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   STATE OF CONNECTICUT v. KEVAN SIMMONS
                 (AC 37826)
                       Sheldon, Prescott and Bear, Js.

                                   Syllabus

Convicted of the crimes of assault in the first degree, criminal possession
    of a pistol or revolver and carrying a pistol without a permit in connection
    with the shooting of the victims, C and H, the defendant appealed to
    this court. He claimed, inter alia, that the state’s grant of immunity to
    H, in which the state agreed not to prosecute H for any act of perjury he
    committed while testifying for the state, was plain error that constituted
    structural error and, thus, warranted a new trial because it violated the
    public policy reflected in the statutory (§ 54-47a [b]) prohibition against
    immunizing perjured testimony. The state had granted H immunity in
    exchange for his testimony after he invoked his fifth and fourteenth
    amendment privilege against self-incrimination and refused to answer
    any questions by the state. After the statutory (§ 1-25) oath for testifying
    witnesses was administered to H, he testified that he could not recall
    any details of the shooting and did not identify the defendant as the
    shooter. The state then attempted to impeach H’s testimony with a
    previous statement he had made to his mother during a telephone conver-
    sation in which he identified the defendant as the shooter. The trial
    court admitted H’s statement to his mother as a prior inconsistent state-
    ment and ruled that the jury could use it only to evaluate H’s credibility,
    but not for substantive purposes. During closing argument to the jury,
    the prosecutor argued H’s statement to his mother should be treated
    as substantive evidence that the defendant was the shooter. Held:
1. The state’s promise to H of immunity from prosecution for any perjury
    he might commit in his testimony plainly violated the strong public
    policy contained in § 54-47a (b) against immunizing perjured testimony
    and undermined the perception of and confidence in the system of
    justice; a fraud was perpetrated on the jurors because, unbeknownst
    to them, H was permitted to swear to a meaningless oath under § 1-25
    that gave his testimony an indicium of reliability that was not present,
    as the immunity agreement meant he was free to lie without subjecting
    himself to legal jeopardy, and the record reflected that the trial court
    and the prosecutor either knew or should have known that the promise
    of immunity to H was improper.
2. The state’s improper grant of immunity to H warranted the exercise of
    this court’s supervisory authority over the due administration of justice,
    as the dearth of authority on the question of whether the improper grant
    of immunity constituted structural error, and this court’s practice of
    not deciding thorny constitutional questions when possible, made it
    unnecessary to decide whether the defendant’s constitutional rights
    were violated by the improper immunity agreement or whether the
    structural error doctrine was applicable.
3. This court’s exercise of its supervisory powers over the administration
    of justice to remand this case for a new trial made it unnecessary to
    resolve the difficult and close question of whether the defendant was
    harmed by H’s testimony; although the state’s motive in promising H
    broad and unlawful immunity was unknown, because the state presum-
    ably deemed H’s testimony necessary to the public interest, it was
    incongruous for the state to minimize the import of his testimony in
    order to argue that it was not harmful to the defendant, as the improper
    promise of immunity to H served as the mechanism to force him to
    testify, which thereafter presented the state with an opportunity to
    impeach him with his prior inconsistent statement to his mother and
    to improperly place that statement before the jury as substantive evi-
    dence that the defendant was the shooter.
4. The exercise of this court’s supervisory powers over the administration
    of justice to remand this case for a new trial was warranted under the
    circumstances here; the state’s improper immunity agreement with H
    gave him a license to commit perjury and, thus, directly implicated the
    perception of the integrity of the justice system, the existence of the
    sanction for perjury plays a critical role in the truth seeking process
    and helps to secure the defendant’s right to confront the witnesses
    against him, the reversal of the defendant’s conviction will help to ensure
    that such an unlawful promise will not be made by prosecutors in the
    future, it was necessary to send a clear message to trial courts that they
    have an affirmative obligation to intercede in circumstances where it
    appears that the state has offered a witness a license to lie during the
    trial, and because only the state has the ability to grant immunity to a
    witness, it is important that courts confine the use of that significant
    prosecutorial power to appropriate instances that do not further and
    unfairly disadvantage a defendant.
5. The state’s objection to this court’s exercise of its supervisory authority
    to reverse the defendant’s conviction was unavailing; it was not unclear
    that this court has supervisory power over the administration of justice,
    our Supreme Court having repeatedly stated that appellate courts pos-
    sess that power, the state’s contention that the defendant’s inaction at
    trial regarding the unlawful immunity agreement prevented this court
    from exercising its supervisory power to remedy such an egregious
    error on appeal was unavailing, as nothing in the record suggested
    that the defendant’s failure to challenge the propriety of the immunity
    agreement was due to a conscious trial strategy that amounted to a
    tactical waiver, and, after balancing all the interests involved, which
    included the extent of prejudice to the defendant, the emotional trauma
    to the victims or others likely to result from reliving their experiences
    at a new trial, the practical problems of memory loss and unavailability
    of witnesses after much time has elapsed, and the availability of other
    sanctions, this court was not convinced that it should not exercise its
    supervisory authority to reverse the defendant’s conviction.
    (One judge concurring in part and concurring in the judgment)
        Argued March 20, 2018—officially released March 26, 2019

                             Procedural History

  Substitute information charging the defendant with
two counts of the crime of assault in the first degree,
and with the crimes of criminal possession of a pistol
or revolver and carrying a pistol without a permit,
brought to the Superior Court in the judicial district of
Hartford and tried to the jury before Mullarkey, J.;
verdict and judgment of guilty, from which the defen-
dant appealed to this court; thereafter, the court, Hon.
Edward J. Mullarkey, judge trial referee, granted the
defendant’s motion for augmentation and rectification
of the record. Reversed; new trial.
  Laila M. G. Haswell, senior assistant public defender,
with whom, on the brief, was Lauren Weisfeld, chief
of legal services, for the appellant (defendant).
  Margaret Gaffney Radionovas, senior assistant
state’s attorney, with whom, on the brief, were Gail P.
Hardy, state’s attorney, and Chris A. Pelosi, senior
assistant state’s attorney, for the appellee (state).
                          Opinion

   PRESCOTT, J. In this criminal case, a witness for the
state, George Harris, was promised that he would not
be prosecuted for perjury even if he lied during his
testimony. The trial court acquiesced to this agreement,
despite recognizing that it ‘‘is probably against the pub-
lic interest . . . .’’ This appeal requires us to decide,
under the circumstances of this case, whether the
defendant, Kevan Simmons, is entitled to a new trial
because of this concededly unlawful promise. For the
reasons that follow, we conclude that this error was
so egregious in nature that it undermines public confi-
dence in the due administration of justice and that,
pursuant to our supervisory powers, the defendant
should be granted a new trial.
   The defendant appeals from the judgment of convic-
tion, rendered after a jury trial, of two counts of assault
in the first degree in violation of General Statutes § 53a-
59 (a) (5), criminal possession of a pistol or revolver
in violation of General Statutes § 53a-217c (a) (1), and
carrying a pistol without a permit in violation of General
Statutes § 29-35 (a). On appeal, the defendant claims,
in his initial brief, that the prosecutor committed impro-
prieties during closing argument that deprived him of
his right to a fair trial, including, among other things,
suggesting to the jury that it could consider as substan-
tive evidence a prior statement of Harris that was admit-
ted at trial only for impeachment purposes, in which
he identified the defendant as his assailant. We later
granted the defendant permission to file a supplemental
brief addressing an additional claim of prosecutorial
impropriety, namely, whether the defendant’s right to
due process was violated by the state’s failure to dis-
close to him, prior to trial, certain exculpatory evidence
relevant to the veracity of the detective who took a
statement from the defendant. See Brady v. Maryland,
373 U.S. 83, 87, 83 S. Ct. 1194, 10 L. Ed. 2d 215 (1963).
   After oral argument before this court, and on the
basis of our review of the record, we ordered the parties,
sua sponte, to file additional supplemental briefs
addressing an unpreserved claim of error not raised by
the parties, namely, ‘‘(1) whether the state’s agreement
not to prosecute George Harris for any future acts of
perjury committed while testifying for the state at the
defendant’s trial constituted plain error because it vio-
lates the public policy of this state against immunizing
perjured testimony; see General Statutes § 54-47a; see
also State v. Giraud, 258 Conn. 631, 634–35, 783 A.2d
1019 (2001); and (2) if so, whether such error was struc-
tural error or subject to harmless error analysis.’’ Each
party filed a supplemental brief. In its brief, the state
conceded that its grant of immunity to Harris was
improper. We later asked the parties to submit addi-
tional supplemental briefs addressing whether this
court should exercise its supervisory authority to
reverse the conviction. Because we exercise our super-
visory powers to order a new trial for the defendant
on the basis of the improper grant of immunity to Harris,
we do not reach the merits of the remaining claims
raised by the defendant.1
   The jury reasonably could have found the following
facts. A shooting occurred on Bedford Street in Hartford
on March 28, 2013, involving the defendant; Harris, his
friend; and Joaquin Cedeno. Specifically, at approxi-
mately 9:22 p.m. that day, the defendant and Harris
were walking through the Bedford mall, a term com-
monly used to describe a cluster of apartment buildings
on either side of Bedford Street, when they encountered
Cedeno standing on the front stoop of an apartment
building.
   Cedeno and the defendant began arguing. The argu-
ment quickly escalated into a physical fight. Harris tried
to break up the fight but was unsuccessful. During the
fight, the defendant pulled out a gun and pointed it at
Cedeno. Cedeno attempted to push the gun away from
himself, but the defendant fired several gunshots, hit-
ting both Cedeno and Harris. Cedeno, Harris, and the
defendant then all ran from the scene in different
directions.
  Officer Robert Fogg of the Hartford Police Depart-
ment, who was working nearby, received a dispatch
that gunshots had been fired at 137 Bedford Street.
Fogg drove to the location. When he arrived, he found
Harris, who had been shot in the leg, lying in an alleyway
just south of 137 Bedford Street. Harris did not name
his shooter and only told Fogg to relay a message to
his mother that he loved her. Harris was taken to a
hospital by ambulance.
   At 9:36 p.m., Officer Bartosz Kubiak was dispatched
to 378 Garden Street, a location close to the scene of
the shooting, after someone reported a serious assault
with a firearm. When Kubiak arrived, Cedeno was sitting
on the front steps of 378 Garden Street. Cedeno’s pants,
T-shirt, and sweatshirt were stained with blood, and it
appeared to Kubiak that Cedeno had been shot several
times on the right side of his body. Cedeno did not
indicate to Kubiak who had shot him. Cedeno was also
transported to a hospital. Kubiak searched the sur-
rounding area for evidence relating to the shooting but
did not find a weapon.
   Approximately ten minutes after the shooting, the
defendant returned to the scene of the shooting on
Bedford Street. He approached Fogg, and the two began
talking. Fogg knew that the defendant and Harris were
friends, so Fogg relayed to the defendant the message
Harris had asked Fogg to give to Harris’ mother. Fogg
also asked the defendant if he had seen anything with
respect to the shooting, and the defendant replied that
he had not.
  On March 30, 2013, two days after the shooting,
Detective Christopher Reeder spoke to Harris at the
hospital. Harris told Reeder that, on the night of the
shooting, he was walking through Bedford mall with a
person nicknamed ‘‘Ghost’’ when he heard gunshots
and realized he had been shot. He described the shooter
as a black male wearing black clothing. Reeder told
Harris that the police had video that captured the inci-
dent. Harris then rolled over in his hospital bed, sighed,
and said, ‘‘You ain’t even here; do what you gotta do.’’
Harris also told Reeder that he might have seen ‘‘Boo-
bie,’’ the nickname of Cedeno, at the shooting.
   That same day, Reeder also questioned Cedeno about
the shooting. Cedeno described his shooter as a black
male of average build, about five feet, eight inches tall,
and between twenty and twenty-five years old. Cedeno
also told Reeder that, on the night of the shooting, he
had been hanging out in Bedford mall when he was
approached by the shooter. Cedeno recalled that the
two got into an argument, during which the shooter
took out a gun and fired it at Cedeno. Cedeno told
Reeder that, after the gunfire broke out, he ran through
an alleyway between 133 and 135 Bedford Street, and
made it to Garden Street before he realized that he had
been shot and collapsed.
   On April 19, 2013, Harris was arrested on drug
charges. After reading Harris his Miranda2 rights,
Reeder began to question Harris about the shooting
incident on Bedford Street. Harris relayed to Reeder a
version of events similar to that which he had given
when he was questioned about the shooting in the hospi-
tal. Reeder then showed Harris a video comprised of
footage recovered from security cameras attached to
various apartments on Bedford Street (video) that
depicted the shooting. Harris once again pointed out
‘‘Ghost’’ in the video, but did not offer any additional
details about the shooting or identify himself on the
video.
  While incarcerated on the drug charges, Harris made
a phone call to his mother, during which he implicated
the defendant as his shooter. That call was recorded
by the correctional facility.
  On May 2, 2013, the defendant was arrested on
charges unrelated to the shooting of Harris and Cedeno.
That day, Reeder, Detective Renee LaMark-Muir, and
Detective Reginald Early interviewed the defendant.
Reeder showed the defendant the video of the shooting.
Afterward, Early presented the defendant with a state-
ment that he represented to the defendant had been
given to the police by Harris. Early, however, had fabri-
cated the entire statement in order to encourage the
defendant to confess that he was the shooter on the
belief that Harris had already inculpated him. In the
fabricated statement, Harris purportedly told the police
that Cedeno had attempted to rob him and the defen-
dant at gunpoint, and that the defendant had shot Ced-
eno in self-defense. The fabricated statement further
provided that the defendant also had shot Harris by
accident.3
   After Early read the fabricated statement to the defen-
dant, he became upset and began crying. Early then
began questioning the defendant about the shooting,
and the defendant gave a written statement in which
he admitted that he had shot Cedeno and Harris. Specifi-
cally, the defendant stated that Cedeno had attempted
to rob the defendant and Harris, and that the defendant
was forced to shoot Cedeno in self-defense but hit Har-
ris, too. The defendant also stated that he had found
the gun with which he shot Cedeno and Harris earlier
that day near a dumpster and, after the shooting, ran
and hid the gun before the police arrived. He stated that
he returned to Bedford Street after shooting Cedeno
and Harris to make sure that Harris was okay. Finally,
the defendant admitted that he was the person depicted
in the surveillance video speaking to Officer Fogg after
the shooting.
   On October 1, 2014, the state filed the operative sub-
stitute information, in which it charged the defendant
with two counts of assault in the first degree in violation
of § 53a-59 (a) (5), and one count each of criminal
possession of a pistol or revolver in violation of § 53a-
217c (a) (1) and carrying a pistol without a permit in
violation of § 29-35 (a). On October 8, 2014, the jury
trial began.
  On the first day of trial, the state called Harris as a
witness during its case-in-chief. Harris’ attorney was
present and advised Harris to invoke his fifth and four-
teenth amendment privilege against self-incrimination.
Harris did so and refused to answer any questions by
the state. A colloquy then ensued between the court,
the state, and defense counsel regarding a potential
grant of immunity for Harris.
   At that time, the state agreed not to prosecute Harris
for any crimes stemming from his involvement in the
March 28, 2013 shooting. His attorney rejected the
state’s offer of immunity as insufficient because if Har-
ris were to testify he could expose himself to federal
criminal liability with respect to the Bedford Street
shooting incident and might implicate himself in an
unrelated shooting in 2011 for which he had just
recently been served a warrant. The state represented
to the court that it would inquire as to whether it could
obtain federal immunity for Harris with respect to his
testimony at the defendant’s trial. The court then contin-
ued Harris’ appearance until the next day.
  On October 9, 2014, the state again called Harris as
a witness. Before Harris testified, the court inquired as
to whether the state and Harris had come to an
agreement regarding the grant of immunity. Harris’
counsel represented to the court that he believed an
agreement had been reached. The following exchange
then ensued between defense counsel, the court, and
the prosecutor:
   ‘‘[Harris’ Counsel]: And so [the grant of immunity]
includes transactional immunity to the events related
to the—on the day of the shooting, directly and indi-
rectly. It involves use immunity, so none of his words
could be used directly against him in this or any other
proceeding in state or federal court or anywhere else.
It also includes derivative use so that his words can’t
be used to investigate and then come up with other
evidence that can be used against him in any proceed-
ing. There are other issues that we have talked about
that I think need to be addressed.
  ‘‘The Court: Go ahead.
  ‘‘[Harris’ Counsel]: One is that the immunity statute
does not immunize a witness from committing per-
jury at the time.
  ‘‘The Court: It does not.
  ‘‘[Harris’ Counsel]: And my understanding is that
there is a tape recording or the prosecuting authority
believes that it has a tape recording of my client saying
something related to his testimony. So, I have concerns
about exposure to perjury, and my understanding is
that there has been an agreement that there wouldn’t
be any perjury prosecution related to my client’s testi-
mony today.
  ‘‘[The Prosecutor]: That’s correct, Your Honor.
   ‘‘The Court: Okay. Well, [counsel], I must compliment
you. I have been in the criminal justice system for forty-
two and one-half years. I’ve never heard of anybody
getting that agreement. But it’s an agreement the state
made. That’s their decision. Now, are we ready to tes-
tify?’’4 (Emphasis added.)
   Fully immunized, Harris was then administered the
oath for testifying witnesses by the clerk in the presence
of the jury. Although the oath taken by Harris was not
transcribed, the required contents of the oath are set
forth in General Statutes § 1-25, which provides that the
oath administered to witnesses shall be: ‘‘You solemnly
swear or solemnly and sincerely affirm, as the case may
be, that the evidence you shall give concerning this case
shall be the truth, the whole truth and nothing but the
truth; so help you God or upon penalty of perjury.’’
   Harris then testified that he had been on Bedford
Street on the night in question, and had been shot in
the leg and hospitalized. He indicated that he and the
defendant had been friends for eight years, and that he
also knew Cedeno, the other gunshot victim. The state
asked Harris a series of additional questions about his
recollections from the night he was shot, including who
he was with that night, what he and others were wear-
ing, and whether he knew the identity of the shooter.
Harris testified that he could not recall any details of
the night he was shot because he had been intoxicated.
He also testified that he was unable to identify anyone,
including himself, from the videotape of the incident,
which the state played for him in court, stopping it at
various points to ask questions.5 He did not name the
defendant as his shooter.
   The state, however, attempted to impeach Harris’
testimony that he did not know the identity of his
shooter by questioning him about the May 6, 2013 tele-
phone call he made to his mother while he was incarcer-
ated, during which he identified the defendant as the
person who shot him. After establishing that he had
signed a consent form when he was incarcerated
acknowledging that his telephone calls would be
recorded, the state asked Harris if he had talked to his
mother about this case. In particular, the prosecutor
asked him if he had told his mother that he was not
going to cooperate with the police because he believed
that he could only receive a thirty day sentence for
refusing to testify, the defendant was in a holding cell
nearby, and the police had shown him a videotape of
‘‘this nigga shooting at me and this dude.’’ He repeatedly
responded that he could not remember what he had
told his mother, including whether he had told her that
he could identify both himself and the defendant in the
surveillance videotape he was shown by the police. At
this point, the jury was excused so that the state could
play the recording of the telephone call for the witness
in an attempt to refresh his recollection.
  Outside the presence of the jury, the following collo-
quy between the court and the prosecutor about the
immunity agreement ensued during a discussion of the
admissibility of the call from Harris to his mother:
  ‘‘[The Prosecutor]: The state will be offering [the
recording of the telephone call] as a prior inconsistent
statement by Mr. Harris. Now, if Mr. Harris—
  ‘‘The Court: Well, are you sure that he does not have
early onset dementia? Because for a young man, his
memory’s shot.
  ‘‘[The Prosecutor]: Well, this is the way you could
refresh his memory, Your Honor.
  ‘‘The Court: Well, you’re the one who agreed not to
prosecute him for perjury.
  ‘‘[The Prosecutor]: I agree.
  ‘‘The Court: Which is probably against the public
interest, but I didn’t step in.
  ‘‘[The Prosecutor]: There’s a lot of issue with public
interest in this case.
  ‘‘The Court: I must say this amount of perjury actu-
ally offends me.’’ (Emphasis added.)
  Harris was then questioned before the jury about
what he had said to his mother during the prison phone
call. After Harris denied having told his mother that he
could identify himself and the defendant in the video-
tape he had been shown by the police and that he could
not remember making such a statement, portions of
the audiotaped recording of the phone call were played
to the jury without objection.
   After the state had completed its direct examination
of Harris, the court gave the jury the following instruc-
tion: ‘‘Ladies and gentlemen, just as I gave you the
instruction a few minutes ago on prior misconduct by
a witness, evidence has been presented through this
witness that statements made outside the court are
inconsistent with some of his trial testimony. You
should consider that out-of-court evidence only as it
relates to his credibility. It’s not substantive evidence.
In other words, you consider it evidence as you would
any other evidence inconsistent with his conduct in
determining the weight to give to his testimony in
court.’’
   Despite the court’s instruction that the phone call
between Harris and his mother could not be used for
substantive purposes, the prosecutor, during closing
argument, drew the jury’s attention to specific portions
of that phone call, arguing as follows: ‘‘One point in
his testimony that he’s talking to his mom: First, I think
I am being charged with everything [the defendant] is.
Cop told me the warrant is for not cooperating, and
I’m like, yeah, I’ll take that. Makes sense. If you woulda
seen the video they showed me, I coulda got charged
with the same thing he got charged with. They showed
me the video. When they first showed me the video,
I’m telling them: I don’t know who that is. That’s why
they saying I won’t cooperate. I’m like, that’s me. That’s
Boobie. I don’t know who that is. He like, who’s that?
That’s Ghost. That’s Ghost. They showed everything.
When I sat down, when I couldn’t move, they showed
[the defendant] walked up to me. Then they showed
him run off. Then they show this girl run out, tie my
leg up. They showed the whole thing.
   ‘‘They smacked him with the charges right there. He
testified that they’re arrested at the same time, that
they were at [the] Hartford lockup at the police depart-
ment, and they were placed in cells next to each other.
They smacked him with the charges right there. They
had us together. They really put us together and this
‘n’ shot me. They just got us together. They don’t care.
And then he laughs. I’m in a holding cell. I don’t know
how he seen me. I’m asleep. He seen me. They put him
in a cell like two cells down. It’s like, one, two in the
morning. All I hear is: George. George. Come on, man.
I know you hear me. I know you hear me. I just seen
you. I just seen you. I’m like, this ‘n’ really trying to
talk to me? I’m in jail ‘cause of him right now ‘cause
he shot me in the leg.
  ‘‘That’s testimony, ladies and gentlemen. That’s not
given to police or the state’s attorney’s office. Now, I’m
going to—now, that’s another factor, as I said. [The
defendant]—Mr. Harris places him at the scene as the
shooter.’’ (Emphasis added.) Thus, the state attempted
to make substantive use of Harris’ recorded phone call
to his mother despite the fact that the court had admit-
ted it only for impeachment purposes and not for the
truth of any of Harris’ statements made during the
phone call.
   On October 14, 2014, the jury returned a verdict of
guilty on all counts of the operative substitute informa-
tion. On January 6, 2015, the court sentenced the defen-
dant to twenty-three years of incarceration followed
by ten years of special parole. This appeal followed.
Additional facts and procedural history will be set forth
as necessary.
   The defendant claims that the state’s agreement not
to prosecute Harris for any act of perjury he committed
while testifying for the state during the defendant’s trial
constituted plain error because it clearly violated a pub-
lic policy against immunizing perjured testimony. This
improper grant of immunity, the defendant contends,
constitutes structural error that obviates the need to
engage in harmless error analysis and warrants a new
trial. In the alternative, the defendant argues that, if
harmless error analysis applies, the state has failed to
meet its burden to show that the error was harmless
beyond a reasonable doubt. Finally, the defendant
argues that we should exercise our supervisory author-
ity over the administration of justice to reverse his
conviction and order a new trial.
  The state contends that, although there was error,
that error was not structural in nature and did not cause
the defendant manifest injustice. Additionally, the state
argues that this court should not exercise its supervi-
sory powers over the administration of justice to
reverse the conviction and order a new trial.
  Although we ultimately decide to reverse the defen-
dant’s conviction and order a new trial pursuant to
our supervisory authority, it is, in our view, helpful to
discuss the question of structural error and harm to
explain why we choose to resolve the case by resort
to our supervisory powers rather than by employing
the structural error doctrine or through an evaluation
of harm to the defendant. See State v. Rose, 305 Conn.
594, 606–607, 46 A.3d 146 (2012).
                             I
   We begin with a discussion of the plain error doctrine.
It is axiomatic that an unpreserved claim of error, i.e.,
one that was neither distinctly raised before nor decided
by the trial court, may be considered pursuant to the
plain error doctrine. ‘‘[The plain error] doctrine, codi-
fied at Practice Book § 60-5, is an extraordinary remedy
used by appellate courts to rectify errors committed at
trial that, although unpreserved, are of such monumen-
tal proportion that they threaten to erode our system
of justice and work a serious and manifest injustice on
the aggrieved party. [T]he plain error doctrine . . . is
not . . . a rule of reviewability. It is a rule of reversibil-
ity. That is, it is a doctrine that this court invokes in
order to rectify a trial court ruling that, although either
not properly preserved or never raised at all in the trial
court, nonetheless requires reversal of the trial court’s
judgment, for reasons of policy. . . . In addition, the
plain error doctrine is reserved for truly extraordinary
situations [in which] the existence of the error is so
obvious that it affects the fairness and integrity of and
public confidence in the judicial proceedings. . . .
Plain error is a doctrine that should be invoked spar-
ingly. . . .
   ‘‘An appellate court addressing a claim of plain error
first must determine if the error is indeed plain in the
sense that it is patent [or] readily discernable on the
face of a factually adequate record, [and] also . . .
obvious in the sense of not debatable. . . . This deter-
mination clearly requires a review of the plain error
claim presented in light of the record.
   ‘‘Although a complete record and an obvious error
are prerequisites for plain error review, they are not,
of themselves, sufficient for its application. . . . [I]n
addition to examining the patent nature of the error,
the reviewing court must examine that error for the
grievousness of its consequences in order to determine
whether reversal under the plain error doctrine is appro-
priate. A party cannot prevail under plain error unless
it has demonstrated that the failure to grant relief will
result in manifest injustice. . . . In State v. Fagan, [280
Conn. 69, 87, 905 A.2d 1101 (2006), cert. denied, 549
U.S. 1269, 127 S. Ct. 1491, 167 L. Ed. 2d 236 (2007)],
[our Supreme Court] described the two-pronged nature
of the plain error doctrine: [An appellant] cannot prevail
under [the plain error doctrine] . . . unless he demon-
strates that the claimed error is both so clear and so
harmful that a failure to reverse the judgment would
result in manifest injustice.’’ (Citation omitted; empha-
sis in original; internal quotation marks omitted.) State
v. Sanchez, 308 Conn. 64, 76–78, 60 A.3d 271 (2013).
   The state concedes that its improper immunity
agreement with Harris violated the first prong of the
plain error doctrine because the error is discernible on
the face of a factually adequate record. Perhaps more
significantly, the record reflects that the trial court and
the prosecutor either knew or should have known that
the promise of immunity to Harris by the state was
improper6 and yet, the court permitted Harris to testify
pursuant to an unlawful agreement that he could not
be prosecuted for perjury even if he lied during his
testimony. Despite the state’s concession, it is
important for us to explicate fully the reasons why such
an agreement violates public policy and undermines
confidence in our judicial system.
   ‘‘[A] primary function of a criminal trial is to search
for the truth. . . . The trial court has a duty to preside
at a trial and to take appropriate actions, when neces-
sary, that promote truth at a trial.’’ (Citation omitted.)
State v. Kirker, 47 Conn. App. 612, 617, 707 A.2d 303,
cert. denied, 244 Conn. 914, 713 A.2d 831 (1998); see
also State v. Mendoza, 119 Conn. App. 304, 321, 988
A.2d 329 (court required ‘‘to balance the defendant’s
interest in a fair proceeding with a trial’s fundamental
and ever present search for the truth’’), cert. denied,
295 Conn. 915, 990 A.2d 868 (2010); Riley v. Goodman,
315 F.2d 232, 234 (3d Cir. 1963) (‘‘We have long aban-
doned the adversary system of litigation which regards
opposing lawyers as players and the judge as a mere
umpire whose only duty is to determine whether infrac-
tions of the rules of the game have been committed.
. . . A trial is not a contest but a search for the truth
so that justice may properly be administered.’’ [Cita-
tion omitted.]).
   ‘‘From ancient times it has ever been held essential
that witnesses in court proceedings swear or affirm
before giving evidence.’’ (Internal quotation marks
omitted.) Cologne v. Westfarms Associates, 197 Conn.
141, 153, 496 A.2d 476 (1985). Our statute criminalizing
perjury plays a critical role in the search for the truth
at trial because it significantly deters a witness who
takes an oath or an affirmation from testifying falsely
at a time when the witness’ testimony will significantly
impact the rights of a defendant. See General Statutes
§ 53a-156 (a); Maryland v. Craig, 497 U.S. 836, 845–46,
110 S. Ct. 3157, 111 L. Ed. 2d 666 (1989) (confrontation
clause ‘‘insures that the witness will give his statements
under oath—thus impressing him with the seriousness
of the matter and guarding against the lie by the possibil-
ity of a penalty for perjury’’ [internal quotation marks
omitted]);7 State v. Tye, 248 Wis. 2d 530, 540–41, 636
N.W.2d 473 (2001) (‘‘[t]he purpose of an oath or affirma-
tion is to impress upon the swearing individual an
appropriate sense of obligation to tell the truth . . .
by creating liability for perjury’’ [footnotes omitted]);
58 Am. Jur. 2d 884–86, 888–89, Oath and Affirmation
§§ 1, 5 and 6 (2012).
   Section 54-47a sets forth the requirements regarding
the grant of immunity to a witness who has refused to
testify pursuant to his privilege against self-incrimina-
tion guaranteed by the fifth and fourteenth amendments
to the United States constitution. Section 54-47a (a)
provides in relevant part that ‘‘[w]henever in the judg-
ment of the Chief State’s Attorney, a state’s attorney
or the deputy chief state’s attorney, the testimony of
any witness . . . in any criminal proceeding involving
. . . felonious crimes of violence . . . is necessary to
the public interest, the Chief State’s Attorney, the state’s
attorney, or the deputy chief state’s attorney, may, with
notice to the witness, after the witness has claimed his
privilege against self-incrimination, make application
to the court for an order directing the witness to testify
or produce evidence subject to the provisions of this
section.’’ (Emphasis added.)
   Section 54-47a (b) provides in relevant part that
‘‘[u]pon the issuance of the order such witness shall
not be excused from testifying . . . on the ground that
the testimony or evidence required of him may tend to
incriminate him or subject him to a penalty or forfeiture.
No such witness may be prosecuted or subjected to
any penalty or forfeiture for or on account of any trans-
action, matter or thing concerning which he is com-
pelled to testify or produce evidence, and no testimony
or evidence so compelled, and no evidence discovered
as a result of or otherwise derived from testimony or
evidence so compelled, may be used as evidence against
him in any proceeding, except that no witness shall
be immune from prosecution for perjury or contempt
committed while giving such testimony or producing
such evidence . . . .’’8 (Emphasis added.)
   In State v. Giraud, supra, 258 Conn. 634–38, our
Supreme Court considered a related immunity issue.
Specifically, the defendant in Giraud claimed that the
trial court improperly had failed to grant a defense
witness immunity from prosecution. Id., 634. Prior to
that witness being sworn, the defendant had moved
that the state be compelled to grant the witness immu-
nity with respect to his testimony, ‘‘with the exception
[of] any perjury committed by him . . . .’’ (Internal
quotation marks omitted.) Id. In rejecting the defen-
dant’s claim, our Supreme Court noted that ‘‘[t]he
request did not distinguish between perjury committed
before [the witness] was granted immunity and perjury
committed by him when testifying after such a grant
of immunity. Immunity, of course, may not be a license
to lie while giving immunized testimony.’’ (Emphasis
added; internal quotation marks omitted.) Id., 634–35.
Similarly, the Supreme Court of the United States has
consistently held that grants of immunity cannot extend
to future perjurious testimony given by a witness—i.e.,
perjury committed during the course of the immunized
testimony. See United States v. Apfelbaum, 445 U.S.
115, 127–30, 100 S. Ct. 948, 63 L. Ed. 2d 250 (1980); see
also Glickstein v. United States, 222 U.S. 139, 143, 32
S. Ct. 71, 56 L. Ed. 128 (1911) (testimony given under
a license to commit perjury is not ‘‘testimony in the
true sense of the word’’).
  In the present case, it is undisputed that the immunity
obtained by Harris included immunity from prosecution
for any perjury that Harris might commit while testi-
fying as a witness for the state against the defendant.
The state promised immunity to overcome Harris’ invo-
cation of his fifth and fourteenth amendment privilege
against self-incrimination and to force him to testify.
The promise plainly violated the strong public policy
that is reflected in the statutory prohibition contained
in § 54-47a (b).9
   A jury is entitled to assume that the statements of a
witness who testifies at trial ‘‘carr[y] the sanction of
the oath which [he or] she ha[s] taken . . . .’’ Ruocco
v. Logiocco, 104 Conn. 585, 591, 134 A. 73 (1926). In the
present case, the transcript of the proceedings indicates
that Harris was sworn in by the clerk in the presence
of the jury. Without any knowledge of the improper
immunity agreement, the jury presumably believed that
Harris was testifying under the sanction of the oath
that he took ‘‘upon the penalty of perjury.’’ General
Statutes § 1-25. Unbeknownst to the jury, however, his
oath had no significance because Harris knew that the
immunity agreement meant he was free to lie without
subjecting himself to legal jeopardy. In other words, a
fraud was perpetrated on the jurors by permitting Harris
to swear to a meaningless oath that gave his testimony
an indicium of reliability that was not in fact present.
In sum, the improper grant of immunity violates public
policy and undermines the perception of and confi-
dence in our system of justice.
                             II
   Having explained why the grant of immunity in this
case violates public policy, we next turn to the question
of whether this impropriety constitutes structural error
that obviates the need to engage in harmless error analy-
sis to determine whether the defendant suffered a mani-
fest injustice. The state contends that the improper
grant of immunity does not constitute a structural error
that would excuse the defendant from establishing that
it caused a manifest injustice to him because the harm
suffered by the defendant, if any, is not ‘‘unquantifiable
or indeterminate’’ and was not of ‘‘such pervasiveness
or magnitude’’ to rise to the level of structural error.
   This question appears to be a matter of first impres-
sion, as our research has not revealed any reported
cases addressing it.10 The United States Supreme Court
recently set forth a comprehensive discussion of the
structural error doctrine: ‘‘The purpose of the structural
error doctrine is to ensure insistence on certain basic,
constitutional guarantees that should define the frame-
work of any criminal trial. Thus, the defining feature
of a structural error is that it affect[s] the framework
within which the trial proceeds, rather than being sim-
ply an error in the trial process itself. . . . For the same
reason, a structural error def[ies] analysis by harmless
error standards. . . .
  ‘‘The precise reason why a particular error is not
amenable to that kind of analysis—and thus the precise
reason why the Court has deemed it structural—varies
in a significant way from error to error. There appear
to be at least three broad rationales.
   ‘‘First, an error has been deemed structural in some
instances if the right at issue is not designed to protect
the defendant from erroneous conviction but instead
protects some other interest. This is true of the defen-
dant’s right to conduct his own defense, which, when
exercised, usually increases the likelihood of a trial
outcome unfavorable to the defendant. . . . That right
is based on the fundamental legal principle that a defen-
dant must be allowed to make his own choices about
the proper way to protect his own liberty. . . . Because
harm is irrelevant to the basis underlying the right, the
Court has deemed a violation of that right structural
error. . . .
   ‘‘Second, an error has been deemed structural if the
effects of the error are simply too hard to measure. For
example, when a defendant is denied the right to select
his or her own attorney, the precise effect of the viola-
tion cannot be ascertained. . . . Because the govern-
ment will, as a result, find it almost impossible to show
that the error was harmless beyond a reasonable doubt
. . . the efficiency costs of letting the government try
to make the showing are unjustified.
   ‘‘Third, an error has been deemed structural if the
error always results in fundamental unfairness. For
example, if an indigent defendant is denied an attorney
or if the judge fails to give a reasonable-doubt instruc-
tion, the resulting trial is always a fundamentally unfair
one. See Gideon v. Wainwright, 372 U.S. 335, [343–45],
83 S. Ct. 792, 9 L. Ed. 2d 799 (1963) (right to an attorney);
Sullivan v. Louisiana, 508 U.S. 275, 279, 113 S. Ct. 2078,
124 L. Ed. 2d 182 (1993) (right to a reasonable-doubt
instruction). It therefore would be futile for the govern-
ment to try to show harmlessness.
   ‘‘These categories are not rigid. In a particular case,
more than one of these rationales may be part of the
explanation for why an error is deemed to be structural.
. . . For these purposes, however, one point is critical:
An error can count as structural even if the error does
not lead to fundamental unfairness in every case. See
[United States v. Gonzalez-Lopez, 548 U.S. 140, 149 n.4,
126 S. Ct. 2557, 165 L. Ed. 2d 409 (2006)] (rejecting as
inconsistent with the reasoning of our precedents the
idea that structural errors always or necessarily render
a trial fundamentally unfair and unreliable . . . [cita-
tions omitted; internal quotation marks omitted]).11
Weaver v. Massachusetts,        U.S.     , 137 S. Ct. 1899,
1907–1908, 198 L. Ed. 2d 420 (2017); see also State v.
Latour, 276 Conn. 399, 410–12, 886 A.2d 404 (2005);
State v. Lopez, 271 Conn. 724, 733–34, 859 A.2d 898
(2004).
   On one hand, the error in this case reasonably can
be characterized as affecting the structural integrity of
the entire trial. Permitting the testimony at a criminal
trial of even a single witness who does not face the
sanction of a prosecution for perjury undermines the
truth seeking purpose of a trial. On the other hand, the
error in this case, while egregious in nature, was related
directly to a single witness who testified during a dis-
tinct portion of the trial and did not necessarily affect
the entire proceeding.
   The error here does not fall within the first general
category of structural errors because it does not impli-
cate a right, similar to the defendant’s right to conduct
his own defense, that is separate and distinct from legal
protections that are designed to protect against errone-
ous convictions. Moreover, the second category of
structural error, i.e., those errors the effect of which
are simply too difficult to measure, is not applicable
because there may be instances in which the effect
of the improper grant of immunity on the verdict is
measurable and quantifiable. For purposes of illustra-
tion, imagine a case in which twenty-five witnesses
identify the defendant as the perpetrator but one of the
witnesses testifies after having been given immunity
from a perjury prosecution for his testimony. In such
a scenario, a reviewing court could reasonably conclude
that, in light of the testimony of the twenty-four other
witnesses, the testimony of the one improperly immu-
nized witness was harmless beyond a reasonable doubt
and did not cause the defendant to suffer a manifest
injustice.
   Indeed, we are aware that, at first blush, the unlawful
immunity agreement in the present case appears analo-
gous to instances in which a witness testifies at trial
without properly having been sworn in through the
administration of an oath. Under existing federal juris-
prudence, testimony by an unsworn witness is not con-
sidered structural error and, in fact, courts have deemed
such claims of error forfeited if not raised before the
trial court. See, e.g., United States v. Watson, 611 Fed.
Appx. 647, 661–62 (11th Cir. 2015), cert. denied,
U.S.      , 136 S. Ct. 1212, 194 L. Ed. 2d 215 (2016).
Although the two errors are similar because both
involve testimony given by a witness unencumbered by
the legal sanction of an oath, the situation in the present
case involves a far more insidious error, warranting a
different analysis. The failure to swear in a witness
arising in these federal cases presumably is the product
of inadvertence. Furthermore, the error typically occurs
in the presence of the jury, which may be aware that
the oath was not given and can evaluate the unsworn
testimony accordingly. In the present case, by contrast,
the jury was deceived into believing that Harris was
testifying under the penalty of perjury.
  The error in this case is more akin to those arising
in the third category of structural errors, i.e., those
errors, such as the failure to give a reasonable doubt
instruction, that always result in fundamental
unfairness to a defendant. The defendant’s sixth and
fourteenth amendment right to confront the witnesses
against him is vitiated in circumstances in which a wit-
ness does not testify under the penalty of perjury.12 As
the United States Supreme Court stated in Maryland
v. Craig, supra, 497 U.S. 836, ‘‘[t]he central concern of
the [c]onfrontation [c]lause is to ensure the reliability
of the evidence against a criminal defendant by sub-
jecting it to rigorous testing in the context of adversary
proceeding before the trier of fact. . . . [T]he right
guaranteed by the [c]onfrontation [c]lause includes not
only a personal examination [of the witness], but also
. . . insures that the witness will give his statements
under oath—thus impressing him with the seriousness
of the matter and guarding against the lie by the possibil-
ity of a penalty for perjury . . . .’’ (Citations omitted;
internal quotation marks omitted.) Id., 845–46.
   In light of the dearth of authority on the question of
whether the error in this case is structural in nature,
and consistent with our practice of not deciding thorny
constitutional questions when possible, we conclude
that it is unnecessary to decide whether the defendant’s
constitutional rights were violated by the improper
immunity agreement or whether the structural error
doctrine applies in this case. Instead, for the reasons
we will set forth in part IV of this opinion, we choose
to exercise our supervisory powers over the administra-
tion of justice to order a new trial in this case.
  Indeed, our Supreme Court has taken a similar
approach in several cases. In State v. Padua, 273 Conn.
138, 178–79, 869 A.2d 192 (2005), our Supreme Court
declined to decide whether principles of double jeop-
ardy required an appellate court to adjudicate the defen-
dant’s insufficiency of the evidence claim before
addressing the defendant’s other claims on appeal.
Instead, the court in Padua, exercising its supervisory
powers, concluded that it was appropriate to impose a
rule requiring review of insufficiency of the evidence
claims first, even in the absence of a conclusion that
the defendant’s constitutional rights would be violated
otherwise. Id.; see also State v. Coleman, 242 Conn.
523, 534, 700 A.2d 14 (1997) (exercising supervisory
powers in lieu of deciding state constitutional claim).
   In State v. Rose, supra, 305 Conn. 607–14, our
Supreme Court exercised its supervisory powers to
reverse the conviction of a defendant and order a new
trial because the trial court had compelled the defen-
dant to wear identifiable prison clothing during his jury
trial. In doing so, the Supreme Court eschewed the need
to determine whether the trial court’s actions consti-
tuted structural error or whether the defendant was
prejudiced under the circumstances of the case. Simi-
larly, for the reasons we will discuss in this opinion,
we conclude that the error in the present case warrants
an exercise of our supervisory authority over the due
administration of justice, making it unnecessary to
decide whether the error is structural in nature.
                            III
   The question of whether the defendant suffered a
manifest injustice as a result of the state’s improper
promise of immunity to Harris is equally as thorny as the
question of structural error. Although the state readily
concedes that the immunity agreement was improper,
it contends that the defendant is not entitled to relief
under the plain error doctrine because the defendant
cannot establish that he was harmed by the agreement
in light of the fact that Harris’ testimony did not incul-
pate the defendant. Specifically, the state argues that
Harris’ testimony did not harm the defendant because
‘‘Harris did not testify that the defendant shot him or
Cedeno,’’ but instead ‘‘testified that he did not know
who shot him because he had been intoxicated during
the events and so did not remember them.’’ Thus, in
the state’s view, the error did not cause grievous conse-
quences to the defendant resulting in manifest injustice
to him.
   We first note that the state and the defendant disagree
about which party bears the burden of persuasion with
respect to the question of harm. Citing State v. Fagan,
supra, 280 Conn. 87, and State v. Johnson, 178 Conn.
App. 490, 496, 179 A.3d 780 (2017), cert. denied, 328
Conn. 905, 178 A.3d 390 (2018), the state contends that,
pursuant to the plain error doctrine, the defendant
always maintains the burden of establishing that he
suffered a manifest injustice because of the error. The
defendant asserts that the unlawful immunity
agreement violated his constitutional rights and thus
the state bears the burden of establishing that the error
was harmless beyond a reasonable doubt. According
to the defendant, he is entitled to a new trial ‘‘ ‘if there
is any likelihood’ ’’ that Harris’ testimony could have
affected the verdict. In support of this contention, the
defendant relies on cases in which reviewing courts
have imposed this high burden on the state because of
a prosecutor’s knowing use of perjured testimony in
obtaining the conviction.13 See, e.g., Adams v. Commis-
sioner of Correction, 309 Conn. 359, 371–73, 71 A.3d
512 (2013).
  In addition to the difficulty of deciding which party
bears the burden of persuasion on the question of harm;
see footnote 13 of this opinion; we note that the issue
of whether the defendant was in fact harmed by Harris’
testimony is also a difficult one. Because Harris did
not identify the defendant as the shooter at trial, his
testimony, even if perjurious, should not have been
used by the jury as evidence that the defendant was
the shooter. It is well established that disbelief of a
witness is not the equivalent of proof. State v. Alfonso,
195 Conn. 624, 634, 490 A.2d 75 (1985) (‘‘[w]hile it is
true that it is within the province of the jury to accept
or reject a [witness’] testimony, a jury in rejecting such
testimony cannot conclude that the opposite is true’’
[internal quotation marks omitted]). Thus, even if the
jury found incredible Harris’ testimony that he did not
know who shot him, a conclusion that Harris was lying
is not substantive evidence that the defendant was
the shooter.14
  On the other hand, if the state had been unsuccessful
in forcing Harris to take the witness stand, it would
never have had the opportunity to impeach him with
his prior inconsistent statement to his mother, in which
he identified the defendant as the shooter. Although
this statement was admitted by the court only to assess
the credibility of his testimony at trial that he did not
know the identity of the shooter, the state, during clos-
ing argument, argued to the jury that it should treat his
statement to his mother as substantive evidence that
the defendant was the shooter. In other words, the
state’s improper promise of immunity served as the
mechanism to force Harris to testify, which ultimately
presented the state an opportunity to place before the
jury, albeit improperly, Harris’ statement that the defen-
dant was the shooter.15
   We do not know the state’s precise motive in promis-
ing Harris such broad and unlawful immunity. It is con-
ceivable that the state believed that if it could force
Harris to testify, he simply would ‘‘change his tune’’
and identify the defendant as the person who shot him
and Cedeno. It is also possible that the state was deter-
mined to force Harris to take the witness stand in the
belief that he would testify, consistently with his prior
statement to the police, that he could not identify the
shooter or that he could not remember who shot him.
This testimony would then permit the state to impeach
Harris with his prior inconsistent statement to his
mother that the defendant had shot him. Finally, the
state simply may have wanted to call Harris to paint
him as an obstructionist (as the state argued in closing
argument) so that the jury (1) would not be left to
speculate as to why the state had failed to call him—
an obvious eyewitness to, and victim of, the shooting—
at trial, or (2) would not infer that, as a missing witness,
his testimony would have been unfavorable to the state.
Regardless of the state’s motive, however, forcing Har-
ris onto the witness stand was important enough to the
state’s case against the defendant that the state made
considerable efforts to immunize Harris in exchange
for his testimony, which it presumably deemed ‘‘neces-
sary to the public interest . . . .’’ General Statutes § 54-
47a. It is incongruous for the state now to minimize the
import of Harris’ testimony in order to argue that the
defendant was not harmed by it.
   Again, as with the question of structural error, we
find it unnecessary to resolve the difficult and close
question of prejudice because we conclude that it is
appropriate to exercise our supervisory powers over
the administration of justice and to remand the case for
a new trial. See State v. Rose, supra, 305 Conn. 606–607.
                            IV
   It is well settled that ‘‘[a]ppellate courts possess an
inherent supervisory authority over the administration
of justice.’’ (Internal quotation marks omitted.) State v.
Lockhart, 298 Conn. 537, 576, 4 A.3d 1176 (2010); see
also State v. Rose, supra, 305 Conn. 607. ‘‘Generally,
cases in which we have invoked our supervisory author-
ity for rule making have fallen into two categories. . . .
In the first category are cases wherein we have utilized
our supervisory power to articulate a procedural rule
as a matter of policy, either as [a] holding or dictum, but
without reversing [the underlying judgment] or portions
thereof. . . . In the second category are cases wherein
we have utilized our supervisory powers to articulate
a rule or otherwise take measures necessary to remedy
a perceived injustice with respect to a preserved or
unpreserved claim on appeal. . . . In other words, in
the first category of cases we employ only the rule-
making power of our supervisory authority; in the sec-
ond category we employ our rule-making power and
our power to reverse a judgment. . . .
   ‘‘[T]he salient distinction between these two catego-
ries of cases is that in one category we afford a remedy
and in the other we do not. . . . In the second category
of cases, where we exercise both powers under our
supervisory authority, the party must establish that the
invocation of our supervisory authority is truly neces-
sary because [o]ur supervisory powers are not a last
bastion of hope for every untenable appeal. . . . In
almost all cases, [c]onstitutional, statutory and proce-
dural limitations are generally adequate to protect the
rights of the [appellant] and the integrity of the judicial
system. . . . [O]nly in the rare circumstance [in which]
these traditional protections are inadequate to ensure
the fair and just administration of the courts will we
exercise our supervisory authority to reverse a judg-
ment. . . . In such a circumstance, the issue at hand,
while not rising to the level of a constitutional violation,
is nonetheless of [the] utmost seriousness, not only
for the integrity of a particular trial but also for the
perceived fairness of the judicial system as a whole.’’
(Citations omitted; emphasis altered; internal quotation
marks omitted.) In re Daniel N., 323 Conn. 640, 646–48,
150 A.3d 657 (2016).
  Furthermore, ‘‘[a]n appeals court may . . . raise the
question of whether to use its supervisory powers sua
sponte,’’ and ‘‘concerns regarding unfair surprise and
inadequate argumentation can be alleviated by an order
requiring the parties to file supplemental briefs.’’ State
v. Elson, 311 Conn. 726, 766, 91 A.3d 862 (2014).
   Although ‘‘we normally exercise this power with
regard to the conduct of judicial actors’’; State v. Lock-
hart, supra, 298 Conn. 576; and often have invoked our
supervisory authority to mandate ‘‘rules intended to
guide the lower courts in the administration of justice in
all aspects of the criminal process’’; (internal quotation
marks omitted) State v. Rose, supra, 305 Conn. 607; we
have rejected any arbitrary and categorical limitations
on our use of our supervisory authority. Id. We have
also invoked this power to reverse criminal convictions
tainted by significant prosecutorial impropriety, partic-
ularly in instances when ‘‘the prosecutor deliberately
engages in conduct that he or she knows, or ought to
know, is improper.’’ (Internal quotation marks omitted.)
State v. Thompson, 266 Conn. 440, 485, 832 A.2d 626
(2003), quoting State v. Reynolds, 264 Conn. 1, 165, 836
A.2d 224 (2003), cert. denied, 541 U.S. 908, 124 S. Ct.
1614, 158 L. Ed. 2d 254 (2004). In such cases, our stan-
dards for invoking our supervisory powers ‘‘are flexible
and are to be determined in the interests of justice.’’
(Internal quotation marks omitted.) State v. Payne, 260
Conn. 446, 451, 797 A.2d 1088 (2002). Moreover, reversal
of the conviction does not necessarily serve the purpose
of remedying any particular harm to the defendant in
the case before the court, but ensures that the improper
behavior is not repeated in the future. Id.; State v. Rose,
supra, 611–12.
   Rose is a direct example of the use of supervisory
authority to order a new trial even in the absence of a
showing that the defendant was harmed by the error
or that the error was structural in nature. In Rose, our
Supreme Court granted the state’s petition for certifica-
tion to appeal from this court’s decision to reverse a
criminal conviction in which the trial court had com-
pelled the defendant to appear for trial in identifiable
prison clothing. Certification initially was granted as
to the following questions: ‘‘Did the Appellate Court
properly determine that harmless error analysis does
not apply where the trial court has compelled the defen-
dant to appear before a jury in identifiable prison garb?
If not, was the defendant’s appearance before the jury in
identifiable prison garb harmless beyond a reasonable
doubt?’’ State v. Rose, 290 Conn. 920, 966 A.2d 238
(2009).
   After hearing argument, the court asked the parties
to file supplemental briefs addressing ‘‘[w]hether this
court should affirm the judgment of the Appellate Court
on the [alternative] ground that reversal of the defen-
dant’s conviction is warranted in the exercise of this
court’s inherent supervisory authority over the adminis-
tration of justice.’’ (Internal quotation marks omitted.)
State v. Rose, supra, 305 Conn. 604–605. The state
argued that, if the court exercised its supervisory
authority, it should do so only to issue a prospective
rule and that it should reinstate the defendant’s convic-
tion. Id., 605.
   The Supreme Court, however, elected to exercise its
supervisory authority to reverse the defendant’s convic-
tion and order a new trial, and declined to reach the
issue of whether the defendant had suffered any prejudi-
cial harm. The court stated: ‘‘Because we decide this
case on the basis of our supervisory authority, we need
not resolve the issue of whether a trial court’s constitu-
tionally erroneous decision to compel a defendant to
stand trial before a jury in identifiable prison clothing
is susceptible to harmless error analysis, as the state
claims, or instead amounts to structural error, as the
defendant contends and as the Appellate Court appar-
ently concluded.’’ Id., 606. Similar to the present case,
the court chose to use its supervisory authority to order
a new trial while avoiding the need to determine
whether the error that occurred resulted in harm to the
particular defendant. ‘‘Supervisory powers are exer-
cised to direct trial courts to adopt judicial procedures
that will address matters that are of utmost seriousness,
not only for the integrity of a particular trial but also
for the perceived fairness of the judicial system as
a whole.’’ (Emphasis added; internal quotation marks
omitted.) Id., 607.16
   In the present case, we conclude that it is appropriate
to exercise our supervisory powers over the administra-
tion of justice and to remand this case for a new trial
for several reasons. First, the improper immunity
agreement directly implicates the perception of the
integrity of our justice system. The improper immunity
agreement, which plainly violates our public policy,
gave Harris a license to commit perjury. Historically,
perjury has been characterized as a crime against the
due administration of justice. In fact, § 53a-156 (a),
which criminalizes perjury, is codified at part XI of
chapter 952 in our Penal Code, which is titled: ‘‘Bribery,
Offenses Against the Administration of Justice and
Other Related Offenses.’’ As one legal scholar has writ-
ten: ‘‘In time perjury developed into a [crime] . . .
including everything which has a tendency to injuri-
ously affect the administration of justice by the intro-
duction of falsehood and fraud. . . . [T]he gist of the
offense is the abuse of public justice, and not the injury
to an individual. It does not matter whether the false
oath was believed or disbelieved, or whether it caused
any injury to the person against whom it was given.’’
(Emphasis added; footnotes omitted; internal quotation
marks omitted.) H. Silving, ‘‘The Oath: I,’’ 68 Yale L.J.
1329, 1388 (1959).
   Second, as discussed previously, the existence of the
sanction for perjury plays a critical role in the truth
seeking process and helps to secure the defendant’s
right to confront the witnesses against him. Maryland
v. Craig, supra, 497 U.S. 845–46; Cologne v. Westfarms
Associates, supra, 197 Conn. 153. It is difficult to imag-
ine an error that strikes more directly at the truth seek-
ing process that is at the core of our judicial system
than an agreement, implicitly endorsed by the court,
that permits a witness to testify with a license to lie.
  Third, the reversal of the conviction will help to
ensure that such an unlawful promise will not be made
by prosecutors in the future. In this case, there can
be no doubt that the prosecutor knew that such an
immunity agreement was prohibited by § 54-47a
because the statute is cited in the immunity agreement
that was formally filed with the trial court.17 That knowl-
edge, by itself, was insufficient to deter the state from
promising Harris a form of immunity plainly prohibited
by the statute. The decision to offer such an unlawful
promise was not made in the heat of battle, like a brief
improper remark during closing argument, but was
reached as part of an extensive negotiation between
the state and Harris’ attorney that occurred over parts
of at least two days.
   Fourth, the exercise of our supervisory authority is
also necessary to send a clear message to our trial
courts that they have an affirmative obligation to inter-
cede in circumstances where it appears that the state
has offered a witness a license to lie during the trial.
Indeed, the trial court here realized that the agreement
violated public policy and believed that the witness was
committing perjury but did nothing to prevent it.
   Finally, it is important to remember that the ability
to grant immunity to a witness is a power that belongs
only to the state and is not shared by the defendant. The
defendant cannot compel witnesses who have concerns
about exposing themselves to criminal liability to tes-
tify, even if the defendant believes that their testimony
may be exculpatory to him. Thus, it is important that
courts confine the state’s use of this significant prosecu-
torial power to appropriate instances that do not further
and unfairly disadvantage a defendant.
   The state objects to this court exercising its supervi-
sory authority to reverse the defendant’s conviction for
several reasons. The state contends that it is ‘‘unclear’’
whether the Appellate Court even has the authority to
exercise supervisory powers over the administration of
justice. The state also argues that this court should not
exercise this power sua sponte because the defendant,
in essence, through his inaction, waived any challenge
to the improper immunity agreement. Finally, the state
asserts that the balancing of all of the interests in this
case militates against the use of our supervisory pow-
ers. We disagree with each of these assertions.
  First, this court disagrees with the state that the
Appellate Court lacks supervisory power over the
administration of justice. Our Supreme Court, in refer-
ring to the supervisory power over the administration of
justice, has repeatedly stated that ‘‘[a]ppellate courts’’
possess that power, not just our Supreme Court itself.
See, e.g., State v. Elson, supra, 311 Conn. 768; State v.
Lockhart, supra, 298 Conn. 576. More significantly, this
court has exercised such powers in the past. See State
v. Santiago, 143 Conn. App. 26, 48–51, 66 A.3d 520
(2013) (exercising supervisory authority to reverse con-
viction).18 Although our review of briefs filed by the
state in recent appeals reveals that the state repeatedly
has taken the position that this court should not exer-
cise its supervisory powers when requested to do so
for prudential reasons in a variety of contexts; see, e.g.,
State v. Dijmarescu, 182 Conn. App. 135, 158, 189 A.3d
111, cert. denied, 329 Conn. 912, 186 A.3d 707 (2018);
State v. Castillo, 165 Conn. App. 703, 729, 140 A.3d 301,
aff’d, 329 Conn. 311, 186 A.3d 672 (2018); State v. Fuller,
158 Conn. App. 378, 391, 119 A.3d 589 (2015); our
research has not revealed any case in which our author-
ity to do so has been challenged. We also reject the
state’s argument that our Supreme Court’s recent deci-
sion in State v. Castillo, 329 Conn. 311, 334–35, 335
n.11, 186 A.3d 672 (2018), has raised doubt about this
court’s supervisory powers. In Castillo, the Supreme
Court was never asked to address the existence or
scope of the Appellate Court’s supervisory authority,
and any language employed by the court in a footnote
explaining why it had reformulated the third certified
question in that case is simply taken out of context.19
See id., 335 n.11.
   Second, we are not persuaded by the state’s assertion
that it is improper to exercise our supervisory powers
sua sponte because the defendant waived any challenge
to the illegal immunity agreement by remaining silent
during the colloquy among the court, the state, and
Harris’ attorney. Although the trial judge remarked dur-
ing this initial colloquy that in his forty-two and one-
half years of experience in the criminal justice system,
he had ‘‘never heard of anybody getting that
agreement,’’ the defendant simply failed to object to
Harris’ testimony. We are not convinced, however, that
the defendant’s failure to challenge the propriety of
the immunity agreement was due to a conscious trial
strategy that amounts to a tactical waiver. Nothing in
the record before us supports such a conclusion.
Although, as indicated, defense counsel was present
for the discussions about Harris’ immunity agreement
with the state, and voiced no objection to the agreement
despite the court’s skeptical response, we would have
to resort to impermissible speculation to determine that
defense counsel’s inaction was the result of tactical
calculation rather than inadvertence. Indeed, the defen-
dant had no way to know with certainty that Harris’
testimony would be favorable to him. Although the
defendant may have hoped that Harris would not impli-
cate him in the shooting and would disavow or explain
away the recorded statement to his mother, it was also
possible that, with the broad grant of immunity, Harris
might feel free to implicate the defendant as the shooter.
Furthermore, although the defendant cross-examined
Harris about his inability to identify anyone on the sur-
veillance videotape and relied to some degree on Harris’
testimony during his closing argument, defense counsel
did not go to such lengths to exploit Harris’ testimony
as to suggest a tactical waiver.
   The state, moreover, seems to confound the issue of
implied waiver with a mere failure to object. Ordinarily,
some affirmative action on the part of a defendant is
needed before an appellate court will conclude that a
defendant waived his right to seek appellate review.
For example, by voluntarily and knowingly entering a
guilty plea, a defendant waives his right to raise any
nonjurisdictional claims of error. See, e.g., Savage v.
Commissioner of Correction, 122 Conn. App. 800, 802–
803, 998 A.2d 1247 (2010). The court did not ask the
defendant for input as to the propriety of the agreement,
and the defendant took no affirmative position on the
agreement that could be construed as an express or
implied waiver of his right to challenge it. Except in the
limited circumstances of challenges to jury instructions;
see State v. Kitchens, 299 Conn. 447, 469–70, 10 A.3d
942 (2011); we have not treated a defendant’s inaction
or failure to object to constitute an implied waiver that
precludes the opportunity for appellate review. Indeed,
even in that context, the Supreme Court has indicated
that a defendant still may be entitled to relief on an
unpreserved claim of instructional error pursuant to
the plain error doctrine. State v. McClain, 324 Conn.
802, 808, 155 A.3d 209 (2016).
  Accordingly, we reject the state’s contention that the
defendant’s inaction at trial regarding the unlawful
immunity agreement prevents us from exercising our
supervisory power to remedy such an egregious error
on appeal.
   Finally, we are mindful, of course, as the state notes,
that ‘‘our supervisory authority is not a form of free-
floating justice, untethered to legal principle.’’ (Internal
quotation marks omitted.) State v. Pouncey, 241 Conn.
802, 813, 699 A.2d 901 (1997). Our Supreme Court has
cautioned that, before we exercise our supervisory
powers to reverse a criminal conviction, we must con-
sider and balance all interests involved, including ‘‘the
extent of prejudice to the defendant; the emotional
trauma to the victims or others likely to result from
reliving their experiences at a new trial; the practical
problems of memory loss and unavailability of wit-
nesses after much time has elapsed; and the availability
of other sanctions for such misconduct.’’ (Internal quo-
tation marks omitted.) Id. Having considered these and
other factors raised by the state, we are unconvinced
that, on balance, they require us not to exercise our
supervisory authority under the present circumstances.
   First, as we already discussed in detail in part III
of this opinion, there is a strong argument that the
defendant was unfairly prejudiced by the illegal grant
of immunity to Harris. The state’s improper immuniza-
tion of Harris served as the mechanism to force Harris
to testify, which allowed the state to introduce to the
jury Harris’ prior statement identifying the defendant
as the shooter. The impact on the defendant was then
compounded by the state’s improper use of the state-
ment as substantive evidence during closing arguments.
   Second, the potential that a new trial would result
in significant ‘‘emotional trauma to the victims,’’ as
claimed by the state, seems unlikely. Certainly, both
Harris and Cedeno suffered serious injuries in this case.
Retrial of this case, however, will not involve the view-
ing of graphic and disturbing crime scene or autopsy
photographs as one might expect in a more serious
homicide case. Nor will a retrial require anyone to
describe details of a highly personal nature, as in cases
involving a sexual assault. It also does not involve a
particularly sensitive victim such as a child. Further,
Harris and Cedeno’s claimed lack of memory of the
events and their purported reluctance to aid authorities
in bringing their assailant to justice undermines any
assertion that a retrial would result in any grave emo-
tional retraumatization to them.
  Third, although practical problems like memory loss
and the unavailability of witnesses can arise any time
there is a new trial, such risks are not of particular
concern in the present case. The assaults at issue
occurred in 2013, not in the distant past. This case
does not turn on the testimony of eyewitnesses whose
memories are likely to have faded with the passage of
time. Neither Cedeno nor Harris was able to provide
useful details as to the night they were shot. Harris, in
fact, claimed that he was unable to remember any of
the events of that night due to intoxication. Such an
utter lack of recollection is not likely to worsen over
time. Additionally, although it certainly is possible that
a witness might be unavailable for a retrial, there is
nothing in the record to suggest that any witness has
died or left the jurisdiction of the state.
   Finally, as we have discussed in part I of this opinion,
the state’s impropriety in immunizing Harris for future
perjury, which the trial court expressly recognized but
failed to prevent, violated public policy and undermines
confidence in our judicial system. Although we recog-
nize that reversal of a conviction is a remedy that should
be invoked sparingly, we do not believe another viable
solution exists here. The state has not made us aware
of the availability of any other sanction, short of rever-
sal, that will ensure that the egregious error that
occurred in this case will not be repeated in the future.
  The judgment is reversed and the case is remanded
for a new trial.
      In this opinion SHELDON, J., concurred.
  1
     Although we ordinarily would not reverse a conviction on the basis of
an unpreserved claim of error that was not raised by the parties on appeal,
we have the discretionary authority to address, sua sponte, instances of
error that are cognizable from the record and result in manifest injustice
or constitutional error, provided that we give the parties an opportunity to be
heard by way of supplemental briefing. See Practice Book § 60-5; Blumberg
Associates Worldwide, Inc. v. Brown & Brown of Connecticut, Inc., 311
Conn. 123, 161–62, 162 n.33, 84 A.3d 840 (2014). The parties here were
provided with an opportunity to address fully both the claim of error and
the appropriate remedy. The state has not argued that this court abused its
discretion by raising the claim sua sponte or that it has been unfairly preju-
diced by this procedure, except if we were to reverse the defendant’s convic-
tion pursuant to our supervisory authority over the administration of justice.
Cf. State v. Connor, 321 Conn. 350, 374, 138 A.3d 265 (2016). We will address
that claim of prejudice in this opinion. See part IV of this opinion.
   2
     See Miranda v. Arizona, 384 U.S. 436, 478–79, 86 S. Ct. 1602, 16 L. Ed.
2d 694 (1966).
   3
     The fabricated statement provided, in relevant part: ‘‘My best friend [the
defendant] shot me while he was defending us from another guy who was
trying to rob us. He had a gun too. I do not know the other guy who had
the gun but he was a Spanish guy. I heard his name was ‘Boobie’. My best
friend name is Kevan Simmons, but everybody knows him as ‘Low’. Low
and I were chilling on Bedford Street when the dude tried to rob us for our
money. We all started fighting on the stairs and the Spanish guy pulled out
a gun. Low and I had found the gun Low had earlier that day.
   ‘‘Low normally doesn’t carry a gun, but like I said he found the gun that
day. So when the Spanish guy walked up on us he said ‘‘give me all your
money’’. We told him we didn’t have any money and Low managed to grab
him and we started fighting.
   ‘‘I grabbed him too and that’s when we pulled out a gun. Low stepped
back and pulled out the gun we found and started shooting. Low hit me by
accident and the Spanish guy got hit too. Low is a good guy and doesn’t
carry guns. He was protecting us and I respect him for that. The police
should arrest the Spanish guy for trying to rob us.
   ‘‘The detectives showed me some photos and I picked out a guy I know
as Low. I have known Low for years. Low came back to the scene after he
shot me because that’s my boy and he cares about me. Low went to the
hospital too. I am not mad at Low for shooting me by accident. I respect
him for protecting me because that Spanish guy could have killed us. We
didn’t even have no money like that for him to be robbing us.
   ‘‘That is all I have to say about me being shot. Kevan Simmons is Low
and they call ‘Deep’.’’
   4
     The state filed with the court a document, signed by Gail P. Hardy, the
Hartford state’s attorney, partially memorializing the grant of immunity.
It states: ‘‘Under [§ 54-47a], the Hartford State’s Attorney’s Office grants
immunity from prosecution for George Harris for any alleged conduct
directly or indirectly related to Hartford Case # 13-9934 and State v. Kev[a]n
Simmons, Docket No.: HHD-CR13-0666536-T. The immunity shall be transac-
tional immunity for the events on March 28, 2013, and use immunity—direct
and derivative—for all other proceedings.’’
   This memorialization does not appear to include the state’s promise to
immunize Harris from prosecution for any perjury he might commit while
testifying at the defendant’s trial.
   5
     Although the jury was not shown the video at that time, the video was
later shown to the jury and admitted into evidence as a full exhibit.
   6
     See footnote 17 of this opinion.
   7
     General Statutes § 53a-156 (a) provides in relevant part: ‘‘A person is
guilty of perjury if, in any official proceeding, such person intentionally,
under oath . . . makes a false statement, swears, affirms or testifies falsely,
to a material statement which such person does not believe to be true.’’
   8
     The record is unclear as to whether the court made the predicated
findings required by the statute in order to permit a grant of immunity to
the witness. Certainly, the remarks made by the court implicitly sanctioned
the state’s arrangement with Harris, and Harris testified in accordance with
his agreement with the state.
   9
     It is unclear, on the basis of the record presented, whether Harris testified
pursuant to an order issued directly under § 54-47a because the immunity
agreement filed by the state with the court does not appear to be the
byproduct of an application filed by the state with the court seeking an
order compelling Harris to testify. Moreover, the court did not explicitly
issue an order in the public interest or otherwise require Harris to testify
pursuant to a particular grant of immunity. It would strain credulity, however,
to imagine that the prosecutor could directly offer a witness immunity for
perjury committed while providing immunized testimony if such a grant of
immunity would be prohibited if ordered by the court pursuant to the
procedures of § 54-47a.
   10
      The Supreme Court of Delaware afforded an unlawful immunity
agreement harmless error review in Worthy v. State, 120 A.3d 581, 586–87
(Del. 2015). In Worthy, the court concluded that the state failed to demon-
strate that the error was harmless beyond a reasonable doubt. Id., 587.
   11
      One example given by the court in Gonzalez-Lopez of structural error
that may not necessarily result in demonstrable harm to a particular defen-
dant but nevertheless warrants reversal are cases in which a defendant
improperly is denied his right to self-representation, ‘‘a right that when
exercised usually increases the likelihood of a trial outcome unfavorable
to the defendant . . . .’’ (Internal quotation marks omitted.) United States
v. Gonzalez-Lopez, supra, 548 U.S. 149 n.4.
   12
      Even if the error in this case implicated only a statutory as opposed to
a constitutional right of the defendant, the deprivation of that statutory right
may also be so significant as to constitute structural error. For example,
our Supreme Court has suggested, without explicitly deciding, that a court’s
noncompliance with a statute mandating that the jury be instructed regarding
the defendant’s constitutional right not to testify is structural error and not
subject to harmless error analysis. State v. Sinclair, 197 Conn. 574, 584–86,
500 A.2d 539 (1985); see also State v. Ruocco, 322 Conn. 796, 805, 144 A.3d
354 (2016).
   13
      Although we ultimately need not decide which party bears the burden
of persuasion on this issue, we note that our Supreme Court has suggested
that, although a party seeking to prevail pursuant to the plain error doctrine
typically is obligated to demonstrate that it suffered a ‘‘manifest injustice,’’
the state may still bear the burden of establishing harm if the underlying
error was constitutional in nature. See State v. Moore, 293 Conn. 781, 823,
981 A.2d 1030 (2009), cert. denied, 560 U.S. 954, 130 S. Ct. 3386, 177 L. Ed.
2d 306 (2010). In Moore, the court concluded that the defendant could not
prevail under the plain error doctrine in circumstances in which the trial
court failed to caution the jury to scrutinize carefully the testimony of an
alleged accomplice. Id., 827. In reaching that conclusion, the court noted
that because an instructional error relating to general principles of witness
credibility ‘‘ ‘is not constitutional in nature’ ’’ the burden rested on the defen-
dant rather than the state to demonstrate harm. Id., 824. This language
strongly suggests that if the underlying error had been constitutional in
nature, then the state would bear its usual burden of demonstrating harm
beyond a reasonable doubt.
   Adhering to this typical allocation of burden in the context of deciding
claims arising under the plain error doctrine makes perfect sense and is not,
as the state contends, ‘‘doctrinally incongruent.’’ With respect to unpreserved
errors arising during a criminal trial, the defendant may seek appellate
review and to prevail either under the plain error doctrine or pursuant to
State v. Golding, 213 Conn. 233, 239–40, 567 A.2d 823 (1989), as modified
by In re Yasiel R., 317 Conn. 773, 781, 120 A.3d 1188 (2015). If the claim is
not of a constitutional nature, the defendant will typically be confined to
the plain error doctrine because a party may prevail under Golding only if
the claim is of a constitutional nature. If the defendant establishes a violation
of a constitutional right, then the state is obligated to demonstrate, pursuant
to the fourth prong of Golding, ‘‘harmlessness of the . . . constitutional
violation beyond a reasonable doubt.’’ Id., 240. Thus, most claims of plain
error historically have not implicated a defendant’s constitutional rights
because of the availability of Golding review, and thus a defendant would
properly bear the burden of establishing harm.
   14
      We also recognize that, in assessing whether the error harmed the
defendant, his written statement to the police was admitted into evidence.
In that statement, the defendant allegedly admitted to the police that he
shot Cedeno and Harris, but did so in self-defense. Importantly, however,
the defendant substantially challenged the credibility of Detective Early,
who obtained the defendant’s statement, because of Early’s creation of the
fabricated written statement of Harris. Moreover, the defendant has raised
the additional claim on appeal that the state violated his rights by not
disclosing, prior to trial, information regarding an internal affairs investiga-
tion of Early that would have yielded further evidence to undermine his credi-
bility.
   15
      None of the other witnesses at trial testified that the defendant shot
Harris and Cedeno.
   16
      Likewise, in State v. Payne, supra, 260 Conn. 446, our Supreme Court
reversed a criminal conviction, holding that a new trial was warranted
because of the prosecutor’s repeated and deliberate misconduct during
closing argument, which included appealing to the jury’s emotions and
improperly vouching for a prosecution witness’ credibility. Although the
court concluded that the prosecutor’s misconduct did not violate the defen-
dant’s right to a fair trial in that particular case, it nonetheless exercised
its supervisory authority ‘‘in order to protect the rights of defendants and
to maintain standards among prosecutors throughout the judicial system
rather than to redress the unfairness of a particular trial’’ and ‘‘to send a
strong message that such conduct will not be tolerated.’’ (Internal quotation
marks omitted.) Id., 452. Although the court in Payne identified a pattern
of misconduct by the prosecutor spanning several cases, and stated that
this pattern of misconduct was a significant factor in its decision to exercise
its supervisory authority, it did not expressly hold that such a pattern of
misconduct was a necessary requirement to the exercise of our supervisory
powers. Moreover, any attempt to read such a requirement into its holding
would thwart the standard it set forth, namely, that our supervisory powers
must be flexible and that their application must be determined by the interest
of justice. Id., 451; see also State v. Rose, supra, 305 Conn. 607.
   17
      It is true, as the state contends, that there does not appear to be a
record of repeated instances of impropriety by this prosecutor in other cases.
Nevertheless, we reject the state’s assertion that we should not exercise
our supervisory powers because the impropriety in this case was not deliber-
ate and the prosecutor in this case has not engaged in repeated instances
of prosecutorial impropriety in other cases.
   First, we are not exercising our supervisory powers in this case merely
because of prosecutorial impropriety. Indeed, a large measure of our deci-
sion to do so is a result of the trial court’s unwillingness to prohibit the
arrangement entered into between the state and Harris. The trial court
certainly appeared to recognize that the immunity agreement was improper
when it stated on the record that the agreement was ‘‘probably against the
public interest, but I didn’t step in.’’ Moreover, in our view, the prosecutor
knew, or certainly should have known, that the agreement was unlawful.
The need to obtain immunity for Harris was discussed during trial, and, in
fact, a continuance was granted in order to allow the state to work out an
immunity agreement. The prosecutor filed an immunity agreement with the
court, which included a citation to § 54-47a, which he presumably had read.
A review of that statute’s plain language should have alerted the prosecutor
that the scope of the immunity deal he offered to Harris at trial exceeded
the authority provided for under the statute.
   18
      The state in Santiago did not challenge our authority to exercise supervi-
sory powers over the administration of justice. It also did not seek certifica-
tion to appeal to our Supreme Court to challenge our decision on that basis.
   19
      Footnote 11 of the majority opinion in State v. Castillo, supra, 329 Conn.
311, states: ‘‘A narrow and literal interpretation of the certified issue as
limited to the question of whether the Appellate Court properly declined
to exercise any authority it may have to issue the requested prophylactic
rule would yield the bizarre result that if this court agreed with the defendant,
it would remand the case to the Appellate Court with direction to exercise
such supervisory authority. That narrow reading would constitute an
improper abdication of this court’s duty and authority over the administra-
tion of justice.’’ Id., 335 n.11.
