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   STATE OF CONNECTICUT v. FERNANDO V.*
                (AC 37464)
                 Keller, Prescott and Mullins, Js.
     Argued October 20—officially released December 27, 2016

   (Appeal from Superior Court, judicial district of
Stamford-Norwalk, geographical area number twenty,
                    Holden, J.)
  Mary A. Beattie, assigned counsel, for the appel-
lant (defendant).
   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, assistant state’s
attorney, for the appellee (state).
                          Opinion

   PRESCOTT, J. The defendant, Fernando V., appeals
from the judgment of conviction, rendered following a
jury trial, of 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 General Statutes § 53a-71 (a) (4), and two
counts of risk of injury to a child in violation of General
Statutes § 53-21 (a) (2). The defendant claims on appeal
that the trial court improperly precluded him from pre-
senting testimony from the complainant’s boyfriend of
four years. In particular, the defendant argues that the
boyfriend’s testimony was relevant to counter the
state’s evidence that she had become more withdrawn
or exhibited other characteristics generally associated
with sexually abused young adults, as testified to by
the state’s expert witness, as well as to impeach testi-
mony that the defendant had tried to prevent the com-
plainant from associating with boys of her own age.
We agree that the boyfriend’s testimony improperly was
excluded by the court and that its exclusion was not
harmless error under the circumstances of this case.
Accordingly, we reverse the judgment of conviction and
order a new trial.1
   The jury reasonably could have found the following
facts. When the complainant, B, was nine years old, she
moved from Mexico to Stamford to live with her mother
and the defendant, her stepfather.2 At that time, B’s
younger brother, grandmother, and uncle also lived with
B’s mother and the defendant. The grandmother, how-
ever, soon returned to Mexico, and B was alone more
frequently with the defendant because her mother and
uncle were working. When B was approximately twelve
years old, the defendant, on more than one occasion,
touched her breasts, sometimes putting his hand inside
of B’s shirt and sometimes touching her over her shirt.
B confided in her mother that the defendant was ‘‘trying
to touch’’ her breasts. B’s mother confronted the defen-
dant, but he denied any inappropriate behavior, and
nothing further came of the matter.
   When she was thirteen, the family moved to a condo-
minium that the defendant and B’s mother had pur-
chased in Norwalk. B’s mother began to work more
hours, and B’s brother often would play outside with
friends, leaving B alone with the defendant. The defen-
dant continued to touch B as he had while in Stamford,
but he also began to have sexual intercourse with B.
The first time the defendant engaged in intercourse
with B, he was intoxicated and made her go into the
bathroom. He told her he wanted to ‘‘do it this one
time,’’ unbuckled his pants, and inserted his penis inside
B’s vagina.
  After that first incident, the defendant continued to
touch B inappropriately or have penile-vaginal sexual
intercourse with B several times a month. The assaults
generally occurred in his bedroom. On most occasions,
the defendant was sober and promised B that it would
be the last time. The assaults continued, however, until
B was seventeen years old. After the defendant began
having intercourse with B, B did not tell her mother
about the assaults because B was afraid of how her
mother would react, namely, that her mother would
blame B. At some point, however, B’s mother con-
fronted B about whether the defendant had ‘‘made [B]
have sex with him,’’ and B fully disclosed the details
of the assaults to her mother at that time.
   B’s mother contacted the police, and, following an
investigation, the defendant was arrested and charged.
A jury found the defendant guilty of two counts of
sexual assault in the second degree and two counts of
risk of injury to a child. He received a total effective
sentence of ten years of incarceration, followed by ten
years of special parole. This appeal followed.
   The defendant claims on appeal that the court
improperly precluded him from presenting testimony
from B’s longtime boyfriend, P. According to the defen-
dant, P’s testimony was relevant to demonstrate that
B had not exhibited any behavioral characteristics or
changes in personality consistent with those sometimes
exhibited by sexual assault victims, as described to the
jury by an expert witness offered by the state. The
defendant maintains that the testimony also was admis-
sible to contradict aspects of the testimony given by B
and her mother, both of whose credibility was central
to the state’s case against him. The defendant argues
that the court abused its discretion by excluding the
testimony from the jury without a proper basis for doing
so, and that the error was not harmless because the
excluded testimony, if presented to the jury, could have
had a substantial impact on the verdict. The state, by
contrast, asserts that P’s testimony was offered solely
as extrinsic evidence for impeachment purposes, and
that the court properly excluded the proffered testi-
mony because it was both collateral in nature and
entirely consistent with the testimony given by B and
her mother. We agree with the defendant that P’s testi-
mony was improperly excluded by the court and that
its exclusion was not harmless error.3
  The following additional facts are relevant to our
resolution of the defendant’s claim. During its case-in-
chief, the state presented testimony from a number of
witnesses. With respect to the issues before us on
appeal, the relevant testimony came from the state’s
expert witness on child sexual abuse and delayed dis-
closure, B, and B’s mother.
   The state’s expert witness, Larry M. Rosenberg, was
a licensed psychologist and clinical director of the Child
Guidance Center of Southern Connecticut, an outpa-
tient mental health clinic for children and adolescents.
In addition to testifying on the topic of delayed disclo-
sure in sexual assault cases, Rosenberg was asked by
the state to describe general behavioral characteristics
that often are associated with sexual assault victims.
Specifically, during the state’s examination of Rosen-
berg, the state asked whether there were general behav-
ioral characteristics associated with teenagers and
young adults who disclose sexual abuse. This collo-
quy followed:
   ‘‘[Rosenberg]: Well, if you were going to ask me, the—
in the majority of cases, being sexually abused tends
to most—most typically, but not always, reduce the
level of functioning of the person who has been victim-
ized. So, most typically, you see changes in their behav-
ior, but not always. It depends on how—the level at
which they were functioning previously.
  ‘‘[The Prosecutor]: And do symptoms of trauma
always occur within a given time frame after a disclo-
sure or after the traumatic incident itself?
   ‘‘[Rosenberg]: No. The diagnostic manual for the men-
tal health profession is specific about this, that post-
traumatic symptoms can occur as much—as many as
years following a traumatic event occurring.
                          ***
   ‘‘[The Prosecutor]: What are some symptoms of
trauma from child sexual assault, that you’ve seen, in
your practice, with victims who have made a dis-
closure?
  ‘‘[Rosenberg]: I previously mentioned disassociation,
the kind of psychic numbing that can go on. In a more
technical term, you know, depersonalization. Sort of
stepping outside of yourself, not recognizing, sort of,
be feeling a part of who you are anymore. That you’re
not the same person.
   ‘‘But in addition to that, typically, symptoms would be
bad dreams, flashbacks of the events that had occurred,
recurring memories of the event that had occurred,
changes in functioning with regard to sleep, with regard
to cognitive functioning, with regard to school func-
tioning.
  ‘‘Withdraw[al] is common. Depression is common.
Heightened anxiety, particularly in the face of anything
that is reminiscent of the event. But likewise, anything
that’s reminiscent of the event can cause the person
not necessarily to become overtly anxious, but to mani-
fest that anxiety by becoming more withdrawn and
more numb than they had been previously. And those
are some of the findings, typically.’’ (Emphasis added.)
  The mother testified during her direct examination
that she had observed some behavioral changes in B,
specifically indicating that, in the year prior to the
defendant’s arrest, B became more withdrawn than
usual and would stay in her room more often. She reiter-
ated those observations on cross-examination, indicat-
ing that when B was sixteen or seventeen years old,
she ‘‘stay[ed] in her room more often, locked up.’’ Both
B and her mother testified that she continued to do
well in school, continued to participate in activities that
she enjoyed, such as playing the flute and reading, and
worked part-time without any significant difficulties
or interruptions.
  In addition to eliciting testimony regarding B’s per-
sonality and behavioral characteristics during the time
period of the alleged assaults, the state also questioned
B and her mother regarding the defendant’s behavior
toward B’s male friends.4
  B explained that, beginning in her freshman year of
high school, the defendant would get angry if she tried
to ‘‘hang out’’ with male friends. He would make her
hang up the telephone if he discovered her talking to
a boy, and would question her about the conversation.5
Defense counsel was able to counter this testimony in
part during his cross-examination of B, eliciting from
B that she had dated two boys during high school,
including one during her freshman year, and that the
defendant had not objected to her dating either boy
and had no issues with them.6
   Similarly, during its examination of B’s mother, the
state also inquired whether the defendant was ‘‘any
different with regard to [B’s] friends as girls or her
friends as boys?’’ B’s mother responded in the affirma-
tive and, when asked how he was different, she stated,
consistent with B’s direct testimony: ‘‘Well, like, he
didn’t like for her to go out with male friends.’’ On
cross-examination, the following exchange occurred:
   ‘‘[Defense Counsel]: Now, you also testified that [the
defendant] had some issues with [B] talking to boys.
Is that correct?
  ‘‘[The Mother]: Yes.
  ‘‘[Defense Counsel]: How old was [B] when he raised
these concerns?
  ‘‘[The Mother]: Well, she was already in high school.
The same, sixteen, seventeen, where she wanted to go
out more and he was against that.
  ‘‘[Defense Counsel]: But isn’t it true that your daugh-
ter actually did have a boyfriend in freshman year in
high school?
  ‘‘[The Mother]: Yes.
  ‘‘[The Prosecutor]: Objection.
   ‘‘The Court: Objection’s overruled. Isn’t it true? Yes,
is the answer. The answer may stand.
  ‘‘[Defense Counsel]: And [the defendant] never
opposed that relationship. Isn’t that true?
  ‘‘[The Mother]: Well, he wouldn’t allow any friends
to show up at the house.
  ‘‘[Defense Counsel]: Did you ever witness [the defen-
dant] forbid this boy from coming to the home, ever?
  ‘‘[The Mother]: Well, yes. Once, when it was her birth-
day, we celebrated her eighteenth birthday and we
invited boys and girl friends, and he showed up and he
was very upset, asking why they were still at the house
and it was 10 at night.
   ‘‘[Defense Counsel]: But what I’m talking about . . .
is, [the defendant] really did not object to her having
a boyfriend in freshman year in high school, and you
didn’t witness him come between that relationship, at
all, did you?
  ‘‘[The Mother]: No. . . .
  ‘‘[Defense Counsel]: Isn’t it true that in [B]’s second
year in high school, she got into a relationship with a
second boy, his name [was P]. Isn’t that correct?’’
   At this point, the state objected on the ground of
relevancy and on the ground that the line of questioning
was precluded by our rape shield statute. See General
Statutes § 54-86f. The court asked defense counsel to
explain this line of questioning and whether it went to
the mother’s credibility. Defense counsel answered that
it did go to the mother’s credibility, but also to the
specific conduct of the defendant. The court overruled
the state’s objection but instructed defense counsel that
it did not want to get ‘‘bogged down in collateral issues.’’
The court instructed the mother to answer the question,
and the mother’s testimony resumed as follows:
  ‘‘[The Mother]: Yes.
  ‘‘[Defense Counsel]: And they—and she’s still in this
relationship with this boy. Isn’t that correct?
  ‘‘[The Mother]: Yes.
  ‘‘[Defense Counsel]: And this relationship’s been
going on since second year in high school, correct?
  ‘‘[The Mother]: Yes.’’
  On redirect, the state asked B’s mother if the defen-
dant was aware that B had a boyfriend in high school,
to which the mother answered: ‘‘Yes, I believe so.’’
   During his presentation of evidence, the defendant
attempted to call as a witness B’s longtime boyfriend,
P. Just a few questions into the defendant’s direct exam-
ination of P, defense counsel asked P how he knew B,
and P answered that they had been in a relationship
for the past four years. At that point, the court, sua
sponte, excused the jury. The court stated to counsel
that it was ‘‘not trying collateral matters’’ but indicated
to counsel that it would entertain an offer of proof.
The following testimony was then heard outside of the
presence of the jury:
   ‘‘[Defense Counsel]: When you say you’re in a rela-
tionship, 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
boyfriend 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.
  ‘‘[Defense Counsel]: And, did [the defendant] ever
forbid you from dating [B]?
  ‘‘[P]: No, he never did.
  ‘‘[Defense Counsel]: Did [the defendant] ever forbid
you from talking to [B]?
  ‘‘[P]: No, he never did.
  ‘‘[Defense Counsel]: Did [the defendant] ever forbid
you from seeing [B]?
  ‘‘[P]: No, he never did.
  ‘‘[Defense Counsel]: Did [the defendant] ever forbid
you from being alone with [B]?
  ‘‘[P]: No, he never did.’’
    The state indicated to the court that it objected to
the entirety of P’s proffered testimony. According to
the state, the testimony was not ‘‘relevant to the issue
at hand,’’ and it questioned whether P, as a layperson,
was ‘‘able to detect the signs of many of the kinds of
disorders counsel asked him about.’’ The court inquired
of the state whether P’s testimony impeached anyone
else’s testimony, recalling that B herself had testified
that she was attending school, getting good grades, and
still playing the flute. The court also stated that it did
not recall any testimony ‘‘of any disorders.’’ The state
responded that P’s testimony was not inconsistent with
any other testimony. The court asked defense counsel:
‘‘Is some fundamental basis going to be—fundamental
questions going to be asked of him to determine
whether or not he’s able to even discern those issues
you raised? Behavior disorders?’’ Defense counsel
offered the following response to the state’s objection
and to the court’s inquiries:
  ‘‘Yes, no, Your Honor, they go to, basically [P’s]
impression as being in a relationship with [B], whether
or not he’s noticed behavioral changes in [B]. And that
goes to impeach—it goes to the credibility of the—what
was testified to by [B’s mother], slightly of—that she
said her daughter, and there was a question, by the
state, of [B’s mother], whether she noticed any type of
depression in her daughter. And I believe [she]
answered in the positive. So, it goes to impeach [B’s
mother’s] statement, number one.
   ‘‘I would also submit to Your Honor that there’s been
information, by the expert of the state, which, basically,
has testified as an expert, that certain behavioral issues
come up when there [are] allegations made by
alleged victims.
  ‘‘And [P] can testify whether he’s seen those, or not,
as [a] layperson. Not as an expert. But as somebody
who’s in a relationship with her.
  ‘‘The only thing else I would add, Your Honor, is apart
from that, the questions that I asked regarding [the
defendant] directly go to testimony that has been made
by both [B] and [B’s mother] with respect to [the defen-
dant] objecting to [B] having any sort of relationship,
of any kind, with male persons.
  ‘‘And here is a young man who’s in a relationship,
for four years, who has testified that no such negativity
he has seen from [the defendant].’’
  In responding to defense counsel’s offer of proof, the
state reiterated that it did not believe that P’s testimony
directly contradicted anything that B or her mother had
stated in their testimony, and reasserted that it was
prejudicial to allow the defense to introduce any evi-
dence of a relationship or relationship history into the
case regardless of the defendant’s purported rationale
for pursuing it. The court then issued its ruling as set
forth in the following colloquy:
   ‘‘The Court: Anything further, counsel? This is extrin-
sic evidence to impeach one, whether or not [the defen-
dant] discouraged [P] from having a relationship with
his daughter? That’s correct?
  ‘‘[Defense Counsel]: Correct, that’s part of it.
   ‘‘The Court: And whether or not he saw anything
that—in terms of behavior, that has been testified to
as—may or may not be common with certain individu-
als. And you want that to come in, into evidence, as
well, through this witness?
  ‘‘[Defense Counsel]: Correct, Your Honor.
  ‘‘The Court: Anything further?
  ‘‘[Defense Counsel]: No, Your Honor.
   ‘‘The Court: The relevance of this testimony, the court
finds similar to that last testimony, is collateral, at best.7
   ‘‘Impeachment is not, by this evidence, extrinsic evi-
dence. It lends itself to—it’s likely to confuse the jurors.
It’s not probative of any issues.
  ‘‘And the testimony is clear, on the record, regarding
whether they believe the testimony of the mother and
the complainant as to the relationship in terms of
with boys.
  ‘‘And she testified she had been in a relationship for
four years. She has a boyfriend. She testified to that.
That’s before the jury already. That was—that’s there.
I don’t see any impeachment, based upon what I’ve
heard on this record, counsel.
   ‘‘Offer of proof has been made. It’s on the record,
should the matter be reviewed. It’s there for the Appel-
late Court to look at.
  ‘‘But before the jury, it’s confusing. It’s not probative,
and counsel, the objection is sustained.’’ (Emphasis
added; footnote added.) P’s proffered testimony was
not presented to the jury.
  During its rebuttal closing argument, the state
reminded the jury that it had heard evidence that B
became more withdrawn before the defendant’s arrest,
and that she was spending more time in her room.
The state also recounted Rosenberg’s testimony that
behavioral symptoms resulting from sexual assaults do
not always manifest themselves contemporaneously
with the assault.
   We begin our analysis by setting forth our standard
of review as well as legal principles pertinent to our
consideration of the defendant’s claim. ‘‘We review the
trial court’s decision to admit [or exclude] evidence, if
premised on a correct view of the law . . . for an abuse
of discretion. . . . We will make every reasonable pre-
sumption in favor of upholding the trial court’s ruling,
and only upset it for a manifest abuse of discretion.
. . . The trial court has wide discretion to determine
the relevancy [and admissibility] of evidence . . . .’’
(Internal quotation marks omitted.) State v. Alex B.,
150 Conn. App. 584, 593, 90 A.3d 1078, cert. denied, 312
Conn. 924, 94 A.3d 1202 (2014).
  Generally, ‘‘[e]vidence is admissible [if] it tends to
establish a fact in issue or to corroborate other direct
evidence in the case. . . . Unless excluded by some
rule or principle of law, any fact may be proved which
logically tends to aid the trier in the determination of
the issue.’’ (Internal quotation marks omitted.) State v.
McClendon, 199 Conn. 5, 8–9, 505 A.2d 685 (1986); see
also Conn. Code Evid. § 4-2 (‘‘[a]ll relevant evidence is
admissible, except as otherwise provided by the consti-
tution of the United States, the constitution of this state,
the [Connecticut] Code [of Evidence] or the General
Statutes’’).
   ‘‘The testimony of any witness may be contradicted
by the testimony of any other witness.’’ (Internal quota-
tion marks omitted.) State v. Warren, 14 Conn. App.
688, 699, 544 A.2d 209, cert. denied, 209 Conn. 805, 548
A.2d 442 (1988), cert. denied, 488 U.S. 1030, 109 S. Ct.
839, 102 L. Ed. 2d 971 (1989). Thus, ‘‘[a] witness may
be impeached by the introduction of contradictory evi-
dence of other witnesses as long as the evidence is in
fact contradictory . . . and that evidence does not
relate to a collateral matter. . . . A contradiction is not
collateral if it is relevant to a material issue in the case
apart from its tendency to contradict a witness. . . .
Whether extrinsic evidence contradicts testimony of a
witness so as to require its introduction into evidence
for impeachment purposes is within the trial court’s
discretion, subject to review only for abuse of discre-
tion.’’ (Citations omitted; internal quotation marks omit-
ted.) State v. Smith, 49 Conn. App. 252, 258–59, 714
A.2d 1243, cert. denied, 247 Conn. 914, 722 A.2d 809
(1998); see also State v. Carbone, 172 Conn. 242, 262,
374 A.2d 215 (impeaching witness on collateral matter
by extrinsic evidence not allowed), cert. denied, 431
U.S. 967, 97 S. Ct. 2925, 53 L. Ed. 2d 1063 (1977).
   Before turning to our review of the court’s ruling in
the present case, we first address the theory of admissi-
bility relied on by defense counsel in seeking to admit
P’s testimony. The theory of admissibility is germane
to our consideration of whether the court properly exer-
cised its discretion to exclude the proffered testimony
on the basis of a correct view of the law. ‘‘An appellant
who challenges on appeal a trial court’s exclusion of
evidence is limited to the theory of admissibility that
was raised before and ruled upon by the trial court. A
court cannot be said to have refused improperly to
admit evidence during a trial if the specific grounds for
admission on which the proponent relies never were
presented to the court when the evidence was offered.
. . . Error does not lie in the exclusion of evidence
claimed on an inadmissible ground even though it might
have been admissible had it been claimed on another
and different ground [at trial].’’ (Citations omitted; inter-
nal quotation marks omitted.) State v. Polynice, 164
Conn. App. 390, 401, 133 A.3d 952, cert. denied, 321
Conn. 914, 136 A.3d 1274 (2016).
  In its appellate brief and at oral argument before
this court, the state attempted to persuade us that P’s
testimony was offered and rejected solely as impeach-
ment evidence, purportedly to contradict the testimony
given by B, B’s mother, or the state’s child sexual abuse
expert. According to the state, P’s testimony as prof-
fered was wholly consistent with the testimony given
by B and her mother, and in no way conflicted with the
testimony of its expert, who testified as to the general
behavioral characteristics of victims of sexual abuse,
but who also testified that such characteristics were not
always present. The state insists that the court properly
ruled that P’s testimony was inadmissible for impeach-
ment purposes. To the extent that the state suggests that
the defendant’s theory of admissibility was so limited in
scope, we disagree.
   As the defendant has consistently maintained, both
on appeal and before the trial court, he expressly sought
to admit P’s testimony as direct evidence, both in
response to testimony by the state’s expert regarding
potential behavioral characteristics often exhibited by
sexual assault victims and to counter testimony by B’s
mother that B became withdrawn and stayed in her
room more often. The court was aware that the defen-
dant had a dual-pronged theory for the admissibility of
P’s testimony, and acknowledged as much on the
record. Specifically, the court asked defense counsel if
he was offering the testimony as extrinsic evidence to
impeach testimony that the defendant had discouraged
B’s relationship with P. Defense counsel answered yes,
‘‘in part,’’ suggesting that P’s testimony was contradic-
tory in other ways. (Emphasis added.) More import-
antly, the court also inquired whether defense counsel
sought to admit P’s testimony as direct evidence of B’s
behavior. Defense counsel answered in the affirmative.
Thus, rather than being offered solely for impeachment
purposes as the state asserts, P’s testimony was offered,
in large part, as direct evidence of B’s behavior, and the
court clearly understood that the evidence was being
offered for more than impeachment purposes.8 With
that in mind, we turn to our review of the court’s ratio-
nale for excluding P’s testimony.
   The court stated several reasons on the record for
excluding P’s testimony, all of which are belied by the
record and the particular circumstances of this case.
First, the court appears to have accepted the state’s
representation that P’s testimony was not, in fact, con-
tradictory of any prior testimony and also indicated
that the testimony was ‘‘collateral, at best’’ and, thus,
inadmissible as extrinsic evidence to impeach. The
court also stated several times that P’s testimony was
‘‘not probative of any issue,’’ suggesting the court failed
to grasp its relevance, which was clearly significant. In
this case, in which there was no third party witness to
the alleged abuse, no inculpatory statements by the
defendant, and no forensic evidence, the state’s case
against the defendant rested almost entirely on the
jury’s assessment of the credibility of B and her mother.
The state admitted as much in its closing argument,
telling the jury that ‘‘what this case really comes down
to is one simple question: who do you believe?’’ Such
evidence cannot properly be viewed either as collateral
in nature or not probative of the central issue of this
case. The trial court’s conclusions to the contrary sim-
ply are unfounded.
   It is indisputable that by questioning B and her mother
about B’s behavior and by eliciting testimony from its
expert witness about the behavioral characteristics
oftentimes displayed by sexual assault victims, the state
opened the door to the defendant’s proffered evidence.
The state cannot have it both ways: on the one hand
introducing 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. Although P was not qualified to give an expert
medical opinion about B, he could competently testify
as a layperson about her observable actions and behav-
iors, or lack thereof, and the jury was capable of
assessing his observations in that light. Furthermore,
although P was never directly asked during the proffer
whether B had become more withdrawn, the overall
nature of the questions asked, including whether B con-
tinued to participate at a high level in school and engage
in regular activities, were probative of B’s level of
engagement in normal activities generally and, if pre-
sented to the jury, P’s responses could have raised rea-
sonable doubt in the minds of the jury about whether
B had become withdrawn. The court excluded relevant
and material testimony from the jury by its wholesale
exclusion of P’s testimony.
   It is true that P’s proffered testimony could be viewed,
in part, as corroborative of B’s and her mother’s testi-
mony. For example, all three indicated that B had done
well in school and maintained social activities. Both B
and her mother, however, also testified that the defen-
dant acted differently when it came to B’s male friends.
Although neither testified that the defendant had any
negative interactions with respect to P in particular,
P’s testimony nonetheless was probative of the issue
of whether the defendant had acted in a negative fashion
toward B having male friends generally because P indis-
putably was a close male friend of B. P indicated that,
over a period of four years, the defendant had never
stopped P from talking to B, from being alone with B,
or from dating B. P was not asked to opine during the
proffer about the defendant’s reaction to other male
friends. Nevertheless, the jury reasonably could have
inferred from P’s positive interactions with the defen-
dant that the negative reaction the defendant allegedly
exhibited toward male friends of B, as testified to by B
and her mother, was less likely to be true. P’s testimony,
therefore, although not directly contradicting the testi-
mony of B and her mother that the defendant did not
like B to associate with boys of her own age, provided
a contrasting perspective that could have aided the
jury in assessing the defendant’s attitude toward male
friends. Furthermore, P’s testimony, taken as a whole,
suggested no negative changes in B’s behavior, which
was in contrast to B’s mother’s testimony that she had
become withdrawn and stayed in her room.
   If impeachment had been the sole purpose offered
for admitting P’s testimony, the court’s ruling excluding
that testimony may not have risen to an abuse of discre-
tion because its probative value for that purpose was
somewhat attenuated, entitling the decision to exclude
it to greater deference. We acknowledge, after all, that
there was a somewhat loose fit between P’s testimony
about his own treatment by the defendant as B’s boy-
friend, and the testimony of B and her mother regarding
the defendant’s attitude toward male friends generally.
Additionally, the defense was able to introduce through
cross-examination the fact that B had boyfriends in high
school and that the defendant was aware of them and
had ‘‘no issues’’ with them. P’s testimony might also
have been deemed somewhat cumulative in that regard,
although that was not one of the bases provided by the
court for excluding the testimony. See Conn. Code Evid.
§ 4-3 (proper to exclude relevant evidence if its admis-
sion would cause ‘‘undue delay, waste of time or need-
less presentation of cumulative evidence’’); but see
State v. Little, 138 Conn. App. 106, 122, 50 A.3d 360
(care should be taken not to exclude evidence that
merely overlaps with previously received evidence),
cert. denied, 307 Conn. 935, 56 A.3d 713 (2012).
   Nevertheless, as we have discussed, P’s testimony
was also offered for, and relevant 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. The court chose not to limit the scope of
P’s testimony, but simply precluded his testimony in
its entirety. In excluding P’s testimony, the court also
suggested that it would have been confusing to the jury.
It is axiomatic that the court has discretion to exclude
even relevant evidence when its probative value is out-
weighed by the danger of confusion of the issues or
misleading the jury. See Conn. Code Evid. § 4-3. The
proffered testimony, however, involved short answers
to concise questions about his interaction with and
observations of B as her boyfriend. As we have
explained, in a ‘‘he said, she said’’ type case such as
this, B’s actions and behavior were central to the jury’s
assessment of the evidence, which in large part con-
sisted of B’s testimony. There is nothing in P’s testimony
as proffered that was difficult to understand in the
context of the material issues, and, thus, presented little
or no danger of confusing or misleading the jury. For
all of these reasons, we conclude that the exclusion of
P’s testimony was an abuse of discretion.
   Having determined that the court improperly
excluded P’s testimony, we turn to whether that error
was harmful. ‘‘In order to establish reversible error on
an evidentiary impropriety . . . the defendant must
prove both an abuse of discretion and a harm that
resulted from such abuse. . . . [T]he proper standard
for determining whether an erroneous evidentiary rul-
ing is harmless should be whether the jury’s verdict was
substantially swayed by the error. . . . Accordingly, a
nonconstitutional error is harmless when an appellate
court has a fair assurance that the error did not substan-
tially affect the verdict.’’ (Citation omitted; internal quo-
tation marks omitted.) State v. Alex B., supra, 150 Conn.
App. 593. ‘‘[W]hether [an improper ruling] is harmless
in a particular case depends upon a number of factors,
such as the importance of the witness’ testimony in the
prosecution’s case, whether the testimony was cumula-
tive, the presence or absence of evidence corroborating
or contradicting the testimony of the witness on mate-
rial 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.’’ (Internal quotation
marks omitted.) State v. Eleck, 314 Conn. 123, 129, 100
A.3d 817 (2014). In other words, if the court improperly
excludes evidence that, if admitted, may have tended
substantially to influence the jury in light of the particu-
lar circumstances of that case, the error cannot be con-
sidered harmless. See State v. Wilson, 308 Conn. 412,
426, 64 A.3d 91 (2013).
  P’s testimony was important to the defense to the
extent that it helped to paint B as having been an ordi-
nary high school girl. Any evidence tending to show
that B failed to exhibit behaviors often attributed to
sexual assault victims or that dissuaded the jury from
believing B’s story generally, by implication, necessarily
would also decrease the likelihood in the eyes of the
jury that an assault had occurred.
   Moreover, we agree with the defendant that the
state’s case here was not an exceedingly strong one. As
previously stated, there was no corroborating physical
evidence or any witnesses to the alleged sexual assaults.
The case turned largely on whether the jury believed
B, and our review of her direct testimony and cross-
examination reveals many internal inconsistencies and
a lack of details. Moreover, the state injected behavioral
characteristics as an issue in the case through its expert,
Rosenberg, and the state was permitted to offer corrob-
orating evidence through B’s mother that B was with-
drawn, one of the characteristics that Rosenberg
specifically indicated was common in sexual abuse vic-
tims. P, who knew B well for many years, was the
only witness offered by the defendant to counter the
mother’s testimony, and, as such, exclusion of his testi-
mony certainly was damaging to the defense. The state
in its brief has offered little analysis with respect to
harmless error, simply restating its position that P’s
testimony ‘‘did not differ materially from that of B or
her mother’’ and arguing that exclusion of the testimony
‘‘had little effect on the jury, which had already heard
about B’s high school boyfriends, her good grades and
her activities.’’ The state fails to address P’s testimony
as it pertains to B’s behavioral characteristics, which
we have already established was a significant issue
before the jury, largely because of how the state chose
to prosecute this case. For example, the state chose to
highlight the mother’s testimony that B had become
‘‘withdrawn’’ to the jury during closing arguments,
reminding the jury of the expert’s testimony and that
withdrawal was a common characteristic of a sexual
assault victim. On the basis of our review of the record
as a whole as well as the evidence presented at trial, we
do not have a fair assurance that the court’s exclusion
of relevant evidence favorable to the defense did not
substantially affect the verdict.
  The judgment is reversed and the case remanded for
a new trial.
   In this opinion the other judges concurred.
   * In accordance with our policy of protecting the privacy interests of the
victims of sexual abuse 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.
   1
     The defendant also claims on appeal that he was deprived of a fair trial
because the prosecutor referred to the complainant as a ‘‘survivor’’ during
the state’s rebuttal closing argument. Because we reverse the judgment of
conviction and order a new trial on the basis of the defendant’s evidentiary
claim, we do not reach the defendant’s prosecutorial impropriety claim,
which is not likely to arise on retrial. See State v. T.R.D., 286 Conn. 191,
195, 942 A.2d 1000 (2008).
   2
     The defendant married B’s mother prior to B coming to the United States,
and he later adopted B and helped her petition for permanent residency.
   3
     As part of his claim, the defendant also asserts that the court’s evidentiary
error deprived him of his constitutional right to present a defense as pro-
tected by the sixth and fourteenth amendments to the United States constitu-
tion, and article first, § 8, of the Connecticut constitution. Because we agree
with the defendant that the court abused its discretion in excluding the
boyfriend’s testimony, the error was not harmless, and the defendant is
entitled to a new trial, we do not address the constitutional aspect of the
defendant’s claim. See State v. Genotti, 220 Conn. 796, 804, 601 A.2d 1013
(1992) (courts ordinarily should exercise restraint and eschew unnecessary
determinations of constitutional issues).
   4
     Presumably, the state sought to have the jury infer that any negative
behavior by the defendant regarding B’s interaction with male friends demon-
strated jealousy or that he was sexually possessive of B, either of which, if
believed, tended to make the sexual assault allegations against the defendant
more believable.
   5
     B testified as follows:
   ‘‘[The Prosecutor]: Did—as this was all occurring, did his behavior toward
you change, in any other ways?
   ‘‘[B]: His behavior?
   ‘‘[The Prosecutor]: You know, the way he was with you, you know, in
the house or about school—just anything, you know, because you were
living together all this time, right?
   ‘‘[B]: Mm-hmm.
   ‘‘[The Prosecutor]: So, anything else about your relationship that changed,
along with all this?
   ‘‘[B]: I wouldn’t, like, be able to hang out with guy friends because he
would—he wouldn’t like it, he would get mad.
   ‘‘[The Prosecutor]: So—can you describe that, a little bit more?
   ‘‘[B]: Like, if—let’s say, like, if he thought maybe I was talking on the
phone and he was a guy, he would make me hang up or he would ask
questions on why I was talking to a guy. When, like, if I talked to a girl, it
wouldn’t really matter.
   ‘‘[The Prosecutor]: And how old do you think you were, when that started?
   ‘‘[B]: Maybe freshman year of high school.
   ‘‘[The Prosecutor]: How old were you your freshman year?
   ‘‘[B]: Fourteen, fifteen.’’
   6
     The relevant colloquy on cross-examination was as follows:
   ‘‘[Defense Counsel]: . . . Now, you stated that [the defendant] didn’t
allow you—would get upset if you had boyfriends or male friends. Is that
correct?
   ‘‘[B]: Yes.
   ‘‘[Defense Counsel]: When did that—when did you notice that to start?
How old were you?
   ‘‘[B]: I think it started in high school.
   ‘‘[Defense Counsel]: What grade were you in, in high school, when you
perceived this type of reaction from [the defendant]?
   ‘‘[B]: I think I was a freshman.
   ‘‘[Defense Counsel]: Did he actually say anything to you?
   ‘‘[B]: He would just get mad. Like, if I was talking on the phone, he would
be, like—he would ask me who it was and if I said a boy, he was, like, well,
why are you talking to him.
   ‘‘[Defense Counsel]: Besides that, did he say anything further?
   ‘‘[B]: No.
   ‘‘[Defense Counsel]: Would he say anything further?
   ‘‘[B]: No, not that I remember.
   ‘‘[Defense Counsel]: Would he speak to you, after the phone call, more
extensively about that?
   ‘‘[B]: No.
   ‘‘[Defense Counsel]: Isn’t it true that you had a boyfriend your freshman
year in high school?
   ‘‘[B]: No, sophomore year.
   ‘‘[Defense Counsel]: You didn’t date a [NV]?
   ‘‘[B]: Well, yeah, for a short period of time.
   ‘‘[Defense Counsel]: But you dated him, correct?
   ‘‘[B]: Yes.
   ‘‘[Defense Counsel]: And you dated him in freshman year in high
school, correct?
   ‘‘[B]: Yes.
   ‘‘[Defense Counsel]: And why did you break up with him?
   ‘‘[B]: It just wasn’t working out.
   ‘‘[Defense Counsel]: Was—it wasn’t working out between you and [NV]—
   ‘‘[The Prosecutor]: Objection. What’s the relevance of a prior romantic
relationship?
   ‘‘The Court: Sustained. Next question please.
   ‘‘[Defense Counsel]: After that relationship, did you have another boy-
friend, after that?
   ‘‘[The Prosecutor]: Objection. I would renew the objection, Your Honor.
   ‘‘[Defense Counsel]: May I be heard, Your Honor?
   ‘‘The Court: Objection is sustained. Next question.
   ‘‘[Defense Counsel]: Did [the defendant] object to [NV], at all?
   ‘‘[B]: No.
   ‘‘[Defense Counsel]: Did [The defendant] ever have any issues with any
current boyfriends you have or have had, after that?
   ‘‘[B]: No.’’
   7
     P was the second witness the defense attempted to call. The court was
referring to the defendant’s first witness, the employer of B’s mother, JV,
who, in addition to employing her for many years, had befriended her
and helped her out in various circumstances. Except for some preliminary
information, the court also heard JV’s testimony outside the presence of
the jury. The testimony presented focused primarily on whether JV had
contacted a lawyer on behalf of B’s mother for the purpose of obtaining
money from the defendant in exchange for B not testifying in this case. JV
denied this allegation, which denial was entirely consistent with testimony
elicited from B’s mother during her cross-examination. When the court
questioned the purpose for JV’s testimony, defense counsel stated that he
wanted ‘‘to challenge the veracity of [JV’s] answers.’’ The court refused to
allow the jury to hear JV’s testimony. The court explained that the defendant
was bound by JV’s answers, which corroborated rather than contradicted
the testimony by B’s mother, and it concluded that the testimony was both
confusing and collateral in nature.
   8
     The defendant acknowledges that he also sought to admit P’s testimony
partly for impeachment purposes because P’s testimony was contrary to
the testimony by B and her mother that the defendant had acted in a negative
fashion toward B’s relationships with male friends, in addition to conflicting
with testimony by B’s mother that B had exhibited behavioral changes. As
we have previously indicated, if the jurors believed B and her mother regard-
ing the defendant’s alleged behavior toward B’s male friends, they might
reasonably have inferred that the defendant’s behavior manifested some
sexual obsession with B or, alternatively, demonstrated his concern that a
close relationship with a boy might result in a disclosure of his criminal acts,
either of which would tend to corroborate B’s allegations of sexual abuse.
