise
    of discretion that it neither made nor was asked to make.
2. The Appellate Court correctly determined that the improper exclusion
    of P’s testimony was not harmless, as P’s testimony was necessary for
    the jury to assess B’s credibility and could have had a substantial impact
    on the verdict: the state’s case against the defendant was not strong in
    light of the absence of corroborating physical evidence and any wit-
    nesses to the alleged sexual assaults, and, because B’s testimony was
    the only evidence of the defendant’s guilt, the case largely turned on
    whether the jury believed B, and the exclusion of P’s testimony deprived
    the defense of evidence that it could have used to cast doubt on B’s
    credibility; moreover, P’s testimony was not cumulative of other testi-
    mony adduced at trial because it would have presented the jury with
    new material not heard from any other witness regarding the indicia of
    sexual abuse identified by the state’s expert witness and would have
    conflicted directly with the testimony of B’s mother that B had become
    more withdrawn in the year prior to the defendant’s arrest; furthermore,
    contrary to the state’s claims, the defendant’s opportunity to cross-
    examine B and her mother did not render the error harmless, as the
    defendant was not constrained to present his defense solely through
    witnesses selected by the state, and the behavioral template to which
   the state’s expert witness referred during his testimony was not available
   to the defendant during his cross-examination of B and her mother
   because the expert witness testified after B and her mother testified.
                 (Two justices dissenting in one opinion)
    Argued September 14, 2018—officially released March 26, 2019

                           Procedural History

  Substitute information charging the defendant with
two counts each of the crimes of sexual assault in the
second degree and risk of injury to a child, brought to
the Superior Court in the judicial district of Stamford-
Norwalk, geographical area number twenty, and tried
to the jury before Holden, J.; verdict and judgment
of guilty, from which the defendant appealed to the
Appellate Court, Keller, Prescott and Mullins, Js., which
reversed the trial court’s judgment, and the state, on
the granting of certification, appealed to this court.
Affirmed.
  Denise B. Smoker, senior assistant state’s attorney,
with whom, on the brief, were Richard J. Colangelo, Jr.,
state’s attorney, and Nadia C. Prinz, former assistant
state’s attorney, for the appellant (state).
  Mary A. Beattie, assigned counsel, for the appellee
(defendant).
                         Opinion

   ECKER, J. This is a certified criminal appeal from
an Appellate Court decision reversing a judgment of
conviction arising out of allegations by the complainant,
B, that her stepfather, the defendant Fernando V., sexu-
ally assaulted her repeatedly over a period of years
while she was in middle school and high school. The
Appellate Court reversed the judgment of conviction
on the ground that the trial court improperly precluded
the defendant from calling the complainant’s longtime
boyfriend, P, as a witness regarding his observations
of certain aspects of B’s behavior that the state’s expert
witness had testified were common symptoms of child
sexual assault. See State v. Fernando V., 170 Conn. App.
44, 68–69, 153 A.3d 701 (2016). The Appellate Court
concluded that the improper exclusion of P’s testimony
was not harmless because the evidence may have
helped ‘‘to show that B failed to exhibit behaviors often
attributed to sexual assault victims,’’ which could have
‘‘dissuaded the jury from believing B’s story generally
. . . .’’ Id., 68. We affirm the judgment of the Appel-
late Court.
                            I
   The following facts are relevant to this appeal. B
moved to Stamford from Mexico when she was nine
years old to live with her mother, brother, and the
defendant, her stepfather. The defendant adopted B in
2004, when she was ten years old, and he later petitioned
for her to obtain permanent residency in the United
States. When B initially came to Stamford, the family
lived with B’s grandmother and uncle, but eventually
her grandmother moved back to Mexico. B testified
that she was often alone with the defendant after her
grandmother’s departure, and he began to act inappro-
priately by touching her breasts. B told her mother
about the defendant’s inappropriate behavior. B’s
mother confronted the defendant, but he denied any
wrongdoing and said B was confused.
  In 2006, when B was nearing her thirteenth birthday,
the family moved to Norwalk. B testified that the defen-
dant continued to touch her inappropriately after the
move. According to B, she told her mother about the
continuing sexual misconduct, but the defendant again
denied the allegations when confronted. B testified that
the abuse escalated when the defendant forced her
to have sexual intercourse with him in the hallway
bathroom one afternoon. She testified that the defen-
dant thereafter continued to touch her inappropriately
or to force her to have sexual intercourse on a regular
basis, sometimes as often as once per week. B said that
the abuse continued until approximately 2011, when
she was sixteen or seventeen years old.
  B explained at trial that she did not disclose immedi-
ately to her mother that the defendant was forcing her
to have sex with him because she was scared of what
her mother would think. She eventually disclosed the
abuse to her mother in 2011, however, when her mother
directly asked B whether the defendant had forced her
to have sex. B and her mother then called the police,
which resulted in the present criminal case.
   The defendant was charged with one count of sexual
assault in the second degree in violation of General
Statutes § 53a-71 (a) (1), one count of sexual assault
in the second degree in violation of § 53a-71 (a) (4),
and two counts of risk of injury to a child in violation
of General Statutes § 53-21 (a) (2).1 The evidence against
the defendant consisted primarily of the testimony of
B and her mother, who testified as a constancy of accu-
sation witness and also offered evidence of B’s behav-
ior during the relevant time period. Both B and her
mother testified that B achieved good grades, partici-
pated in extracurricular activities, maintained employ-
ment without excessive absences, and continued to
enjoy reading books and pursuing musical interests.
B’s mother also testified that she did not notice any
personality changes in B when she was twelve or thir-
teen years old, but she did observe that B’s disposition
changed in the year before the defendant’s arrest. ‘‘[S]he
was more withdrawn, and I saw that she would stay in
her room,’’ ‘‘locked up,’’ explained B’s mother.
   Toward the end of its case-in-chief, after B and her
mother had testified, the state called an expert witness,
Larry M. Rosenberg, a licensed psychologist and the
clinical director of the Child Guidance Center of South-
ern Connecticut. Rosenberg testified about ‘‘delayed
disclosure,’’ which describes a commonly observed
phenomenon in sexual abuse cases that occurs when
a victim does not inform anyone of the sexual abuse
for a period of time, sometimes lengthy, despite the
suffering and trauma experienced as a result of being
abused.
    The origin of the present appeal can be traced to
the point in Rosenberg’s testimony when he was asked
by the state to opine about behavioral issues other than
delayed disclosure. More specifically, Rosenberg was
asked by the state about symptoms exhibited by vic-
tims of child sexual assault who have made a disclo-
sure. Rosenberg answered that there were a variety of
symptoms commonly observed in such victims, includ-
ing changes in behavior, disassociation, withdrawal,
depression, heightened anxiety, bad dreams, flashbacks,
sleep interruption, and changes in cognitive functioning.
Rosenberg elaborated the point on cross-examination,
explaining that depression can manifest itself in changes
in mood, irritability, and angry outbursts. He stated,
‘‘[t]he list goes on, you know, bad dreams, all sorts of
things.’’2 Rosenberg’s expert testimony apparently was
offered by the state to help the jury understand the sig-
nificance of the prior testimony of B and her mother, in
a manner consistent with the state’s objective at trial,
which was to establish the defendant’s guilt. The expert
testimony about delayed disclosure would help to
explain why B did not immediately report the most
severe abuse to her mother; the testimony about com-
mon symptoms of trauma would assist the jury in under-
standing why B had become more withdrawn prior to
the defendant’s arrest.
   After the conclusion of the state’s case-in-chief, the
defense attempted to discredit the state’s version of
events by presenting the testimony of P, B’s longtime
boyfriend. Upon hearing that B and P were in a relation-
ship, the trial court excused the jury to hear the state’s
objection that P’s testimony was not relevant to the issue
at hand. With the jury out of the courtroom, the defense
made the following offer of proof relating to the admissi-
bility of P’s testimony about B’s behavior:
   ‘‘[Defense Counsel]: When you say you’re in a relation-
ship, are you—do you consider yourself boyfriend and
girlfriend?
  ‘‘[P]: Yes.
   ‘‘[Defense Counsel]: And have you continuously gone
out with her, or been in a relationship with her, as boy-
friend and girlfriend, for four years?
  ‘‘[P]: Yes, I have.
  ‘‘[Defense Counsel]: Have there been any breaks in
the relationship?
  ‘‘[P]: No, there have not.
  ‘‘[Defense Counsel]: Now, in the time period that
you’ve been going out, as boyfriend and girlfriend, with
[B], have you noticed any significant behavioral issues
with her?
  ‘‘[P]: No, not really.
  ‘‘[Defense Counsel]: Have you noticed any pro-
nounced eating disorders?
  ‘‘[P]: No, I have not.
  ‘‘[Defense Counsel]: Have you noticed any suicidal
thoughts?
  ‘‘[P]: No, I have not.
  ‘‘[Defense Counsel]: Have you noticed any severe
depression?
  ‘‘[P]: No, I have not.
  ‘‘[Defense Counsel]: Have you noticed any eating dis-
orders?
  ‘‘[P]: No, I have not.
  ‘‘[Defense Counsel]: Have you noticed any anger or
outbursts or violence, by her?
  ‘‘[P]: No, I have not.
  ‘‘[Defense Counsel]: Have you noticed any trouble
with her focusing on issues or tasks at hand?
  ‘‘[P]: No, I have not.
  ‘‘[Defense Counsel]: And, to your knowledge, do you
know if her grades have slipped, in any way, in the four
years you’ve known her?
  ‘‘[P]: No, I don’t think so.
  ‘‘[Defense Counsel]: And, in the four years that you’ve
known her, have you noticed any type of interruption in
her playing of the flute?
  ‘‘[P]: No, I have not.
  ‘‘[Defense Counsel]: And, since September, 2011, have
you noticed any of the things that I just mentioned,
occurring with [B]?
  ‘‘[P]: No, I have not.’’
   The defense argued that P’s testimony regarding B’s
behavior was admissible because it was relevant in two
ways: first, to impeach the credibility of B’s mother, who
had testified that B had become more withdrawn, and,
second, as direct evidence regarding the occurrence or
nonoccurrence of the behavioral changes that the state’s
expert witness had testified are commonly exhibited by
child victims of sexual assault. The latter ground in par-
ticular was twice referenced by defense counsel in collo-
quy with the trial court. The state, for its part, argued
categorically that the testimony was not relevant and
pointed out that P was not qualified to offer testimony
on the subject because he was not an expert witness.
The state also argued that the evidence did not directly
impeach the testimony of B or her mother. In addition,
the state noted its concern that it could be prejudicial for
the jury to hear testimony about B’s romantic relation-
ship with P.
   The trial court ruled that P’s testimony was inadmissi-
ble in its entirety. The court stated that ‘‘[t]he relevance
of this testimony . . . is collateral, at best.’’ With
respect to impeachment, it found that ‘‘[i]mpeachment
is not, by this evidence, extrinsic evidence. It lends itself
to—it’s likely to confuse the jurors. It’s not probative
of any issues. . . . I don’t see any impeachment, based
upon what I’ve heard on this record . . . . [An] [o]ffer
of proof has been made. It’s on the record, should the
matter be reviewed. It’s there for the Appellate Court
to look at. But before the jury, it’s confusing. It’s not
probative, and . . . the objection is sustained.’’ There-
fore, P’s testimony was not presented to the jury.
  The jury returned a verdict of guilty on two counts
of sexual assault in the second degree and two counts
of risk of injury to a child. The trial court sentenced
the defendant to an effective term of ten years of incar-
ceration and ten years of special parole. The defendant
appealed from the judgment of conviction on the ground
that the trial court improperly excluded P’s testimony
from the jury’s consideration.3 State v. Fernando V.,
supra, 170 Conn. App. 46. In the Appellate Court, the
state argued that the trial court properly excluded P’s
testimony ‘‘because it was both collateral in nature and
entirely consistent with the testimony given by B and
her mother.’’ Id., 48–49. The state also contended that,
even if it was error to exclude the evidence, the error
was harmless because P’s testimony ‘‘did not differ
materially’’ from the testimony of B or her mother and
therefore the exclusion ‘‘had little effect on the jury
. . . .’’ (Internal quotation marks omitted.) Id., 69. The
Appellate Court rejected those claims, holding that P’s
testimony improperly was excluded because it was rele-
vant to ‘‘the issue of whether B had exhibited behaviors
associated with some sexual assault victims, which had
a clear and direct bearing on the central issue before
the jury, namely, whether B had been sexually assaulted
by the defendant.’’ Id., 67. The Appellate Court further
concluded that the improper exclusion of P’s testimony
was not harmless because the absence of any physical
evidence or witnesses to the sexual assaults meant that
‘‘[t]he case turned largely on whether the jury believed
B’’; id., 69; and P’s testimony, which ‘‘helped to paint B
as having been an ordinary high school girl,’’ necessarily
would have ‘‘decrease[d] the likelihood in the eyes of
the jury that an assault had occurred.’’ Id., 68. The
Appellate Court consequently reversed the judgment of
conviction and remanded for a new trial. Id., 69. This
certified appeal followed.
                            II
   The state first argues that the Appellate Court improp-
erly found that the trial court had abused its discretion
by excluding P’s testimony. The state does not rely on
the grounds it raised in the trial court or the Appellate
Court but instead contends, for the first time, that P’s
testimony regarding B’s behavior properly was
excluded by the trial court because it was cumulative
of other evidence in the record indicating that B ‘‘was
basically ‘an ordinary high school girl’ . . . dating, get-
ting good grades, participating in extracurricular activi-
ties and holding down a job.’’ (Citation omitted.) This
is a new argument. The state never argued in the trial
court that P’s testimony about B’s behavior should be
excluded because it was cumulative, nor did the trial
court base its ruling on that ground. The argument also
was not raised or briefed by the state as an alternative
ground for affirmance in the Appellate Court, and the
Appellate Court, like the trial court, did not address the
argument as part of its admissibility analysis. On this
record, we conclude that the state has failed to preserve
its belated legal theory of the inadmissibility of P’s
behavioral testimony based on cumulativeness, made
for the first time in this court, and we decline to review
the claim. Because the state has abandoned all claims
other than its contention that P’s testimony was cumula-
tive; see, e.g., Samelko v. Kingstone Ins. Co., 329 Conn.
249, 255 n.3, 184 A.3d 741 (2018) (deeming arguments
not raised and briefed in this court to be abandoned);
the decision of the Appellate Court that the exclusion
of P’s testimony was improper effectively stands
unchallenged and must be upheld.
   ‘‘This court is not bound to consider claims of law
not made at the trial. . . . In order to preserve an evi-
dentiary ruling for review, trial counsel must object
properly. . . . In objecting to evidence, counsel must
properly articulate the basis of the objection so as to
apprise the trial court of the precise nature of the objec-
tion and its real purpose, in order to form an adequate
basis for a reviewable ruling. . . . Once counsel states
the authority and ground of [the] objection, any appeal
will be limited to the ground asserted.’’ (Internal quota-
tion marks omitted.) State v. Gonzalez, 272 Conn. 515,
539, 864 A.2d 847 (2005); see also Perez-Dickson v.
Bridgeport, 304 Conn. 483, 499, 43 A.3d 69 (2012) (rule
that claim must be ‘‘raised and decided in the trial court
. . . applies equally to alternate grounds for
affirmance’’ [internal quotation marks omitted]). We
have emphasized that ‘‘[t]hese requirements are not
simply formalities. They serve to alert the trial court
to potential error while there is still time for the court
to act. . . . Assigning error to a court’s evidentiary rul-
ings on the basis of objections never raised at trial
unfairly subjects the court and the opposing party to
trial by ambush.’’ (Internal quotation marks omitted.)
Id., 540; see also State v. Miranda, 327 Conn. 451, 465,
174 A.3d 770 (2018) (‘‘[A] party cannot present a case
to the trial court on one theory and then seek appellate
relief on a different one . . . . For this court to . . .
consider [a] claim on the basis of a specific legal ground
not raised during trial would amount to trial by ambus-
cade, unfair both to the [court] and to the opposing
party.’’ [Internal quotation marks omitted.]).
   This reasoning applies with full force in the present
case, in which the state’s newly minted ground for
exclusion, based on the supposedly cumulative nature
of the excluded evidence, calls for a discretionary deter-
mination to be made by the trial court in the first
instance. See, e.g., Motzer v. Haberli, 300 Conn. 733,
742, 15 A.3d 1084 (2011) (‘‘We conclude that the trial
court did not abuse its discretion in excluding the prof-
fered evidence [as cumulative]. Our rules of evidence
vest trial courts with discretion to exclude relevant
evidence when ‘its probative value is outweighed . . .
by considerations of undue delay, waste of time or
needless presentation of cumulative evidence.’ ’’), quot-
ing Conn. Code Evid. § 4-3. This particular exercise of
discretion was not undertaken by the trial court in this
case because the state never requested a ruling on the
ground now being advanced. We cannot determine
whether the trial court abused an exercise of discretion
that it neither made nor was asked to make. Under
these circumstances, we decline to review the state’s
unpreserved claim.4
   Our rules of reviewability in the evidentiary context
are prudential in nature, not jurisdictional, but they
serve essential purposes and promote vital principles,
and only in the most compelling situation will we depart
from them. Legal claims, arguments and objections
regarding evidentiary matters ordinarily must be made
at the right time and place, because that time and place
is when the opposing party has the opportunity to
respond to the point or to cure the defect, and it also
is when the trial judge will be required to adjudicate
the disputed issue within the particularized context
defined by the circumstances then existing. Adhering
to the requirement of specificity and contemporaneity
promotes fairness between the parties and helps to
ensure that trial and appellate judges remain optimally
positioned to perform their respective roles. There are,
of course, exceptional circumstances when this court
will ‘‘consider a claim, constitutional or otherwise, that
has not been raised and decided in the trial court.’’5
Perez-Dickson v. Bridgeport, supra, 304 Conn. 499.
Nothing about the present case qualifies the state’s
unpreserved evidentiary claim for such exceptional
treatment.
   The Appellate Court determined that P’s testimony
improperly was excluded because it was relevant and
‘‘probative of the central issue of this case’’—B’s credi-
bility. State v. Fernando V., supra, 170 Conn. App. 64.
In this court, the state does not challenge the Appellate
Court’s evidentiary holding on any basis other than the
unpreserved claim of cumulativeness. Accordingly, the
determination of the Appellate Court that P’s testimony
improperly was excluded must stand.
                           III
   We now must decide whether the improper exclusion
of P’s testimony was harmless. The state makes two
arguments: first, that the excluded evidence was cumu-
lative, and, second, that the case against the defendant
was very strong and any inconsistencies in B’s testi-
mony were explored on cross-examination and consid-
ered by the jury. We disagree with both contentions.
We view the record as the Appellate Court did and
concur in its conclusion that the exclusion of P’s testi-
mony cannot be considered harmless on this record.
   The law governing harmless error for nonconstitu-
tional evidentiary claims is well settled. ‘‘When an
improper evidentiary ruling is not constitutional in
nature, the defendant bears the burden of demonstra-
ting that the error was harmful. . . . [W]hether [an
improper ruling] is harmless in a particular case
depends upon a number of factors, such as the impor-
tance of the witness’ testimony in the [defendant’s] case,
whether the testimony was cumulative, the presence
or absence of evidence corroborating or contradicting
the testimony of the witness on material points, the
extent of cross-examination otherwise permitted, and,
of course, the overall strength of the prosecution’s case.
. . . Most importantly, we must examine the impact of
the . . . evidence on the trier of fact and the result of
the trial. . . . [T]he proper standard for determining
whether an erroneous evidentiary ruling is harmless
should be whether the jury’s verdict was substantially
swayed by the error. . . . Accordingly, a nonconstitu-
tional error is harmless when an appellate court has a
fair assurance that the error did not substantially affect
the verdict.’’ (Internal quotation marks omitted.) State
v. Favoccia, 306 Conn. 770, 808–809, 51 A.3d 1002
(2012); accord State v. Jordan, 329 Conn. 272, 287–88,
186 A.3d 1 (2018); State v. Shaw, 312 Conn. 85, 102,
90 A.3d 936 (2014). We have observed that cases that
present the jury with a ‘‘credibility contest character-
ized by equivocal evidence . . . [are] far more prone
to harmful error.’’ (Internal quotation marks omitted.)
State v. Favoccia, supra, 816–17.
   The state seriously underestimates the potential
impact of the excluded testimony. As the Appellate
Court aptly pointed out, ‘‘the state’s case here was not
an exceedingly strong one’’ in light of the absence of
‘‘corroborating physical evidence or any witnesses to
the alleged sexual assaults.’’6 State v. Fernando V.,
supra, 170 Conn. App. 68–69; see also State v. Favoccia,
supra, 306 Conn. 809 (describing child sexual assault
cases that lack physical evidence and turn ‘‘entirely on
the credibility of the complainant’’ as ‘‘not particularly
strong’’ [internal quotation marks omitted]); State v.
Grenier, 257 Conn. 797, 808, 778 A.2d 159 (2001) (noting
that ‘‘the state’s case was not particularly strong’’
because child victim’s ‘‘version of the events provided
the only evidence of the defendant’s guilt’’); State v.
Alexander, 254 Conn. 290, 308, 755 A.2d 868 (2000)
(noting that ‘‘the state’s case was not particularly strong
in that it rested on the credibility of the [child] victim’’
[internal quotation marks omitted]). B’s testimony was
the only evidence of the defendant’s guilt, and, there-
fore, this ‘‘case turned largely on whether the jury
believed B.’’ State v. Fernando V., supra, 170 Conn.
App. 69. Indeed, as the state explained to the jury in
closing argument, ‘‘[w]hat this case really comes down
to is one simple question, who do you believe?’’ By
excluding P’s testimony, the trial court deprived the
defense of evidence that it could have used to cast
doubt on the credibility of B’s allegations. See State v.
Ritrovato, 280 Conn. 36, 57–58, 905 A.2d 1079 (2006)
(holding that improper exclusion of evidence pertinent
to minor victim’s credibility ‘‘would have cast sufficient
doubt on [her] credibility [so as] to have influenced the
jury’s verdict on the sexual assault charges’’).
  To understand more particularly the nature of the
potential harm caused by the exclusion of P’s testimony,
it is important to examine how that testimony became
relevant to the state’s case at trial. Evidently concerned
that a lay jury might draw unwarranted adverse infer-
ences about B’s credibility from the fact that B had
delayed telling her mother about being sexually
assaulted, the state chose to present expert testimony
at trial from Rosenberg explaining that delayed
reporting is common in child sexual abuse cases and
describing the psychological and emotional factors that
make such a delay understandable. See State v. Favoc-
cia, supra, 306 Conn. 817 (Palmer, J., dissenting)
(explaining that state may use expert testimony in child
sexual abuse cases to explain victim behavior that is
common but may not be known to laypersons). But
Rosenberg’s testimony did not stop at explaining
delayed disclosure. The state also questioned Rosen-
berg at length about postdisclosure behavioral charac-
teristics (‘‘symptoms of trauma’’) commonly observed
in teenagers and young adults who have been sexually
assaulted. Rosenberg initially responded in general
terms, stating that ‘‘being sexually abused tends to
most—most typically, but not always, reduce the level
of functioning of the person who has been victimized.’’
The state asked for greater detail: ‘‘What are some symp-
toms of trauma from child sexual assault, that you’ve
seen, in your practice, with victims who have made a
disclosure?’’ Rosenberg answered by providing exam-
ples, including ‘‘disassociation, the kind of psychic
numbing that can go on. . . . But in addition to that,
typically, symptoms would be bad dreams, flashbacks
of the events that had occurred . . . changes in func-
tioning with regard to sleep, with regard to cognitive
functioning, with regard to school functioning. [With-
drawal] is common. Depression is common. Heightened
anxiety, particularly in the face of anything that is remi-
niscent of the event. . . . And those are some of the
findings, typically.’’ During cross-examination, Rosen-
berg highlighted depression as a particularly common
symptom and explained that depression can manifest
itself in a variety of ways, including, for example,
‘‘changes in mood and irritability and angry outbursts,’’
as well as becoming ‘‘more withdrawn.’’ As he con-
cluded his answer about the most common behavioral
symptoms, Rosenberg made it clear that his description
was not exhaustive, stating that ‘‘[t]he list goes on.’’
   Rosenberg’s testimony became the lens through
which the jury reasonably could have viewed the most
critical issues in the case. The state presumably elicited
his testimony about ‘‘behavioral symptoms’’ because it
wanted to lend significance to B’s mother’s testimony
that B had become more withdrawn than usual in the
year prior to the defendant’s arrest. In fact, the state
argued this very inference in its closing argument to
the jury when it suggested that B’s withdrawal was a
sign that she had been sexually abused.7 Rosenberg’s
testimony was double-edged, however, because it pro-
vided the defense with an evidentiary basis to develop
a jury argument that B’s allegations of abuse should
not be believed. The defense sought to raise the specter
of reasonable doubt by arguing that B had not exhibited
any of the many behavioral symptoms of trauma that
the state’s own expert said were typical and common
among sexual abuse victims. Rosenberg’s testimony, in
other words, provided the defense with an opening to
argue that the absence of such symptoms equates to
an absence of abuse. The potential significance of P’s
testimony must be seen in this light.
   With this framework in place, it becomes evident
why the improper exclusion of P’s testimony was not
harmless. First, and most significantly, P’s testimony
was not cumulative because it would have presented
the jury with new material, not heard from any other
witness, regarding certain indicia of sexual abuse identi-
fied by Rosenberg. See State v. Favoccia, supra, 306
Conn. 808–809 (holding that cumulativeness is factor
to be considered in harmless error analysis). No other
witness had been asked whether B suffered from
depression, anger or outbursts of violence, or if she
had trouble focusing on issues or tasks at hand. These
particular symptoms were among those identified by
Rosenberg as common behavioral manifestations of
trauma caused by sexual abuse. The evidentiary ruling
under review excluded P’s testimony that he did not
observe B showing any of these specific symptoms of
abuse during the past four years—evidence provided
by no other witness. This testimony, if allowed, would
have supplied defense counsel with additional grounds
to argue that the abuse had never happened. New evi-
dence is not cumulative evidence.
   Second, the jury reasonably could have found that
one significant aspect of the new information contained
in P’s testimony actually conflicted with the testimony
of B’s mother and thus could not have been duplicative
of that testimony. B’s mother testified that B had
become more withdrawn prior to the defendant’s arrest,
which was made highly relevant by Rosenberg’s subse-
quent testimony that ‘‘[d]epression can manifest itself
in a variety of ways,’’ including a victim’s becoming
‘‘more withdrawn.’’ A juror reasonably could have
understood P’s testimony that B did not exhibit any
signs of depression as being inconsistent with the testi-
mony of B’s mother regarding B’s withdrawal. See
United States v. Stewart, 907 F.3d 677, 688 (2d Cir.
2018) (‘‘[T]he fact of the inconsistency gives the jury
an insight into the [witness’] state of mind; the inconsis-
tency shows that the witness is either uncertain or
untruthful. In either event, the inconsistency calls into
question the [witness’] believability.’’ [Internal quota-
tion marks omitted.]), quoting 1 K. Broun, McCormick
on Evidence (7th Ed. 2013) § 34, p. 209. The trial court’s
ruling prevented the defense from using P’s testimony
to challenge the mother’s testimony that B had become
withdrawn, which, not insignificantly, was the only
behavioral symptom of trauma allegedly exhibited by B.
The Appellate Court summarized the unfairness: ‘‘The
state cannot have it both ways: on the one hand, intro-
ducing its own evidence of B’s behavior favorable to
the state’s case and, on the other, seeking to prevent
the defendant from presenting his own contrary evi-
dence. B’s mother provided otherwise unrebutted testi-
mony that B was more withdrawn than usual and stayed
locked up in her room. The state then elicited testimony
from Rosenberg that withdrawal was common among
sexual assault victims, thereby giving damning context
to the mother’s observation. The defendant was entitled
to produce his own witness in an effort to counter
the state’s evidence and demonstrate that B had not
exhibited any behavioral characteristics that could be
associated with sexual assault victims. That witness
was P.’’ State v. Fernando V., supra, 170 Conn. App.
64–65. We believe that a reasonable juror may have
been swayed by P’s testimony when assessing whether
to believe the allegations of abuse.
   Further compounding the harm arising from the
improper exclusion of P’s testimony is the fact that the
state affirmatively used B’s mother’s testimony about
B’s ‘‘withdrawal’’ and Rosenberg’s testimony about
behavioral symptoms of trauma in its arguments to the
jury. In its closing argument, the state attempted to
focus the jury’s attention on one aspect of B’s behavior
to support B’s allegation that she had been sexually
assaulted by reminding the jury that B’s mother had
‘‘testified that even she noticed [B] was acting more
withdrawn, spending more time alone in her room.’’ In
rebuttal closing argument, the state again pointed out
that ‘‘there was testimony that showed that [B] became
more withdrawn before the arrest, that she spent more
time to herself. [B] herself testified that after the arrest,
she felt relief, that she could go home and not worry.
. . . Rosenberg testified that symptoms from a trau-
matic experience, such as child sexual assault, can
sometimes occur many years later.’’ In our view, ‘‘[s]uch
heavy reliance [on the withdrawal-related testimony]
. . . expose[s] its central role in persuading the jury
to convict, as the government clearly understood that
[the] statement was a powerful weapon in its arsenal.’’
(Internal quotation marks omitted.) United States v.
Stewart, supra, 907 F.3d 689.
   After seeking to persuade the jury to infer guilt based
on the mother’s testimony about one of the behavioral
symptoms identified by Rosenberg, the state cannot
fairly argue that it was harmless to exclude P’s conflict-
ing testimony that he saw no significant behavioral
changes or depression in B. To the contrary, the exclu-
sion of P’s testimony deprived the defense of the ability,
in its own summation to the jury, to undercut the state’s
argument by reminding the jury that P, who was among
B’s closest friends for the four years leading up to trial,
had observed none of the many symptoms of sexual
abuse that Rosenberg had identified. Cf. State v. Saw-
yer, 279 Conn. 331, 360–61, 904 A.2d 101 (2006) (finding
harm, in relevant part, because state repeatedly empha-
sized improperly admitted evidence in its closing argu-
ment), overruled in part on other grounds by State v.
DeJesus, 288 Conn. 418, 454–55 n.23, 953 A.2d 45 (2008);
State v. Alexander, supra, 254 Conn. 308 (holding that
prosecutor’s improper remarks in closing argument
were not harmless because they ‘‘directly addressed
the critical issue in this case, the credibility of the victim
and the defendant’’ [internal quotation marks omitted]).
   Lastly, the state argues, and the dissent agrees, that
the defendant’s ability to cross-examine B and her
mother renders the error harmless. This argument
ignores two important points. First, Rosenberg testified
after B and her mother, and, therefore, the behavioral
template provided by him was not available to the
defense during the cross-examination of those key wit-
nesses. More broadly, and perhaps more importantly,
a criminal defendant is not constrained to present his
defense through witnesses selected by the state. ‘‘If the
accused [is] guilty, he should [nonetheless] be con-
victed only after a fair trial’’; (internal quotation marks
omitted) State v. Andrews, 313 Conn. 266, 294, 96 A.3d
1199 (2014); which includes, among other things, an
opportunity ‘‘to present [his] version of the facts as well
as the prosecution’s to the jury so it may decide where
the truth lies.’’ Washington v. Texas, 388 U.S. 14, 19,
87 S. Ct. 1920, 18 L. Ed. 2d 1019 (1967). This does not
mean that there are no limits on the defendant’s right
to present his defense as he wishes; see State v. Wright,
320 Conn. 781, 818–19, 135 A.3d 1 (2016); but, because
P’s testimony was admissible and could have made a
substantial impact on the jury, the improper exclusion
of this testimony cannot be deemed harmless. ‘‘[T]he
truth is more likely to be arrived at by hearing the
testimony of all persons of competent understanding
who may seem to have knowledge of the facts involved
in a case, leaving the credit and weight of such testi-
mony to be determined by the jury or by the court
. . . .’’ (Internal quotation marks omitted.) Washington
v. Texas, supra, 22. Just as ‘‘the prosecution is entitled
to prove its case by evidence of its own choice,’’ so,
too, does the defendant deserve the same opportunity
to defend himself.8 Old Chief v. United States, 519 U.S.
172, 186, 117 S. Ct. 644, 136 L. Ed. 2d 574 (1997).
   It cannot be harmless error to ‘‘remove from the fact
finder the very tools by which to make a credibility
determination . . . .’’ State v. Little, 138 Conn. App.
106, 123, 50 A.3d 360, cert. denied, 307 Conn. 935, 56
A.3d 713 (2012); see also Devincentz v. State, 460 Md.
518, 562, 191 A.3d 373 (2018) (finding that complete
exclusion of witness’ testimony was not harmless error
when ‘‘[t]he outcome of [the] case turned entirely on the
relative credibility of the defendant and the accuser,’’
because the exclusion ‘‘limited the jury’s ability to
assess [the accuser’s] credibility . . . .’’). ‘‘[W]here
credibility is an issue and, thus, the jury’s assessment
of who is telling the truth is critical, an error affecting
the jury’s ability to assess a [witness’] credibility is
not harmless error.’’ Devincentz v. State, supra, 561.
Because P’s testimony was necessary for the jury to
assess B’s credibility, we conclude that the exclusion
of his testimony was not harmless.
   The judgment of the Appellate Court is affirmed.
   In this opinion PALMER and D’AURIA, Js., concurred.
   * In accordance with our policy of protecting the privacy interests of the
victims of sexual assault and the crime of risk of injury to a child, we decline
to use the defendant’s full name or to identify the complainant or others
through whom the complainant’s identity may be ascertained. See General
Statutes § 54-86e.
   ** This case originally was scheduled to be argued before a panel of this
court consisting of Chief Justice Robinson and Justices Palmer, D’Auria,
Kahn and Ecker. Although Justice Palmer was not present when the case
was argued before the court, he has read the briefs and appendices, and
listened to a recording of the oral argument prior to participating in this
decision.
   1
     Although §§ 53-21 (a) and 53a-71 (a) have been the subject of amend-
ments since 2006; see, e.g., Public Acts 2007, No. 07-143, §§ 1 and 4 (amending
§§ 53a-71 [a] and 53-21 [a], respectively); the year in which the conduct that
formed the basis of the charges in the present case began, those amendments
have no bearing on the merits of this appeal. In the interest of simplicity,
we refer to the current revision of §§ 53-21 (a) (2) and 53a-71 (a) (1) and (4).
   2
     Rosenberg testified that these various symptoms ‘‘don’t necessarily
appear in everyone and that . . . even when they do appear, [they appear]
in different kinds of ways.’’ He also said that it was ‘‘more common than
not’’ that an abuse victim between the ages of twelve and eighteen would
exhibit ‘‘some sort of behavioral difficulties,’’ and he identified depression
as among the more common of the ‘‘behavioral characteristics’’ observed
in those victims.
   3
     The defendant also raised an additional evidentiary claim in the Appellate
Court relating to the trial court’s exclusion of a different portion of P’s
testimony, which the defense had offered at trial for the purpose of
impeaching B and her mother’s earlier testimony that the ‘‘defendant had
tried to prevent the complainant from associating with boys of her own
age.’’ State v. Fernando V., supra, 170 Conn. App. 46. This particular claim
was not relied on by the Appellate Court as a basis for reversing the judgment
of conviction and is not within the scope of the question certified for review
by this court, which is limited to whether the Appellate Court improperly
determined ‘‘that the trial court [had] abused its discretion in excluding the
testimony of the victim’s boyfriend on the issue of whether she had exhibited
behaviors associated with some sexual assault victims’’ and whether the
improper exclusion of P’s testimony was harmful. State v. Fernando V., 324
Conn. 923, 155 A.3d 753 (2017). Although the defendant raised the issue
regarding his treatment of B’s male acquaintances, among other issues, as
an alternative ground on which to affirm the judgment of the Appellate Court,
we decline to address it in light of our disposition of the certified question.
   4
     The dissent suggests that this conclusion is in ‘‘apparent conflict’’ with
a line of cases holding that this court may rely on any grounds supported
by the record to affirm the judgment of a trial court, including alternative
evidentiary grounds raised for the first time on appeal. We perceive no such
conflict, however, for precisely the reason identified by the dissent when
it observes that one of the keys to resolving this issue is ‘‘whether the
alternative ground is one [on which] the trial court would have been forced
to rule in favor of the [party prevailing at trial].’’ (Emphasis added; internal
quotation marks omitted.) Footnote 2 of the dissenting opinion, quoting
State v. Cameron M., 307 Conn. 504, 526–27, 55 A.3d 272 (2012) (overruled
in part on other grounds by State v. Elson, 311 Conn. 726, 748 n.14, 91 A.3d
862 [2014]), cert. denied, 569 U.S. 1005, 133 S. Ct. 2744, 186 L. Ed. 2d 194
(2013). When a trial court that has excluded (or admitted) evidence for the
wrong reason nonetheless would have been required to make the same
evidentiary ruling on the unpreserved alternative ground as a matter of
law, there is no reason that a reviewing court should be prevented from
substituting the legally compelled ground for the legally flawed ground.
The present case is altogether different, however, because it involves an
unpreserved alternative ground (cumulativeness) that ordinarily is discre-
tionary in nature; the state has not, and could not, argue that the trial court
here ‘‘would have been forced to rule’’ in its favor on this ground. See part
III of this opinion.
   5
     The state, as the appellant here, was not required to file notice in this
court that it intended to raise an alternative ground for affirmance pursuant
to Practice Book § 84-11, because that provision applies only to an appellee
who wishes to raise an alternative ground to affirm the judgment of the
Appellate Court in a certified appeal. See Vine v. Zoning Board of Appeals,
281 Conn. 553, 568 n.11, 916 A.2d 5 (2007). Rather, the state’s procedural
default arises from its failure at trial to preserve the legal issue for appellate
review. As Vine instructs, in cases in which Practice Book § 84-11 is inappli-
cable, ‘‘because the [appellant is] raising an [alternative] ground to affirm
the judgment of the trial court, the principles governing preservation of
claims raising [alternative] grounds for affirmance apply . . . .’’ Id.
   6
     The state contends that there was not a complete absence of corroborat-
ing evidence of the alleged sexual assaults, because B’s brother ‘‘testified
that he saw B in the defendant’s bedroom, putting on her belt.’’ We disagree
with the state’s characterization of the strength of the brother’s testimony
for two reasons. First, B’s brother did not witness any inappropriate interac-
tions at any time. Second, the brother’s testimony was confused, contradic-
tory and difficult to follow. The record reflects that the state continually
had to refresh the brother’s recollection with a sworn statement given prior
to trial, which was eventually admitted into evidence under State v. Whelan,
200 Conn. 743, 513 A.2d 86, cert. denied, 479 U.S. 994, 107 S. Ct. 597, 93 L.
Ed. 2d 598 (1986), after the brother testified that he could not remember
whether he had seen the defendant and B together on a second occasion.
We cannot agree with the state that the brother’s testimony materially
strengthened the state’s case against the defendant.
   We also disagree with the dissent’s suggestion that we are ‘‘attempt[ing]
to rationalize an innocent explanation for [the defendant’s] sneaky behavior
. . . [with] his teenage stepdaughter . . . .’’ See footnote 7 of the dissenting
opinion. We are not ‘‘rationalizing’’ anything; we are assessing the strength
of the state’s case on the basis of the evidence properly adduced at trial.
We fail to see how the testimony of B’s brother ‘‘significantly strengthened
the state’s case . . . .’’
   7
     The dissent’s assertion that the excluded evidence ‘‘did not pertain
directly to the veracity of the complainant or the allegations themselves’’
fails to acknowledge the direct bearing of this evidence on the assessment
of B’s credibility under the particular circumstances of this case. A reason-
able juror, unsure of whether to believe the allegations, could have used
the behavioral symptoms identified by Rosenberg as a guide to decide
whether the allegations of abuse were credible. This presumably is the very
reason that the state elicited that expert testimony in the first place. It is
unfair now, in assessing the potential significance of the evidence offered
by the defense for the very purpose of taking advantage of the state’s
inferential model, to say that the logic was weak and inconsequential.
   8
     This same point demonstrates the flaw in the dissent’s suggestion that
the defendant suffered no disadvantage because defense counsel was able
to present a jury argument based on the testimony of B and her mother
even without the testimony of P. It is inaccurate to posit that no harm
ensued from the trial court’s evidentiary ruling just because defense counsel
tried his best using the scraps of state-supplied evidence available to him.
The trial court’s erroneous evidentiary ruling was harmful because the
defense’s jury argument would have been materially and significantly
stronger had he been able to make use of P’s excluded testimony.
