   STATE OF CONNECTICUT v. THOMAS STEELE
                 (AC 37956)
                      Alvord, Sheldon and Norcott, Js.

                                  Syllabus

Convicted of the crimes of robbery in the first degree, conspiracy to commit
    robbery in the first degree and conspiracy to commit larceny in the
    third degree in connection with his conduct in robbing a bank, the
    defendant appealed to this court. He challenged the sufficiency of the
    evidence to support his robbery conviction and also claimed, inter alia,
    that the trial court improperly admitted lay testimony from a detective,
    D, concerning historic cell site analysis, a certain process that utilizes
    cell phone records and cell site locations to identify the location of cell
    phones at a particular time. Specifically, he claimed that the court should
    have qualified D as an expert witness before permitting him to testify
    about how he used the defendant’s cell phone records to determine his
    whereabouts before, during and after the bank robbery. Held:
1. There was sufficient evidence presented at trial to support the defendant’s
    conviction of robbery in the first degree as a principal: the jury reason-
    ably could have credited the testimony of M, the defendant’s friend,
    that the defendant had told M that he robbed a bank but discredited
    M’s testimony that she understood him to be joking, and the state
    presented a variety of direct and circumstantial evidence that created
    a connection between the physical attributes and possessions of the
    robber and the defendant, including, inter alia, surveillance footage
    of the robbery, eyewitness testimony describing what the robber was
    wearing, which matched other surveillance footage that depicted the
    defendant wearing similar clothing, and evidence of the defendant’s
    purchase of a BB gun like the one used in the robbery; moreover,
    although the evidence was not inconsistent with the defendant being
    the getaway driver instead of the robber, a reasonable view of the
    evidence supported a finding that the defendant acted as a principal
    during the robbery, which was the only theory of liability the state
    pursued at trial and on which the court instructed the jury.
2. The trial court abused its discretion by not requiring D to be qualified as
    an expert witness before allowing him to testify regarding historic cell
    site analysis: although that analysis is not extremely difficult to under-
    stand, the analytical process involved therein is beyond the ken of
    the average juror, as call detail records can be used to determine the
    approximate location of a cell phone at the time of a particular communi-
    cation by determining the geographical coverage area of the cell sector
    used to facilitate that communication, and that process of determining
    the coverage area requires scientific and technical knowledge, which
    would require a trial court, prior to admitting such testimony, to conduct
    a hearing to ensure that the testimony was based on a reliable scientific
    methodology, and contrary to the state’s claim, D did not merely read
    from a document that was already in evidence, he explained how cell
    phones and cell sites operate and, thus, broached the realm of expert
    testimony; nevertheless, the admission of D’s testimony was harmless
    beyond a reasonable doubt, as the state presented substantial evidence
    of the defendant’s involvement in the bank robbery, including his admis-
    sion to M that he robbed a bank, and D’s testimony was largely cumula-
    tive of other direct and circumstantial evidence establishing the
    defendant’s locations before, during and after the robbery.
3. The defendant’s conviction of and sentences on the charges of conspiracy
    to commit robbery and conspiracy to commit larceny, having arisen out
    of a single agreement to rob the bank, violated his right against double
    jeopardy; accordingly, his conviction of both conspiracy charges could
    not stand.
           Argued April 18—officially released August 29, 2017

                             Procedural History

   Substitute information charging the defendant with
of the crimes of robbery in the first degree, conspiracy
to commit robbery in the first degree and conspiracy
to commit larceny in the third degree, brought to the
Superior Court in the judicial district of Ansonia-Milford
and tried to the jury before Markle, J.; verdict and
judgment of guilty, from which the defendant appealed
to this court. Reversed in part; judgment directed.
  James B. Streeto, senior assistant public defender,
with whom, on the brief, was Maria V. Morse, certified
legal intern, for the appellant (defendant).
  Rocco A. Chiarenza, assistant state’s attorney, with
whom, on the brief, were Kevin D. Lawlor, state’s attor-
ney, and Amy L. Bepko, assistant state’s attorney, for
the appellee (state).
                           Opinion

   ALVORD, J. The defendant, Thomas Steele, appeals
from the judgment of conviction, rendered after a jury
trial, of robbery in the first degree in violation of General
Statutes § 53a-134 (a) (4), conspiracy to commit robbery
in the first degree in violation of General Statutes
§§ 53a-48 (a) and 53a-134 (a) (4), and conspiracy to
commit larceny in the third degree in violation of Gen-
eral Statutes §§ 53a-48 (a) and 53a-124 (a) (2). On
appeal, the defendant claims that (1) there was insuffi-
cient evidence presented at trial to convict him of rob-
bery in the first degree; (2) the trial court abused its
discretion and violated his rights under the confronta-
tion clause of the sixth and fourteenth amendments
to the United States constitution when it permitted a
detective to testify about historic cell site analysis with-
out being qualified as an expert witness; and (3) his
cumulative conviction and sentences for conspiracy to
commit robbery and conspiracy to commit larceny vio-
late the double jeopardy clause of the fifth and four-
teenth amendments to the United States constitution.
We agree with the defendant that his cumulative convic-
tions and sentences for conspiracy to commit robbery
and conspiracy to commit larceny violate the double
jeopardy, but we reject the defendant’s other claims.
Accordingly, we reverse the judgment in part and affirm
the judgment in part.
   On the basis of the evidence presented at trial, the
jury reasonably could have found the following facts.
In the early morning hours of Saturday, February 16,
2013, the defendant checked into a Comfort Inn in Nau-
gatuck and paid the required $100 deposit in cash. Later
that morning, at approximately 9:30 a.m., the defendant
purchased a Beretta Airsoft BB gun (facsimile firearm),
which looked like a Beretta style handgun, at a Walmart
in Derby. Thereafter, the defendant returned to the
Comfort Inn to check out. Caitlin Mitchell and an
unidentified black male accompanied the defendant
during the checkout process. When he was informed
that he had to wait for housekeeping to check his room
before his cash deposit would be refunded, the defen-
dant became irate, insisting that he had to be some-
where and threatening to call the police if his deposit
was not returned. Eventually, the hotel manager calmed
the defendant down while the checkout process was
completed. At approximately 11:30 a.m., after the hotel
manager was informed that the defendant’s room was
in order, she placed the defendant’s deposit on the
counter beside her while she printed a receipt for the
defendant. The defendant reached over the counter,
grabbed the money, and left with Mitchell and the
unidentified black male before the hotel manager could
complete the checkout process. After exiting the hotel,
all three individuals entered the defendant’s green
Cadillac Deville and left.1
   At 11:54 a.m., the defendant ran into the Webster
Bank in Seymour while wearing dark blue jeans, a black
ski mask, and grey gloves. He pointed his facsimile
firearm at Tara Weiss, the assistant bank manager, and
ordered everybody ‘‘[to] get to the fucking floor.’’ After
the bank employees and customers complied with his
order, the defendant jumped onto and then over the
teller counter and aimed his facsimile firearm at Dan-
ielle George, a bank teller. He ordered her to open her
cash drawer and place the money in the bag he pro-
vided. As George complied with his order, another teller
behind the counter began to move. The defendant aimed
his facsimile firearm at the other teller and told her
‘‘not to be a hero . . . .’’ The defendant returned his
attention to George. George continued to put money in
the defendant’s bag and managed to place a dye pack
in the bag as well.2 When George finished, the defendant
took the bag and exited the bank.
   On June 4, 2013, the defendant was arrested for his
role in the bank robbery. In the operative information,
the defendant was charged with robbery in the first
degree, conspiracy to commit robbery in the first
degree, and conspiracy to commit larceny in the third
degree. After a trial, a jury found the defendant guilty
of all counts. The defendant was sentenced to a total
effective sentence of ten years of incarceration followed
by four years of special parole.3 This appeal followed.
Additional facts will be set forth as necessary.
                            I
  We begin with the defendant’s claim that there was
insufficient evidence presented at trial to convict him
of robbery in the first degree as a principal, which was
the only theory of liability the state pursued at trial
and on which the court instructed the jury. The state
responds that, when viewing the evidence in the light
most favorable to sustaining the verdict, there was suffi-
cient circumstantial evidence for a jury to reasonably
conclude that the defendant acted as a principal during
the robbery. We agree with the state.
  The following additional facts are relevant to this
claim. As the robber exited the bank, he ordered Weiss
to count to 100. Weiss initially complied and began
counting. Once the robber left the bank, however, she
jumped up, ran to the doors, and locked them. Weiss
then returned to her station, pressed the bank’s panic
alarm, and called 911. After speaking with a 911 opera-
tor, Weiss reported the robbery to Webster Bank’s emer-
gency hotline and to the branch manager, Jason
Rodriguez, who was in New York. Rodriguez immedi-
ately began driving back to Connecticut from New York.
State and federal law enforcement personnel arrived at
the bank shortly thereafter and obtained, inter alia,
surveillance footage of the robbery. Surveillance foot-
age from inside the bank revealed that the robber wore
dark blue jeans, grey gloves, and a black ski mask.
Surveillance footage from outside the bank revealed
that a green vehicle, which was similar in appearance
to the defendant’s Cadillac, entered the bank parking
lot shortly before the robbery and picked up an individ-
ual on Spruce Street shortly after the robbery.4
  After leaving the bank, the robber and his compan-
ion(s) initially drove north on Route 8, stopping in Bea-
con Falls to dispose of the discharged dye pack and
the cash that was burned when the dye pack discharged.
Shortly thereafter, members of law enforcement, with
the assistance of a pedestrian, recovered the dye pack
and some of the burned and stained cash from an area
near the Beacon Falls Police Department.
   Later that day, at approximately 2 p.m., the defendant
and an unidentified black male were traveling north-
bound on Route 8 when they stopped to dispose of a
facsimile firearm by throwing it onto the embankment
along the side of the highway. Unbeknownst to the
defendant and his companion, Rodriguez, who was also
traveling northbound on Route 8 on his way to the bank,
observed this conduct. When he neared the defendant’s
Cadillac, he immediately noticed that it was being
driven erratically. In response, he slowed down and
watched as the Cadillac swerved into the breakdown
lane, where he saw the driver throw an object over the
roof of the Cadillac and onto the embankment. Because
of the suspicious nature of this conduct and his knowl-
edge of the recent robbery at his bank branch, Rodri-
guez used his cell phone to record his observations,
including the vehicle’s make, color, and license plate
number and a brief physical description of the men
in the driver’s and front passenger’s seats.5 He then
reported the incident to the police. Shortly thereafter,
officers recovered a black Beretta style facsimile fire-
arm from the Route 8 embankment near the Bridgeport-
Trumbull line. Notably, the tip of the recovered facsim-
ile firearm was covered with black electrical tape.
  Shortly after the incident along Route 8, the defen-
dant purchased professional strength Goo Off and rub-
ber cleaning gloves with cash at the Home Depot in
Derby. He then proceeded to the Post Motor Inn in
Milford where he rented a cabin in his own name and
paid for it in cash. The following morning, February 17,
2013, the defendant checked into the Super 8 Motel in
Milford with Mitchell, paying for the room with cash.
  That evening, a patrol officer reported that she had
located the Cadillac involved in the Webster Bank rob-
bery in the Super 8 Motel parking lot. Shortly thereafter,
officers investigating the bank robbery arrived. After
speaking to the employees at the front desk of the motel
and reviewing its surveillance footage, the officers
determined that the defendant was associated with the
Cadillac and that he was staying in room 206. After
about fifteen minutes of knocking on the defendant’s
door, the defendant came to the window of his room
but refused to open the door. He denied ever being in
Seymour or knowing anything about the Cadillac in the
parking lot, claiming that a friend had dropped him off
at the motel. When the detectives asked him whether
he knew anything about a bank robbery, he stated that
he did not, but added that ‘‘if [the officers] had enough
information on him, [they] would be arresting him right
now.’’ Members of the Milford Police Department then
detained the defendant and Mitchell in the lobby of the
Super 8 Motel. When special agent Lisa C. McNamara
of the Federal Bureau of Investigation arrived, she
attempted to talk to Mitchell, but the defendant kept
yelling at her: ‘‘Don’t talk to them, you don’t have to
talk to them, your parents have to be present, you don’t
have to talk to them.’’ As a result, McNamara brought
Mitchell outside of the lobby and they sat in an
unmarked police cruiser so that they could talk without
the defendant hearing.
   Officers subsequently seized several items from the
Super 8 Motel. From the defendant and Mitchell’s
vacated room, they seized a hotel room key for the
room that the defendant had rented at the Comfort Inn.
From the hotel staff, they obtained surveillance footage,
which showed the defendant arriving at the motel in
his Cadillac and checking into his room. Notably, during
the course of check-in, the defendant could be seen
removing several folded bundles of cash from his pants
pockets and using that cash to pay for his room. Because
the defendant paid in cash, officers further seized from
the Super 8 Motel seventy dollars that was stained with
red dye, which they believed that the defendant used
to pay for the room. Subsequent forensic tests con-
firmed the presence of chemicals used in bank dye
packs on the stained cash.
  In addition to retrieving several items from the Super
8 Motel staff, officers seized and searched the defen-
dant’s Cadillac. In the Cadillac, officers found five pairs
of grey latex gloves, receipts from Walmart and Home
Depot, and a roll of black electrical tape. The latex
gloves that were recovered from the Cadillac’s glove
box were similar in appearance to the ones worn by
the individual who had robbed the Webster Bank. The
Walmart receipt helped the officers obtain surveillance
footage from Walmart, which confirmed that on the
morning of the robbery the defendant, who was wearing
dark blue jeans, arrived at Walmart in his Cadillac and
purchased a facsimile firearm of the same make and
model as the one recovered from the embankment along
Route 8. Subsequent forensic tests revealed that the
electrical tape found in the defendant’s Cadillac was
indistinguishable from the electrical tape found on the
facsimile firearm recovered from the embankment
along Route 8.
  Because the defendant appeared to lead a transient
lifestyle in which he frequently moved from motel to
motel, officers checked with hotels and motels in the
area to determine whether he had stayed in them after
the robbery. When they arrived at the Post Motor Inn,
they learned that the defendant had checked into a
cabin at 2:51 p.m. on the day of the robbery. On his
registration card, the defendant had listed two people
in his party and had noted his vehicle’s make and license
plate number. The officers noticed that the sink in the
defendant’s cabin was tinted red and that the snow
behind the cabin was stained red. They took samples
of the stained snow. In the tree line near the cabin, the
officers found a garbage bag, which contained, inter
alia, rubber gloves similar to those the defendant had
purchased at Home Depot, towels with red stains on
them, and an empty bottle of soap. A Post Motor Inn
employee also gave them a black ski mask that he had
found in the snowbank approximately thirty feet from
the defendant’s cabin. Subsequent forensic tests con-
firmed that the gloves and towels retrieved from the
garbage bag and the seized samples of stained snow
contained traces of the chemicals used in bank dye
packs.
   Finally, at trial, Mitchell testified that on the weekend
of the robbery she had seen the defendant in possession
of ‘‘a substantial amount of money’’ and cleaning ‘‘red
stuff’’ off his Cadillac. Mitchell also testified that the
defendant had told her that he ‘‘robbed a bank . . . .’’
Mitchell maintained that when the defendant stated that
he robbed a bank, he did so ‘‘jokingly’’ and, as a result,
she did not take him seriously. She admitted, however,
that the defendant was her friend and that ‘‘I don’t want
to be here with this,’’ i.e., ‘‘to testify against someone
that was close to me . . . .’’ After the parties rested
and presented closing arguments, the court instructed
the jury. With respect to the charge of robbery in the
first degree, the court instructed the jury only on princi-
pal liability.
   ‘‘The standard of review we apply to a claim of insuffi-
cient evidence is well established. In reviewing the suffi-
ciency of the evidence to support a criminal conviction
we apply a two-part test. First, we construe the evidence
in the light most favorable to sustaining the verdict.
Second, we determine whether upon the facts so con-
strued and the inferences reasonably drawn therefrom
the [finder of fact] reasonably could have concluded
that the cumulative force of the evidence established
guilt beyond a reasonable doubt. . . .
   ‘‘We note that the jury must find every element proven
beyond a reasonable doubt in order to find the defen-
dant guilty of the charged offense, [but] each of the
basic and inferred facts underlying those conclusions
need not be proved beyond a reasonable doubt. . . .
If it is reasonable and logical for the jury to conclude
that a basic fact or an inferred fact is true, the jury is
permitted to consider the fact proven and may consider
it in combination with other proven facts in determining
whether the cumulative effect of all the evidence proves
the defendant guilty of all the elements of the crime
charged beyond a reasonable doubt. . . .
   ‘‘Moreover, it does not diminish the probative force
of the evidence that it consists, in whole or in part, of
evidence that is circumstantial rather than direct. . . .
It is not one fact, but the cumulative impact of a multi-
tude of facts which establishes guilt in a case involving
substantial circumstantial evidence. . . . In evaluating
evidence, the [finder] of fact is not required to accept
as dispositive those inferences that are consistent with
the defendant’s innocence. . . . The [finder of fact]
may draw whatever inferences from the evidence or
facts established by the evidence it deems to be reason-
able and logical. . . .
  ‘‘Finally, [a]s we have often noted, proof beyond a
reasonable doubt does not mean proof beyond all possi-
ble doubt . . . nor does proof beyond a reasonable
doubt require acceptance of every hypothesis of inno-
cence posed by the defendant that, had it been found
credible by the [finder of fact], would have resulted in
an acquittal. . . . On appeal, we do not ask whether
there is a reasonable view of the evidence that would
support a reasonable hypothesis of innocence. We ask,
instead, whether there is a reasonable view of the evi-
dence that supports the [finder of fact’s] verdict of
guilty.’’ (Internal quotation marks omitted.) State v.
Crespo, 317 Conn. 1, 16–17, 115 A.3d 447 (2015).
   We conclude that there was sufficient evidence pre-
sented at trial to support the defendant’s conviction of
robbery in the first degree. First, Mitchell testified that
the defendant told her that he ‘‘robbed a bank . . . .’’
On the basis of this testimony, the jury could have
concluded that when the defendant said that he ‘‘robbed
a bank,’’ he meant that he personally had robbed a bank.
The defendant, relying on the corpus delicti doctrine,
argues that Mitchell’s testimony cannot support his con-
viction because his purported confession is uncorrobo-
rated. The purpose of the corpus delicti doctrine,
however, is to protect against convictions for offenses
that have not in fact occurred. State v. Farnum, 275
Conn. 26, 33–34, 878 A.2d 1095 (2005). The corpus delicti
doctrine has no bearing on the present case because it
is undisputed that the Webster Bank in Seymour was
robbed on February 16, 2013; indeed, it is undisputed
on appeal that the defendant was one of the individuals
who conspired to rob the bank.
  The defendant further suggests that Mitchell’s testi-
mony cannot support his conviction because Mitchell
testified that she did not take the defendant seriously
when he said that he ‘‘robbed a bank . . . .’’ A jury
may properly decide, however, ‘‘what—all, none, or
some—of a witness’ testimony to accept or reject.’’
(Internal quotation marks omitted.) State v. Victor C.,
145 Conn. App. 54, 61, 75 A.3d 48, cert. denied, 310
Conn. 933, 78 A.3d 859 (2013). The jury in this case
very well could have credited Mitchell’s testimony that
the defendant told her that he robbed a bank but dis-
credited her testimony that she understood him to be
joking. Mitchell admitted that the defendant was her
friend and that she did not want ‘‘to testify against
someone that was close to [her].’’ The jury reasonably
could have concluded, therefore, that Mitchell charac-
terized the defendant’s statement as a joke because of
her desire to protect him.
   The defendant’s robbery conviction, however, is not
supported solely by Mitchell’s testimony. At trial, the
state presented a variety of direct and circumstantial
evidence creating a connection between the physical
attributes and possessions of the robber and the defen-
dant. The jury had before it surveillance footage of the
robbery. When determining if the defendant was the
robber, the jurors could have compared surveillance
footage of the robber with other surveillance footage
of the defendant and their own observations of the
defendant in court to determine if there was a physical
resemblance between the robber and the defendant.
Additionally, the bank surveillance footage and eyewit-
ness testimony established that the robber possessed
a black firearm and was wearing dark blue jeans, grey
gloves, and a black ski mask. Walmart surveillance foot-
age depicted the defendant wearing dark blue jeans on
the morning of the robbery. The receipt and surveillance
footage from Walmart further established that while at
Walmart the defendant personally purchased a black
facsimile firearm, which was the same make and model
as the facsimile firearm an individual driving a Cadillac
disposed of later that afternoon by throwing it onto an
embankment alongside of Route 8. Five pairs of grey
latex gloves similar to those worn by the robber were
recovered from the Cadillac’s glove compartment, and
a black ski mask similar to the one worn by the robber
was recovered from a snowbank approximately thirty
feet from the defendant’s cabin at the Post Motor Inn.
   Although it can be argued that this evidence is not
inconsistent with the defendant being the getaway
driver instead of the robber, ‘‘[i]n reviewing a suffi-
ciency of the evidence claim . . . we do not ask
whether there is a reasonable view of the evidence that
would support a reasonable hypothesis of innocence.
We ask, instead, whether there is a reasonable view of
the evidence that supports the jury’s verdict of guilty.’’
(Internal quotation marks omitted.) State v. Silva, 285
Conn. 447, 459, 939 A.2d 581 (2008). Mindful that in
determining the sufficiency of the evidence we consider
its cumulative effect and construe the evidence in the
light most favorable to sustaining the verdict, we deter-
mine that there was sufficient evidence presented at
trial to support the defendant’s conviction of robbery
in the first degree.
                            II
   The defendant next claims that the court improperly
admitted lay testimony concerning historic cell site
analysis.6 Specifically, the defendant argues that the
court should have qualified Detective Steven Ditria as
an expert witness before permitting him to testify about
how he used the defendant’s cell phone records to deter-
mine his whereabouts before, during, and after the bank
robbery. The defendant further contends that this evi-
dentiary error obstructed his rights under the confronta-
tion clause because Ditria’s lack of training, education,
or experience with cell phones, cellular networks, and
cell site analysis prevented him from being meaningfully
cross-examined on this evidence.7 The defendant seeks
review of this unpreserved constitutional claim pursu-
ant to State v. Golding, 213 Conn. 233, 567 A.2d 823
(1989); see also In re Yasiel R., 317 Conn. 773, 781, 120
A.3d 1188 (2015) (modifying third condition of Gold-
ing).8 The state responds that Ditria merely read from
a document that was already in evidence, i.e., the defen-
dant’s cell phone records and instructions from the
cellular carrier on interpreting those records, and, thus,
his testimony was factual, not opinion.9 Alternatively,
the state argues that any error in the admission of this
testimony was harmless beyond a reasonable doubt.
We agree with the defendant that the court abused its
discretion by not requiring Ditria to be qualified as an
expert witness, but we agree with the state that this
error was harmless beyond a reasonable doubt. Accord-
ingly, the defendant’s constitutional claim fails under
the fourth prong of Golding. See State v. Dixon, 318
Conn. 495, 511, 122 A.3d 542 (2015).
                            A
   To understand the significance of the trial court’s
decision to permit a lay witness to testify about historic
cell site analysis, it is first necessary to understand the
manner in which cell phones and cellular networks
operate. Although the trial court did not have the benefit
of such information when it made its evidentiary ruling,
we share the view of our sister courts that such informa-
tion is essential to understanding how historic cell site
data is generated and what inferences that data sup-
ports concerning the locations of a cell phone, and by
inference its user, during a communication. E.g., State
v. Payne, 440 Md. 680, 690–98, 104 A.3d 142 (2014);
Collins v. State, 172 So. 3d 724, 740–41 (Miss. 2015);
State v. Patton, 419 S.W.3d 125, 130–31 (Mo. App. 2013);
State v. Johnson, 797 S.E.2d 557, 561–62 (W. Va. 2017);
see, e.g., Commonwealth v. Augustine, 467 Mass. 230,
236–39, 4 N.E.3d 846 (2014) (reviewing cell phone tech-
nology prior to determining whether police were
required to obtain search warrant to obtain information
from defendant’s cell phone service provider); State v.
Earls, 214 N.J. 564, 574–78, 70 A.3d 630 (2013) (same).
We will rely in this overview on information and materi-
als relied on by our sister courts when discussing cellu-
lar network technology or cell site analysis.
   Cell phones are essentially sophisticated two way
radios that use cellular networks comprised of cell
sites10 and radio frequency (RF) antennae to communi-
cate with one another. State v. Payne, supra, 440 Md.
692; J. Beck et al., ‘‘The Use of Global Positioning (GPS)
and Cell Tower Evidence to Establish a Person’s Loca-
tion—Part II,’’ 49 Crim. L. Bull. Art. 8, 2 (2013). A cell
site is the fixed location that provides cellular coverage
using RF antennae, a base station, and other network
equipment. J. Beck et al., supra, 3. The geographical
coverage area of a cell site is called a cell sector.11 See
United States v. Bohannon, 824 F.3d 242, 256 (2d Cir.
2016), cert. denied,        U.S.    , 137 S. Ct. 628, 196 L.
Ed. 2d 517 (2017). The shape and size of a cell sector
is variable and depends on several external and internal
factors. External factors include the surrounding envi-
ronment and geography, e.g., the location of buildings,
vehicles, vegetation, and land masses, which might pre-
vent the RF signal from propagating in a uniform and
uninterrupted manner. State v. Payne, supra, 693–94;
A. Blank, ‘‘The Limitations and Admissibility of Using
Historical Cellular Site Data to Track the Location of
a Cellular Phone,’’ 18 Rich. J.L. & Tech. 3, 6–7 (2011);
see generally T. Singal, Wireless Communications 35–
65, 100 (2011) (discussing propagation patterns of radio
frequency signals). Internal factors include the techni-
cal characteristics of the cell site and the RF antennae.
State v. Payne, supra, 693; A. Blank, supra, 4–6.
   There are four types of cell sites generally used by
cellular companies: macrocells, microcells, picocells,
and femtocells. M. Harris, Unison, How Cell Towers
Work 2–3 (2011), available at www.unisonsite.com/pdf
/resource-center/How%20Towers%20Work.pdf (last vis-
ited August 23, 2017) (hereinafter M. Harris, How Cell
Towers Work); Geolocation Privacy and Surveillance
(GPS) Act: Hearing on H.R. 2168 before the Subcommit-
tee on Crime, Terrorism, Homeland Security and Inves-
tigations of the House Committee on the Judiciary,
113th Cong. 45, 54–55 (2013) (written testimony of Mat-
thew Blaze, associate professor of computer and infor-
mation science, University of Pennsylvania), available
at      https://judiciary.house.gov/wp-content/uploads/
2016/02/113-34-80542.pdf (last visited August 23, 2017)
(hereinafter Blaze testimony); see also United States
v. Davis, 785 F.3d 498, 542 (11th Cir.), cert. denied,
     U.S.    , 136 S. Ct. 479, 193 L. Ed. 2d 349 (2015).
Macrocells are prototypical ‘‘cell towers,’’ although they
can be attached to a structure, and can cover an area
often miles in diameter or more in rural areas where
there is less signal interference. M. Harris, How Cell
Towers Work, supra, 3; Blaze testimony, supra, 54; see
also Sprint Spectrum L.P. v. Zoning Board of Adjust-
ment, 21 F. Supp. 3d 381, 391 (D.N.J. 2014), aff’d, 606
Fed. Appx. 669 (3d Cir. 2015). Microcells typically are
used in urban or suburban settings to cover an area
that is less than one mile in diameter. M. Harris, How
Cell Towers Work, supra, 3. A picocell is a small base
station that acts like an extension cord, extending the
macrocell’s or microcell’s signal through high traffic or
obstructed areas and covering an area of less than 250
yards in diameter. Id.; M. Harris, Unison, Think Small:
Micro, Pico and Femto Cell Sites 2 (2011), available at
http://www.unisonsite.com/pdf/resource-center/Think-
%20Small%20Unison-whitepaper-7D.pdf (last visited
August 23, 2017) (hereinafter M. Harris, Think Small).
Finally, a femtocell is like a booster pack; it uses a
broadband Internet connection to ‘‘backhaul’’ mobile
calls and data traffic into a wireless carrier’s existing
cellular network. M. Harris, Think Small, supra, 2; see
also EON Corp IP Holdings LLC v. Cisco Systems, Inc.,
36 F. Supp. 3d 912, 923 (N.D. Cal. 2014), aff’d, 595 Fed.
Appx. 991 (Fed. Cir. 2015). The coverage range of these
devices is similar to that of a cordless phone base. M.
Harris, How Cell Towers Work, supra, 3; M. Harris,
Think Small, supra, 2; Blaze testimony, supra, 55; see
also United States v. Davis, supra, 503–504 n.7.
   Each of the four types of cell sites contains, inter
alia, a base station and at least one RF antenna. M.
Harris, How Cell Towers Work, supra, 2, 6. An RF
antenna can be omnidirectional or multidirectional. An
omnidirectional antenna is intended to service the
entire, 360 degree area around a cell site. T. Singal,
supra, p. 100; M. Harris, How Cell Towers Work, supra,
5–6; see also Ruckus Wireless, Inc. v. Netgear, Inc.,
Docket No. C 08-2310 PJH, 2013 WL 6627737, *1, *4
(N.D. Cal. December 16, 2013). The idealized cell sector
of a cell site with an omnidirectional antenna is a hexa-
gon with the cell site at the center.12 E.g., T. Singal,
supra, pp. 99–100; M. Harris, How Cell Towers Work,
supra, 5. In contrast, directional antennae are intended
to service only small portions of the area around a cell
site. For example, a cellular carrier might use three
directional antennae with beam widths set at 120
degrees in order to achieve 360 degrees of coverage
around a cell site. Collins v. State, supra, 172 So. 3d
740; J. Beck et al., supra, 49 Crim. L. Bull. Art. 8, 3; see
also T. O’Connor, ‘‘Provider Side Cell Phone Forensics,’’
3 Small Scale Digital Device Forensics J. 1 (2009) (dis-
cussing and depicting typical cell site and antenna con-
figurations), available at http://ctfdatapro.com/pdf/
celltower.pdf (last visited August 23, 2017). With this
configuration, the idealized cell sector is a wedge, with
a center angle of 120 degrees, emanating out from the
cell site. E.g., State v. Payne, supra, 440 Md. 724 (appen-
dix C); T. O’Malley, ‘‘Using Historical Cell Site Analysis
Evidence in Criminal Trials,’’ 59 U.S. Atty. Bull. 16, 19
(2011), available at https://www.hsdl.org/?view&did
=701377 (last visited August 23, 2017). The directional
orientation of a directional antenna is called its ‘‘azi-
muth.’’13 T. O’Connor, supra, 1; United States v. Mack,
Docket No. 3:13-cr-00054 (MPS), 2014 WL 6474329, *2
(D. Conn. November 19, 2014).
   Every seven seconds, regardless of whether it is being
used, a cell phone will ‘‘register’’ with in-range cell
sites.14 J. Beck et al., supra, 49 Crim. L. Bull. Art. 8, 3; A.
Blank, supra, 18 Rich. J.L. & Tech. 5. When an individual
places a call or sends a message, the cell phone commu-
nicates with the base station at the cell site with which
it has the strongest, best quality signal. J. Beck et al.,
supra, 3–4; A. Blank, supra, 5; see also United States
v. Mack, supra, 2014 WL 6474329, *3. Through various
processes, the base station of that cell site helps the
transmitting cell phone connect to the receiving cell
phone, which will also use the cell site with the strong-
est, best quality signal to receive the call or message.
See generally T. O’Malley, supra, 59 U.S. Atty. Bull.
20–21. Importantly, the cell site in closest proximity to
these cell phones might not be the one producing the
strongest, best quality signal for them. J. Beck et al.,
supra, 3; see A. Blank, supra, 5. The characteristics of
the cell site, the RF antenna, and the cell phone as well
as a variety of environmental and geographic factors
influence which cell site has the strongest, best quality
signal for a cell phone.15
   In addition, it is possible that during a communication
the cell site being used by either the transmitting or
the receiving cell phone will cease to be the one with
the strongest, best quality signal for that cell phone. In
this circumstance, a ‘‘handoff,’’ or ‘‘handover,’’ will
occur to ensure that the communication is not dis-
rupted. A. Blank, supra, 18 Rich. J.L. & Tech. 5–6. Hand-
offs are broadly classified as being ‘‘hard’’ or ‘‘soft’’
depending on the cell phone system the cellular carrier
uses. A hard, or ‘‘break before make,’’ handoff involves
a definite decision by the cell phone to break its connec-
tion with its current cell site before, or as, it makes a
connection with a new cell site. D. Wong & T. Lim, ‘‘Soft
Handoffs in CDMA Mobile Systems,’’ IEEE Personal
Communications, 6 (1997), available at http://wireless.-
stanford.edu/papers/DWongsoftHandoff.pdf (last vis-
ited August 23, 2017); L. Paul, ‘‘Handoff/Handover
Mechanism for Mobility Improvement in Wireless Com-
munication,’’ 13 Glob. J. Res. Engineering Elec. & Elecs.
Engineering 6, 7 (2013), available at https://globaljour-
nals.org/GJRE Volume13/2-Handoff-Handover-Mecha-
nism.pdf (last visited August 23, 2017).
   Conversely, during a soft, or ‘‘make before break,’’
handoff a cell phone will simultaneously connect to
multiple base stations until it determines which of the
in-range cell sites is producing the strongest, best qual-
ity signal. D. Wong & T. Lim, supra, 6; L. Paul, supra, 8–9.
  Every time a cell phone sends or receives a communi-
cation the base station at the cell site automatically
generates a call detail record. State v. Payne, supra,
440 Md. 695–96 and 696 n.24; In re United States for
Historical Cell Site Data, 724 F.3d 600, 611–12 (5th Cir.
2013); J. Beck et al., supra, 49 Crim. L. Bull. Art. 8, 4. The
purpose of call detail records is to enable the cellular
provider to bill a subscriber accurately for his or her
cell phone usage and to help the carrier understand the
calling patterns of their subscribers. J. Beck et al., supra,
4; see also State v. Payne, supra, 695; In re United
States for Historical Cell Site Data, supra, 611–12. Call
detail records can contain a variety of information
depending on the cellular carrier, but these records
ordinarily include some information about the cell
site(s) used to make or receive the communication.16
State v. Payne, supra, 696; J. Beck et al., supra, 4; T.
O’Malley, supra, 59 U.S. Atty. Bull. 23; Blaze testimony,
supra, 57. The call detail records in the present case
contain information about the cell sites in use when the
cell phone initiated and terminated a communication.
   One form of historic cell site analysis uses the cell
site and antenna information contained in a call detail
record to determine which cell sector a cell phone was
using at the time of a certain communication and,
thereby, the geographical area the cell phone, and by
inference its user, was in at that time. The geographical
coverage area of a specific cell sector can be determined
by conducting a drive test or by estimating the cell
sector.17 Drive testing involves the use of RF mapping
equipment and software to map the actual cell sector
generated by a particular cell site and antenna. E.g., T.
O’Malley, supra, 59 U.S. Atty. Bull. 28; see also id., 29
(depicting cell sector based on drive testing). This
method was developed by cellular carriers to help them
monitor and maintain the quality of their cellular net-
works, but it has also been used by law enforcement
agencies to track suspects and fugitives and by attor-
neys at trial to establish a cell phone’s, and by inference
its user’s, approximate locations at particular dates and
times. See T-Mobile Central, LLC v. Unified Govern-
ment of Wyandotte Country/Kansas City, Kan., 528 F.
Supp. 2d 1128, 1140, 1150–52, 1166–67 (D. Kan. 2007),
aff’d in part, 546 F.3d 1299 (10th Cir. 2008); T. O’Malley,
supra, 28–29.
  Although the precision of drive testing makes it the
preferred method for determining the shape and size
of a cell sector, performing a drive test is not always
possible. United States v. Mack, supra, 2014 WL
6474329, *3. For example, the cell site might have been
removed or its characteristics altered by the cellular
carrier since the crime was committed. E.g., id. (federal
agent testified that drive testing was not possible
because cell site in question was no longer present
at time of his investigation). In this circumstance, the
approximate size and shape of a cell sector can be
determined by drawing a pie-wedge diagram on a map.
Id. The center angle of the pie-wedge corresponds to
the antenna’s beam width setting, e.g., 120 degrees, and
the outward boundary of the pie-wedge will extend 50
to 70 percent of the way into the opposing cell sector.
Id.; United States v. Machado-Erazo, 950 F. Supp. 2d
49, 55–56 (D.D.C. 2013); United States v. Davis, Docket
No. 11-60285-CR, 2013 WL 2156659, *5–6 (S.D. Fla. May
17, 2013); e.g., T. O’Malley, supra, 59 U.S. Atty. Bull. 28
(depicting estimated cell sector superimposed on map).
Critically, the boundaries of an estimated cell sector
are not fixed. Depending on a variety of factors, the
actual cell sector can be smaller or larger than the
estimated cell sector. T. Singal, supra, p. 100; A. Blank,
supra, 18 Rich. J.L. & Tech. 5; see also T. O’Malley,
supra, 28–29 (depicting idealized cell sector and actual
cell sector).
                              B
  Against the foregoing scientific and technical back-
ground, we turn to the defendant’s claims on appeal.
As we previously stated, the threshold issue is whether
the court improperly permitted lay testimony concern-
ing historic cell site analysis. The following additional
facts are relevant to our resolution of this claim. At the
time of the robbery, the defendant owned a cell phone
serviced by Sprint-Nextel (Sprint). During the course
of his investigation, Ditria subpoenaed the defendant’s
subscription information and call detail records from
Sprint, and, at trial, the state entered the materials
Sprint provided into evidence as exhibit 77.
   Exhibit 77 includes, inter alia, the defendant’s call
detail records, instructions on how to interpret those
records, and a list of cell site locations. The call detail
records are in the form of a ten column chart, which,
in relevant part, has columns titled, ‘‘First Cell,’’ and,
‘‘Last Cell.’’ The ‘‘key’’ to the call detail records explains
that ‘‘First Cell’’ and ‘‘Last Cell’’ refer to the specific
cell site and ‘‘sector’’ through which the communication
was initiated and terminated. ‘‘The first digit [of the cell
site identification number] reflects the sector. The last
3-4 digits represent the [cell] site number. . . . For
example, if the number in the [First Cell or Last Cell]
column reads 2083, the cell site is 083 and the sector
is 2.’’ (Emphasis omitted.) A separate, eighteen column
chart provided by Sprint contains a variety of informa-
tion about Sprint’s cell sites, including the address and
azimuth of each cell site. Exhibit 77 does not define
what a ‘‘sector’’ or ‘‘azimuth’’ is.18 Nor does it contain
any general or specific information on cellular net-
works, the geographical coverage areas of Sprint’s cell
sites, or the operation of cell phones and cell sites.
   At trial, Ditria explained that learning the defendant’s
cell phone number was ‘‘crucial’’ because he ‘‘wanted
to learn the whereabouts of [the defendant] based on
his phone records.’’ Once he knew the defendant’s cell
phone number, Ditria testified, he subpoenaed the
defendant’s cell phone records from Sprint. Ditria iden-
tified the documents provided by Sprint, which were
entered into evidence as exhibit 77 without objection.
Ditria explained that although he understood the
‘‘[b]asic incoming and outgoing phone calls’’ when he
received the call detail records, he needed help to
understand the cell site information within them. He
contacted a Sprint representative, whose job it was to
assist law enforcement, ‘‘to learn about the communica-
tion of the cell phone and the cell tower . . . .’’
   When Ditria began to explain his current understand-
ing of ‘‘the significance of a cell tower,’’ defense counsel
objected on foundational grounds, stating: ‘‘I think he
is giving opinion testimony here regarding, I think that’s
where we’re going here.’’ The court asked the prosecu-
tor for a response, to which she replied: ‘‘What he under-
stands about cell phone records now after being
educated.’’ The court overruled the objection. There-
after, the following colloquy occurred:
  ‘‘[The Prosecutor]: Okay. You were explaining what
a cell phone tower is for.
  ‘‘[Ditria]: In order for a phone call to be made, incom-
ing or outgoing, you have to have a cell tower, and it
dedicates the subscriber information, checking if it’s a
legitimate phone number, and with that carrier.
  ‘‘[The Prosecutor]: Can you make a phone call with-
out a cell tower?
  ‘‘[Ditria]: Absolutely not.
  ‘‘[The Prosecutor]: And did you also learn how close
a cell phone has to be to a tower in order to receive
information from it?
  ‘‘[Ditria]: Yes.
  ‘‘[The Prosecutor]: And how far away can a phone
be to bounce off the tower?
  ‘‘[Ditria]: Anywhere from zero to thirty miles.
  ‘‘[The Prosecutor]: A big radius?
  ‘‘[Ditria]: Right.
   ‘‘[The Prosecutor]: So, cell phone—at thirty miles or
right next to the tower?
  ‘‘[Ditria]: Correct.
  ‘‘[The Prosecutor]: That’s the tower that’s it’s going
to bounce off of?
  ‘‘[Ditria]: Correct.
  ‘‘[The Prosecutor]: And so, did he also teach you how
to read these?
  ‘‘[Ditria]: Yes.
  ‘‘[The Prosecutor]: Okay. And so, I’m going to pick
a random page, page number two of thirty. How can
you determine from this page what cell tower you are
looking for? What column are we looking at?’’
  Defense counsel objected, explaining: ‘‘I think we’re
getting into the realm of expert testimony here, and I
don’t think that the officer has been qualified as an
expert. What we’re trying to do here is to educate the
jury, and I think that’s wholly in the purview of an
expert.’’ The prosecutor replied: ‘‘The officer has indi-
cated that he did not know how to read the records,
but now he does know how to read the records and
has demonstrated to the jury that he has the information
in front of him.’’ The court overruled the defendant’s
objection, stating that it found that proper foundation
had been laid for the admission of exhibit 77 into evi-
dence and that ‘‘[i]t’s part of his investigation, he learned
how to interpret the data. I’ll allow him now to testify
from the document entered into evidence.
   Direct examination of Ditria continued. The prosecu-
tor asked Ditria, ‘‘[h]ow is this information helpful to
your understanding of the case,’’ and Ditria explained
that it ‘‘[b]asically, pinned down the whereabouts of
[the defendant] before, during, and after the robbery
of Webster Bank.’’ Thereafter, Ditria explained in detail
how the defendant’s call detail records helped him to
confirm the defendant’s presence near eight areas of
interest: Walmart, the Comfort Inn, the Webster Bank,
Beacon Falls, Bridgeport, Home Depot, the Post Motor
Inn, and the Super 8 Motel. In particular, Ditria testified
as to when the defendant or the bank robbery suspect
was believed to be in the area of interest, when the
communication in question was made, the address of
one of the cell sites used by the defendant’s cell phone,19
and the distance from that cell site to the area of inter-
est.20 After reviewing these details, the prosecutor asked
Ditria: ‘‘So, after learning the proximity of the cell tower
locations to the places that you believe that [the defen-
dant] was at, what does that do for your investigation?’’
Ditria responded: ‘‘It gives us a better understanding
about the whereabouts of [the defendant] during those
dates and times.’’
  On cross-examination, defense counsel attempted to
explore Ditria’s understanding of cell site analysis
through the following colloquy:
  ‘‘[Defense Counsel]: And now, Sprint only operates
a digital cell phone system; isn’t that right?
  ‘‘[Ditria]: I’m not sure.
  ‘‘[Defense Counsel]: All right. Do you know if they
operate an analog system?
  ‘‘[Ditria]: I’m not sure.
  ‘‘[Defense Counsel]: And the phones that we use now
are all digital, right?
  ‘‘[Ditria]: (Indicating yes.)
  ‘‘[Defense Counsel]: And I think you were testifying
that the cell phones connect to a particular tower, right?
  ‘‘[Ditria]: Yes.
  ‘‘[Defense Counsel]: And didn’t they tell you that they
actually connect to more than one tower simultane-
ously; isn’t that right?
  ‘‘[Ditria]: They did not say that.
  ‘‘[Defense Counsel]: They didn’t say that?
  ‘‘[Ditria]: No. . . .
   ‘‘[Defense Counsel]: Do you know that the cell phone
is always looking for the strongest signal?
  ‘‘[Ditria]: I don’t know if it’s looking for the strong-
est, no.
   ‘‘[Defense Counsel]: Now, do you know that on a
digital cell phone, they can connect to multiple cell
sites; did you know that?
  ‘‘[Ditria]: I did not know that.
  ‘‘[Defense Counsel]: They didn’t tell you that?
  ‘‘[Ditria]: (Indicating no.)
  ‘‘[Defense Counsel]: And the representative at Sprint,
did he tell you that there’s things that can get in the
way of a signal from a cell tower?
  ‘‘[Ditria]: He did not say that.
  ‘‘[Defense Counsel]: Things like leaves, weather; did
he say that?
  ‘‘[Ditria]: He did not say that.
  ‘‘[Defense Counsel]: That the wind could impact the
coverage of a cell site; did he say that?
  ‘‘[Ditria]: He did not.
  ‘‘[Defense Counsel]: And that digital cell phones have
this thing called a soft handoff; did he tell you what
that is?
  ‘‘[Ditria]: No.
  ‘‘[Defense Counsel]: Have you ever heard of the
term triangulation?
  ‘‘[Ditria]: I have not.
  ‘‘[Defense Counsel]: They didn’t tell you or explain
that to you over the phone?
  ‘‘[Ditria]: No.’’
   The defendant requested to make a motion outside
the presence of the jury. After the jury was excused, the
defendant moved to strike Ditria’s testimony regarding
‘‘the cell phone coverage’’ because he was not compe-
tent to testify on that topic. The court disagreed,
explaining: ‘‘There was never any offer that he is an
expert, and he did not offer any opinions. He is simply
interpreting or translating the data that was given to
him.’’ The state agreed, adding: ‘‘[I]t just goes to the
weight of his testimony.’’ The court overruled defense
counsel’s objection, but it stated, in response to a ques-
tion from defense counsel, that it was ‘‘perfectly fine’’
for defense counsel to explore the defendant’s educa-
tion, or lack thereof, with respect to cell phones and
cellular networks on cross-examination. Thereafter,
defense counsel continued his cross-examination, dur-
ing which he explored Ditria’s lack of education and
training concerning cell phones and cellular networks.
   After Ditria’s testimony, both parties rested and pre-
sented closing arguments. During her opening argu-
ment, the prosecutor referred to Ditria’s testimony
concerning the location of the defendant’s cell phone,
highlighting in particular the short distance between
cell sites used by the defendant’s cell phone and the
areas of interest. In response, defense counsel during
his closing argument emphasized that Ditria ‘‘didn’t
have any expertise as to how these things actually
work.’’ During her rebuttal argument, the prosecutor
made the following relevant remarks: ‘‘Ditria said that
he had no formal education in cell phone tower mechan-
ics, but he did have the wherewithal to call somebody
who did, right? And we found out that a cell tower is
in a fixed location and that cell phones are mobile,
mobile phones, right? So, if you know where the cell
tower is, and that’s in a fixed location, and a cell phone
is mobile, but you know that there are these other things
that are fixed locations, like Walmart; Walmart is not
mobile, right? Walmart is where it is. Home Depot is
where it is. The Super 8 is not moving without some
significant effort, okay? So, if you have [the defendant]
pinned down in those places, then you could also coor-
dinate the fact that his cell phone is pinging off cell
towers in a fixed location all within a mile. Does Ditria
really need all that technological expertise to explain
it to you, okay?’’
   ‘‘We review a trial court’s decision [regarding the
admission of] expert testimony for an abuse of discre-
tion. . . . If we determine that a court acted improp-
erly with respect to the admissibility of expert
testimony, we will reverse the trial court’s judgment
and grant a new trial only if the impropriety was harmful
to the appealing party.’’ (Internal quotation marks omit-
ted.) State v. Edwards, 325 Conn. 97, 123, 124, 156
A.3d 506 (2017). A lay witness may not provide opinion
testimony ‘‘unless the opinion is rationally based on the
perception of the witness . . . .’’ Conn. Code Evid. § 7-
1. In order for a witness to testify concerning ‘‘scientific,
technical or other specialized knowledge,’’ the witness
must be ‘‘qualified as an expert by knowledge, skill,
experience, training, [or] education . . . .’’ Conn. Code
Evid. § 7-2. ‘‘Expert testimony should be admitted when:
(1) the witness has a special skill or knowledge directly
applicable to a matter in issue, (2) that skill or knowl-
edge is not common to the average person, and (3)
the testimony would be helpful to the court or jury in
considering the issues. . . . [T]o render an expert opin-
ion the witness must be qualified to do so and there must
be a factual basis for the opinion.’’ (Internal quotation
marks omitted.) State v. Williams, 317 Conn. 691, 702,
119 A.3d 1194 (2015).
   Our analysis of the evidentiary issue presented by the
defendant is informed by our Supreme Court’s recent
decision in State v. Edwards, supra, 325 Conn. 97. In
Edwards, the state sought to elicit testimony from
Detective Christopher Morris concerning how he used
the defendant’s call detail records to determine his loca-
tion at certain points in time and to offer into evidence
maps that Morris created showing the estimated cell
sectors of the cell sites in question. Id., 119–22. As part
of the state’s offer of proof, Morris testified as to his
training and experience conducting historic cell site
analysis. Id., 121. ‘‘The trial court then ruled that the
state had met its burden of establishing the reliability
of the proffered evidence and that Morris was qualified
by his expertise to analyze cell phone data provided in
Verizon records.’’ Id., 122.
  On appeal, our Supreme Court agreed with the defen-
dant that ‘‘the trial court improperly admitted testimony
and documentary evidence through Morris without
qualifying him as an expert and conducting a Porter
hearing21 in order to ensure that his testimony was based
on [a] reliable scientific methodology.’’ (Footnote
added.) Id., 133. In reaching this conclusion, the court
observed that it ‘‘has not had the opportunity to address
whether a police officer needed to be qualified as an
expert witness before he could be allowed to testify
regarding cell phone data . . . .’’ Id., 127. Relying on
State v. Payne, supra, 440 Md. 680, the court concluded
that Morris’ testimony concerning historic cell site anal-
ysis constituted expert testimony and, therefore, Morris
should have been qualified as an expert witness. State v.
Edwards, supra, 325 Conn. 128, 133. The court observed
that ‘‘although Morris relied on data he obtained from
Verizon to conduct his analysis [of the defendant’s call
detail records], the process he used to arrive at his
conclusions [concerning the approximate coverage
areas of the cell sites in question] was beyond the ken
of [an] average [person].’’ Id., 128.
   We conclude that Edwards is controlling as to this
issue on appeal.22 Although historic cell site analysis is
not extremely difficult to understand, we agree with
the court in Edwards that this analytical process is
beyond the ken of the average juror. As we discussed
in part II A of this opinion, call detail records can be
used to determine the approximate location of a cell
phone at the time of a particular communication by
determining the geographical coverage area of the cell
sector used to facilitate that communication. This pro-
cess of determining the actual or approximate geo-
graphical coverage area of a cell sector requires
scientific and technical knowledge. Specifically, it
requires an understanding of how cell sites and RF
antennae operate, and knowledge of all of the internal
and external factors that influence the size and shape
of a cell sector. Indeed, in recognition of the scientific
underpinnings of historic cell site analysis, our Supreme
Court in Edwards held that a court must conduct a
Porter hearing prior to admitting testimonial or docu-
mentary evidence of historic cell site analysis. Id., 132–
33. For these reasons, we conclude that the court
abused its discretion by not requiring Ditria to be quali-
fied as an expert witness.
   The state nonetheless urges that ‘‘when Ditria’s testi-
mony is reviewed in relation to the cell phone records
themselves, a document that was admitted as a full
exhibit without objection, it is clear that the substance
of his testimony, i.e., the particular cell tower that the
defendant’s cell phone connected with at particular
times, did not constitute ‘expert’ testimony at all, but
was the equivalent of Ditria merely reading from a docu-
ment that was already in evidence.’’ We disagree; Ditria
did not merely read from exhibit 77. Ditria testified that
in order to make a phone call, a cell phone must use
a cell site. Ditria then explained that in order to use a
cell site, a cell phone must be within thirty miles of it.
Ditria further agreed with the prosecutor that, because
of these principles, if a cell phone is ‘‘at thirty miles or
right next to’’ a cell site, then that is the cell site that
the cell phone is going to use to make or receive a call.
None of this information is contained in Exhibit 77. By
explaining to the jury how cell phones and cellular sites
operate and the geographical coverage area of Sprint’s
cell sites, Ditria broached the realm of expert testimony.
   Having concluded that the court abused its discretion
by not requiring Ditria to be qualified as an expert
witness, we turn to the defendant’s confrontation clause
claim. Because the defendant seeks Golding review of
this unpreserved constitutional claim, we do not need
to determine whether the court’s failure to qualify Ditria
as an expert witness obstructed the defendant’s con-
frontation rights if this error was harmless beyond a
reasonable doubt. See State v. Dixon, supra, 318
Conn. 511.
   ‘‘[W]hether [an improper evidentiary ruling] is harm-
less in a particular case depends upon a number of
factors, such as the importance of the witness’ testi-
mony in the prosecution’s case, whether the testimony
was cumulative, the presence or absence of evidence
corroborating or contradicting the testimony of the wit-
ness on material points, the extent of cross-examination
otherwise permitted, and, of course, the overall strength
of the prosecution’s case. . . . Most importantly, we
must examine the impact of the . . . evidence on the
trier of fact and the result of the trial. . . . [T]he proper
standard for determining whether an erroneous eviden-
tiary ruling is harmless should be whether the jury’s
verdict was substantially swayed by the error.’’ (Internal
quotation marks omitted.) State v. Edwards, supra, 325
Conn. 133; accord State v. Santos, 318 Conn. 412, 425,
121 A.3d 697 (2015). For the purposes of our analysis,
we assume that this evidentiary error was of constitu-
tional magnitude and, therefore, the burden is on the
state to prove that this error was harmless beyond a
reasonable doubt. See State v. Santos, supra, 425.
   We conclude that the admission of Ditria’s testimony
was harmless beyond a reasonable doubt. As we dis-
cussed in part II of this opinion, the state presented
substantial and varied evidence of the defendant’s
involvement in the bank robbery, including the defen-
dant’s admission to Mitchell that he robbed a bank.
Moreover, Ditria’s testimony was largely cumulative
evidence of the defendant’s location before, during, and
after the robbery. Specifically, Ditria’s testimony was
used to corroborate the defendant’s presence near eight
areas of interest: Walmart, the Comfort Inn, the Webster
Bank, Beacon Falls, Bridgeport, Home Depot, the Post
Motor Inn, and the Super 8 Motel. The state established
the defendant’s presence at all of these locations
through other direct and circumstantial evidence. For
example, surveillance footage established the defen-
dant’s presence at Walmart and the Super 8 Motel as
well as the presence of a vehicle similar in appearance
to the defendant’s Cadillac at the Webster Bank during
the robbery. The Walmart and Home Depot receipts
recovered from the defendant’s Cadillac corroborated
the defendant’s presence at those stores. Rodriguez’
testimony and the recovered facsimile firearm, which
was the same make and model as the one the defendant
purchased from Walmart, established the defendant’s
and his Cadillac’s presence on Route 8 near the Bridge-
port-Trumbull line. To establish the defendant’s pres-
ence at various hotels, the state admitted into evidence
registration forms, in the defendant’s own name, for
the Comfort Inn, the Post Motor Inn, and the Super 8
Motel and presented the testimony of employees from
those hotels who confirmed that guests must present
a driver’s license when checking into those establish-
ments. Finally, all of the direct and circumstantial evi-
dence of the defendant’s participation in the robbery
corroborates his presence in Beacon Falls, where the
dye pack associated with George’s cash drawer was
recovered shortly after the robbery.
   As a result, even though we conclude that the court
abused its discretion by not requiring Ditria to be quali-
fied as an expert witness, we also conclude that this
error was harmless beyond a reasonable doubt. There-
fore, the defendant’s constitutional claim fails under
the fourth prong of Golding.
                           III
  The defendant’s final claim is that his cumulative
convictions and sentences for conspiracy to commit
robbery and conspiracy to commit larceny violated his
right against double jeopardy. The defendant seeks
Golding review of this unpreserved constitutional
claim. The defendant’s claim is reviewable under Gold-
ing because the record is adequate to review the alleged
claim of error and the claim is of constitutional magni-
tude alleging the violation of a fundamental right. See
State v. Dixon, supra, 318 Conn. 511. As the state con-
cedes, the defendant is further entitled to reversal of
one of his conspiracy convictions under Golding
because both convictions arose out of a single
agreement to rob the Webster Bank in Seymour. See
State v. Wright, 320 Conn. 781, 829, 135 A.3d 1 (2016)
(‘‘it is a double jeopardy violation to impose cumulative
punishments for conspiracy offenses if they arise from
a single agreement with multiple criminal objectives’’).
   The appropriate remedy for this due process violation
is to reverse the judgment of conviction as to both
counts of conspiracy and to remand the case to the
trial court with direction to vacate the defendant’s con-
viction of conspiracy to commit larceny and to render
judgment on the defendant’s remaining conviction of
conspiracy to commit robbery. See id., 829–30; see also
State v. Lee, 325 Conn. 339, 345, 157 A.3d 651 (2017);
State v. Padua, 273 Conn. 138, 171–73, 869 A.2d 192
(2005). The defendant further requests that we direct
the trial court to resentence him with respect to his
remaining conviction of conspiracy to commit robbery.
Cf. State v. Wright, supra, 320 Conn. 830. We cannot
order the trial court to resentence the defendant, how-
ever, because vacatur of the defendant’s conviction and
sentence for conspiracy to commit larceny will not alter
his total effective sentence. See State v. Johnson, 316
Conn. 34, 42–43, 111 A.3d 447 (2015); see footnote 3 of
this opinion.
   The judgment is reversed only with respect to the
conviction of conspiracy to commit larceny in the third
degree and the case is remanded with direction to
vacate the judgment as to that conviction. The judgment
is affirmed in all other respects.
      In this opinion the other judges concurred.
  1
     At trial, the defendant disputed possessing or operating the Cadillac,
which was registered to and insured by Wardell Eaddy. The state presented
substantial evidence, however, that although Eaddy registered the Cadillac
in his own name as a favor to the defendant, the defendant possessed and
operated the Cadillac at the time of the robbery.
   2
     A ‘‘dye pack’’ is a bank security feature that is made up of a stack of
actual currency with its center removed and a dye pack put in its place.
The dye pack is designed to release red dye, tear gas, and smoke at a
designated period of time after the device has been removed from the bank.
When the dye pack explodes, it becomes very hot and can burn currency
it comes in contact with it. The serial numbers of the devices and the bills
used on the top and bottom of the stack are recorded to pair specific packets
with specific teller stations inside a bank.
   3
     For both his conviction of robbery in the first degree and his conviction
of conspiracy to commit robbery, the defendant was sentenced to ten years
of incarceration followed by four years of special parole. For his conviction
of conspiracy to commit larceny, the defendant was sentenced to five years of
incarceration. The court further ordered that the defendant’s three sentences
were to be served concurrently.
   4
     Raider, a canine trained and certified in tracking humans, tracked a
scent from the front door of the Webster Bank where the robber was last
seen to the corner of Garden Street and Spruce Street where he lost the
trail. Raider’s handler testified that he observed fresh tire tracks in the area
where Raider lost the scent trail.
   5
     Rodriguez testified that the driver, who threw the object, had a thin
mustache and that the passenger, whom he did not get a good look at, was
wearing a hat. In surveillance footage from Walmart and a hotel the defendant
stayed at the day after the robbery, the defendant is seen with a thin black
mustache and a light grey beard.
   6
     Historic cell site analysis involves the use of cell phone records and cell
site locations to determine, within some range of error, a cell phone’s
approximate location at a particular time. United States v. Natal, 849 F.3d
530, 534 (2d Cir. 2017).
   7
     It is unclear whether the defendant also claims that Ditria’s testimony
concerning what he learned from a Sprint representative about how cell
phones and cellular networks operate was improper and constituted a con-
frontation violation under Crawford v. Washington, 541 U.S. 36, 124 S. Ct.
1354, 158 L. Ed. 2d 177 (2004). In the ‘‘legal standard’’ section of his opening
appellate brief, the defendant briefly reviewed the principles of Crawford
and, in one paragraph, argues why ‘‘the ‘interpretations of the data’ offered
through Detective Ditria constituted testimonial hearsay’’ in violation of
Crawford. The defendant did not thereafter advance, in his briefs or at oral
argument before this court, a claim that a Crawford violation occurred.
Indeed, the defendant’s briefs and oral argument focused principally on his
claim that Ditria should have been qualified as an expert witness and that
the court’s failure to do so obstructed his confrontation rights. As a result,
we conclude that, to the extent the defendant alleges a Crawford violation,
this claim is inadequately briefed. See State v. Buhl, 321 Conn. 688, 724,
138 A.3d 868 (2016).
   8
     ‘‘Under Golding, a defendant can prevail on a claim of constitutional
error not preserved at trial only if all of the following conditions are met:
(1) the record is adequate to review the alleged claim of error; (2) the claim
is of constitutional magnitude alleging the violation of a fundamental right;
(3) the alleged constitutional violation . . . exists and . . . deprived the
defendant of a fair trial; and (4) if subject to harmless error analysis, the
state has failed to demonstrate harmlessness of the alleged constitutional
violation beyond a reasonable doubt. In the absence of any one of these
conditions, the defendant’s claim will fail.’’ (Internal quotation marks omit-
ted.) State v. Dixon, 318 Conn. 495, 511, 122 A.3d 542 (2015). ‘‘The first two
steps in the Golding analysis address the reviewability of the claim, while
the last two steps involve the merits of the claim.’’ (Internal quotation marks
omitted.) State v. Britton, 283 Conn. 598, 615, 929 A.2d 312 (2007). ‘‘The
appellate tribunal is free, therefore, to respond to the defendant’s claim by
focusing on whichever condition is most relevant in the particular circum-
stances.’’ (Internal quotation marks omitted.) State v. Dixon, supra, 511.
   9
     The state further argues that the defendant has abandoned or, alterna-
tively, inadequately briefed any evidentiary claim because he ‘‘appears to
limit his appellate claims to his assertion that his constitutional right to
confrontation was violated.’’ The state is correct that the defendant framed
this issue in his statement of the issues as ‘‘whether the defendant’s sixth
amendment right to confrontation was violated when Detective Ditria testi-
fied without specialized knowledge regarding the whereabouts of the defen-
dant based upon his interpretation of cell phone records.’’ In advancing this
claim, however, the defendant has consistently argued that the violation of
his confrontation rights stems from the court’s evidentiary error in permitting
Ditria to interpret his cell phone records without qualifying him as an expert
witness. The defendant has thoroughly briefed why testimony concerning
cell site analysis should be admitted only through an expert witness. Accord-
ingly, we conclude that the defendant has not abandoned or inadequately
briefed this threshold evidentiary claim.
   10
      ‘‘Cell sites’’ are often referred to as ‘‘cell towers.’’ We believe that the
term cell site is more precise. The primary purpose of a cell site ‘‘is to
elevate antennas that transmit and receive radio-frequency (RF) signals
from’’ cell phones. M. Harris, Unison, How Cell Towers Work (2011), avail-
able       at    www.unisonsite.com/pdf/resource-center/How%20Towers%20
Work.pdf (last visited August 23, 2017). This purpose can be accomplished
by building an independent tower or by placing the cell site in common
structures such as buildings, water towers, bridges, tunnels, streetlights,
traffic lights, stadium lights, and billboards. Id.
   11
      This geographical coverage area is also known as a ‘‘cell,’’ ‘‘sector,’’ and
‘‘footprint.’’ See T-Mobile USA, Inc. v. City of Anacortes, 572 F.3d 987, 997
n.11 (9th Cir. 2009) (‘‘ ‘coverage footprint’ ’’); State v. Payne, supra, 440 Md.
692 (‘‘cell’’); United States v. Mack, Docket No. 3:13-cr-00054 (MPS), 2014
WL 6474329, *3 (D. Conn. November 19, 2014) (‘‘sector’’); United States v.
Davis, Docket No. 11-60285-CR, 2013 WL 2156659, *5 (S.D. Fla. May 17,
2013) (‘‘footprints of the sectors’’); T. Singal, Wireless Communications 99
(2011) (‘‘cell’’ or ‘‘footprint’’).
   12
      ‘‘Cells [or cell sectors] are always drawn as hexagons because it makes
it simpler and easier to show adjacent cells without any overlap. In reality,
the cell shape is closer to a circle but it may be affected by surrounding
buildings and other geographic features.’’ T. Singal, supra, p. 101.
   13
      ‘‘Commonly a cell [site] will have the first of the three antennas centered
on due North or 0 degrees. This antenna has a nominal area 120 degrees
wide which [covers] 60 degrees each side of due north. This antenna’s
nominal field [extends] from 300 degrees (-60 degrees) to 60 degrees and
is called either the north facing antenna or the Alpha antenna. The second
antenna is centered at 120 degrees and has a nominal coverage area [that
extends] from 60 degrees to 180 degrees, this antenna is referred to as the
southeast facing antenna or the Beta antenna. The third antenna nominally
covers the remaining area of the field; it is centered on 240 degrees and
nominally [extends] from 180 degrees to 300 degrees, this antenna is called
either the southwest facing antenna or the gamma antenna.’’ T. O’Connor,
supra, 3 Small Scale Digital Device Forensics J. 1; see also id., 1, 3 (depicting
different antenna orientation models).
   14
      The only way to prevent registration is by turning the cell phone off,
by putting it in ‘‘Airplane Mode,’’ or by placing it in a shielded container,
such as a Faraday bag. J. Beck et al., supra, 49 Crim. L. Bull. Art. 8, 3.
   15
      Cell site characteristics include whether maintenance or repairs are
being performed on a given cell site, the range of coverage, the wattage
output, the call capacity of a cell site, and the number and closeness of
neighboring cell sites that will be competing with the cell site in question
to produce the strongest, best quality signal in the area. A. Blank, supra, 18
Rich. J.L. & Tech. 6; J. Beck et al., supra, 49 Crim. L. Bull. Art. 8, 5–6.
Antenna characteristics include the number of antenna on the cell site, the
antenna’s height, the direction and angle of the antenna, and the call volume
of the antenna at any given time. A. Blank, supra, 4. Cell phone specific
characteristics include the wattage output and the generation of the cell
phone’s broadband capability. Id. Last, environmental and geographical fac-
tors include the weather, topography (e.g., height above sea level), and
density of physical structures in the area. Id., 6–7; J. Beck et al., supra, 5–6.
   16
      The information contained in call detail records is sometimes referred
to as cellular site location information, or CSLI. E.g., State v. Smith, 156
Conn. App. 537, 540, 554 n.4, 113 A.3d 103, cert. denied, 317 Conn. 910, 115
A.3d 1106 (2015); see also Commonwealth v. Estabrook, 472 Mass. 852, 853
n.2, 38 N.E.3d 231 (2015).
   17
      The methodology of estimating the shape and size of a cell sector is
sometimes referred to as ‘‘cell identification’’; Collins v. State, supra, 172
So. 3d 740; or ‘‘mapping’’; e.g., State v. Edwards, 325 Conn. 97, 121, 156
A.3d 506 (2017); United States v. Mack, supra, 2014 WL 6474329, *3; United
States v. Machado-Erazo, 950 F. Supp. 2d 49, 55–56 (D.D.C. 2013).
   18
      It appears that ‘‘sector’’ in these instructions refers to the RF antenna,
and thereby the cell sector, used. The instructional page titled ‘‘Sector
Layout’’ explains that ‘‘Sprint . . . cell sites can be set-up in a variety of
ways. . . . [N]ot every cell site has three sectors. Some may have two
sectors or may be omni sites. . . . The direction that the sector faces
depends on the need for coverage in a particular area.’’ The instructions
further explain Sprint’s labeling schemes for determining the directional
orientation of the azimuth’s face, which are designated as being an alpha
sector, beta sector, or gamma sector. None of the information provided by
Sprint explains the nautical directions associated with a particular sector
type (e.g., north, south, east, or west). Cf. T. O’Connor, supra, 3 Small Scale
Digital Device Forensics J. 1; footnote 14 of this opinion.
   19
      We observe that of the eight phone calls analyzed by Ditria, five had
different cell sites listed for the initiation and termination of the call. For
four of these calls, Ditria provided the address of only the first cell site,
and for one of these calls Ditria provided the address of only the last cell
site. Ditria did not explain to the jury that a cell phone might use multiple
cell sites or antennae during the course of a call or that he was, in some
instances, providing them with the address of only one of the cell sites used.
   20
      First, Ditria testified that around the time indicated on the Walmart
receipt the defendant’s cell phone ‘‘was hitting off the South Cliff Street
tower approximately one mile from the Walmart in Derby located in Anso-
nia.’’ Second, Ditria testified that around the time that the defendant checked
into the Comfort Inn, the defendant’s cell phone used a cell site located
‘‘on 280 Elm Street in Naugatuck, approximately point six miles from the
Comfort Inn motel.’’ Third, Ditria testified that around the time of the rob-
bery, the defendant’s cell phone used a cell site located on ‘‘Rimmon Street
in Seymour . . . approximately point eight miles from the Webster Bank.’’
Fourth, Ditria testified that at 12:20 p.m. on the day of the robbery, the
defendant’s cell phone used a cell site at ‘‘236 Pent Road in Beacon Falls,’’
which was ‘‘[a]pproximately 1000 feet, under a quarter of a mile’’ from the
Beacon Falls Police Department. Fifth, Ditria testified that at approximately
1 p.m. on the day of the robbery, the defendant’s cell phone used a cell site
at ‘‘1875 Noble Avenue in Bridgeport,’’ which was ‘‘[a]pproximately a quarter
mile.’’ Ditria did not explain what this cell site was a quarter mile from, but
it appears he was alluding to the area where the facsimile firearm was
recovered. Sixth, Ditria testified that around the time indicated on the Home
Depot receipt, the defendant’s cell phone used a cell site at ‘‘134 Roosevelt
Drive in Derby . . . approximately point six miles from the Home Depot
in Derby.’’ Seventh, Ditria testified that around the time that the defendant
checked into the Post Motor Inn, the defendant’s cell phone used a cell site
at ‘‘28 Orange Road in Orange,’’ which was ‘‘[a]pproximately point eight
miles from the Post Motor Inn.’’ Finally, Ditria testified that around the time
the defendant checked into the Super 8 Motel the defendant’s cell phone
was using a cell site located at ‘‘160 Wampus Lane in Milford,’’ which was
‘‘[a]pproximately one mile’’ from the Super 8 Motel.
   21
      See State v. Porter, 241 Conn. 57, 698 A.2d 739 (1997), cert. denied, 523
U.S. 1058, 118 S. Ct. 1384, 140 L. Ed. 2d 645 (1998).
   ‘‘A Porter analysis involves a two part inquiry that assesses the reliability
and relevance of the witness’ methods. . . . First, the party offering the
expert testimony must show that the expert’s methods for reaching his
conclusion are reliable. . . . Second, the proposed scientific testimony
must be demonstrably relevant to the facts of the particular case in which
it is offered, and not simply be valid in the abstract. . . . Put another way,
the proponent of scientific evidence must establish that the specific scientific
testimony at issue is, in fact, derived from and based [on] . . . [scientifically
reliable] methodology.’’ (Internal quotation marks omitted.) State v.
Edwards, supra, 325 Conn. 124.
   22
      We recognize that in Edwards ‘‘the state [did] not assert that Morris
did not provide expert testimony’’; State v. Edwards, supra, 325 Conn. 118;
and the court elsewhere concluded that ‘‘the trial court admitted Morris’
testimony as an expert witness . . . .’’ Id., 128. Indeed, the court initially
framed the issue presented on appeal only as whether the trial court improp-
erly admitted Morris’ testimony and maps ‘‘without determining that the
evidence was based on reliable scientific principles under State v. Porter,
241 Conn. 57, 80–90, 698 A.2d 739 (1997), cert. denied, 523 U.S. 1058, 118
S. Ct. 1384, 140 L. Ed. 2d 645 (1998).’’ State v. Edwards, supra, 118.
   Nevertheless, our Supreme Court’s holding does not appear to be dicta
because this discussion was not ‘‘merely [a] passing commentary’’ that went
‘‘beyond the facts at issue’’ and was ‘‘unnecessary to the holding in the
case.’’ (Internal quotation marks omitted.) Voris v. Molinaro, 302 Conn. 791,
797 n.6, 31 A.3d 363 (2011). Instead, the court was intentionally taking up,
discussing, and deciding a question germane to, though not necessarily
decisive of the controversy before it, i.e., whether historic cell site analysis
is the kind of scientific evidence that requires expert testimony and a Porter
hearing to ensure the reliability of the scientific principles underlying it.
See id. Moreover, even if our Supreme Court’s statements concerning the
need to qualify a witness as an expert before permitting him to testify
about historic cell site analysis was dicta, we conclude that it is persuasive
precedent. See id.
