                 This opinion is subject to revision before final
                        publication in the Pacific Reporter

                                 2018 UT 02


                                    IN THE

       SUPREME COURT OF THE STATE OF UTAH

                              STATE OF UTAH,
                                 Appellee,
                                       v.
                       CHRISTOPHER JOHN ELLIS,
                              Appellant.

                             No. 20150486
                         Filed January 23, 2018

                            On Direct Appeal

                    Third District, Salt Lake
             The Honorable Katie Bernards-Goodman
                        No. 131902294

                                 Attorneys:
  Karen A. Klucznik, Asst. Solic. Gen., Salt Lake City, for appellee
Alexandra S. McCallum, John K. West, Salt Lake City, for appellant

 ASSOCIATE CHIEF JUSTICE LEE authored the opinion of the Court, in
which CHIEF JUSTICE DURRANT, JUSTICE HIMONAS, JUSTICE PEARCE, and
                      JUDGE BROWN joined.
JUSTICE HIMONAS filed a concurring opinion, in which CHIEF JUSTICE
              DURRANT and JUDGE BROWN joined.

Having recused herself, JUSTICE DURHAM did not participate herein;
           DISTRICT COURT JUDGE JENNIFER BROWN sat.


   ASSOCIATE CHIEF JUSTICE LEE, opinion of the Court:
   ¶ 1 Christopher Ellis was found guilty of aggravated robbery
and possession of a firearm by a restricted person. We reverse the
aggravated robbery conviction but affirm the possession conviction.
   ¶ 2 We reverse the aggravated robbery conviction because we
find prejudicial error in the admission of preliminary hearing
                            STATE v. ELLIS
                         Opinion of the Court
testimony under rule 804 of the Utah Rules of Evidence. First, we
find that the district court erred in its determination that the witness
in question was unavailable for trial. We hold that unavailability
may not be established merely on the basis of an illness on the
particular day a trial is scheduled by the court; there must be a
showing that the illness is of such an extended duration that a
reasonable continuance would not allow the witness to testify. And
we find that the witness in question here was not unavailable under
the standard that we clarify herein. Second, as in State v. Goins, 2017
UT 61, --- P.3d ---, we find that the preliminary hearing testimony at
issue here was inadmissible because the defendant’s motive to cross-
examine witnesses at the preliminary hearing was not similar to the
one he would have at trial. And we reverse the aggravated robbery
conviction because we conclude that the preliminary hearing
testimony in this case was central to the prosecution’s case on this
charge.
    ¶ 3 We affirm the conviction on the possession charge despite
the fact that the State has not sought to defend the admissibility of
the evidence challenged by Ellis on appeal—field test results, offered
to confirm that a substance found on Ellis was marijuana. We affirm
this conviction on the basis of our determination that any error in
admitting this evidence was harmless.
                                       I
    ¶ 4 Shortly before closing time on February 14, 2013, a man
walked into Mini’s Cupcakes in Salt Lake City, pointed a handgun at
the store clerk, and demanded the contents of the cash register. The
store clerk, Dylan Weight, promptly complied, giving the man
nearly four hundred dollars, including a one-hundred dollar bill,
and the store’s receipts. The robber ordered Weight to get on his
belly, and the man rushed out the door.
    ¶ 5 Weight got to his feet and ran outside to see where the
robber was headed. He saw the man cross 1100 East but lost sight of
him as the man turned right on the next intersecting street. Weight
also dialed 911 on his cell phone.
   ¶ 6 Weight described the robber to the 911 operator as a
Mexican or Native American man in his mid-40s. He recounted that
the man wore a gray or green hoody and black pants and had “dark,
possibly longer hair.” Weight also described the handgun as “like a
Ruger” because of its shape and longer barrel, though he
acknowledged his lack of gun expertise.
   ¶ 7 As Weight called 911, Brandy Thomas was driving on 1100
East and noticed a man dart across the street in heavy traffic. Her
                                   2
                          Cite as: 2018 UT 02
                         Opinion of the Court
mother and two younger brothers were also in the car. Thomas
noticed the store clerk on the side of the road talking on his phone
and looking “really scared.” She thought the incident significant
enough to turn left and follow the man she had seen crossing traffic.
She then saw him get into a four-door sedan that she believed was a
gray or gold Nissan. She drove by the car slowly, and someone in
her car wrote down the license plate number.
    ¶ 8 After she picked up her boyfriend, Thomas returned to
Mini’s Cupcakes and told Weight what she had seen. The store clerk
relayed the license plate number to the 911 operator. The police
received the license plate number and found that it corresponded to
a gray Chevy Malibu registered to Christopher Ellis. The police in
the area set out to find the car. Soon after the search began, an officer
stopped at Ellis’s house, but Ellis was not there and police could not
locate the car.
    ¶ 9 Police later spotted the Malibu turning into a residential
alleyway. The officer followed the car but lost sight of it after the
driver shut off the lights and exited via another egress. Soon
thereafter an officer discovered the Malibu pulling into a 7-Eleven
convenience store and stopped the vehicle. Police found Ellis, who is
African-American, wearing a black leather jacket, a red shirt, blue
jeans, and a straw fedora. He also had short hair.
   ¶ 10 Ellis consented to a search, and police found $359.50 in his
front pocket, including a one-hundred dollar bill. Ellis insisted that
he received the cash from working temporary jobs and that he did
not use a bank. After the vehicle was seized and pursuant to a
warrant, officers also discovered two handguns inside the car’s
trunk. Police never recovered a hoody or any Mini’s Cupcakes
receipts.
    ¶ 11 The police also found a “clear baggy that contained a plant-
like substance” in Ellis’s pocket. Officer Wright later identified the
substance as marijuana from its look, smell, and texture. He
recognized it as marijuana based on nearly forty years of police
experience. Officer Wright also placed a leaf in a field test kit, and
the sample tested positive for marijuana.
    ¶ 12 The day following the robbery, police showed Weight and
Thomas an array of six black and white photographs, one of which
featured Ellis. Weight felt uncomfortable using black and white
pictures to identify the robber, so he did not choose a photograph.
Thomas selected someone other than Ellis.
  ¶ 13 Months later, police called Weight, Thomas, and Thomas’s
mother in for a live lineup. Ellis was the only person who appeared
                                   3
                             STATE v. ELLIS
                         Opinion of the Court
in both the photograph array and the live lineup. Additionally,
although Weight described the robber as having longer hair and no
noticeable accent, four of the men in the eight-person lineup were
bald and some spoke with accents. Upon hearing each man state
“Get your belly on the ground,” Weight “one hundred percent
confirmed” that Ellis was the robber. Thomas again selected
someone other than Ellis.
    ¶ 14 The State charged Ellis with one count of aggravated
robbery, a first degree felony, in violation of Utah Code section 76-6-
302. And because police found marijuana and handguns in Ellis’s
car, the State added one count of purchase, transfer, possession, or
use of a firearm by a restricted person, a third degree felony, in
violation of Utah Code section 76-10-503(3)(a).
    ¶ 15 Thomas testified at Ellis’s preliminary hearing. She
reiterated that while she drove along 1100 East, she saw a man run
across the street and get into a four-door sedan. She thought it
“really weird” that the man had crossed the street “in all the traffic.”
She also testified to giving the license plate number to the store clerk,
who relayed it to the 911 operator.
    ¶ 16 Thomas was scheduled to testify on the first day of Ellis’s
trial, but she refused to attend because she needed to tend to her
newborn. A week before trial she had given birth—several weeks
prematurely—and her baby had come home from the hospital just
three days before the trial began. The prosecutor explained to the
district court that although both mother and baby were at home,
“the baby is on oxygen, [and] has a heart monitor.” Thomas refused
to leave her newborn to testify at the trial, and the prosecutor argued
that the only way Thomas would testify was if he “haul[ed] her to
court,” a position he “found to be untenable.”
    ¶ 17 The State moved to admit Thomas’s preliminary hearing
testimony because defense counsel had cross-examined her at the
prior hearing. Defense counsel objected to the transcript’s admission,
arguing that certain issues were not brought up during the
preliminary hearing and that Ellis had a right to cross-examine
Thomas at trial. Ellis’s counsel requested a continuance, but the
prosecutor resisted, arguing that the case had already been
continued several times and all the State’s witnesses were “ready to
go.” The district court noted that its schedule was full for the next
several months, so the trial, if continued, would be pushed back
several months.
   ¶ 18 The court ultimately held Thomas to be “unavailable”
under rule 804(a)(4) of the Utah Rules of Evidence. Ellis’s counsel

                                   4
                         Cite as: 2018 UT 02
                         Opinion of the Court
argued that the rule required that a witness be permanently
unavailable because of illness, but the court noted that the language
of the rule required only an “existing” illness. The court ruled that
804(a)(4) unavailability “does not have to be permanent[;] it’s just
not available today.”
    ¶ 19 The prosecution read Thomas’s preliminary hearing
testimony to the jury at trial. Defense counsel renewed his objection
to Thomas’s testimony after the jury had heard it, but the court again
overruled the objection. The jury also heard testimony from the store
clerk and from the police officers who stopped and searched Ellis’s
vehicle.
    ¶ 20 Officer Wright testified in support of the possession of a
firearm by a restricted person charge. He gave his opinion that, as a
police officer with nearly forty years’ experience, the plant-like
substance found in Ellis’s pocket was marijuana. He also testified
that he placed a sample of the substance into the field test kit, and
the sample tested positive for marijuana. He explained the steps he
takes when performing the field test and stated that he performed
those exact steps with the substance found on Ellis. On cross-
examination Officer Wright admitted that although he had
“probably” performed this test more than one hundred times during
his career, he did not understand the science behind the test kit. He
could not identify any substances that could result in a false positive.
At the close of Officer Wright’s testimony, defense counsel moved to
strike the testimony for failing “scientific muster” and for lacking
foundation.
   ¶ 21 The jury found Ellis guilty on both counts. The court
subsequently sentenced him to an indeterminate sentence of five
years to life on the aggravated robbery charge and zero to five years
on the possession of a firearm charge, both sentences to run
concurrently.
                                   II
    ¶ 22 Ellis seeks reversal of both of the convictions entered
against him. He challenges the aggravated robbery conviction on the
ground that the preliminary hearing testimony of Brandy Thomas
was admitted in violation of rule 804 of the Utah Rules of Evidence
and the Confrontation Clause of the United States Constitution. Ellis
also challenges the possession of a firearm conviction. On this count
Ellis claims error in the admission of testimony regarding field test
results, offered to confirm that a substance found on Ellis was
marijuana. And he thus asserts a right to a new trial on both of the
charges against him.

                                   5
                             STATE v. ELLIS
                         Opinion of the Court
   ¶ 23 We reverse the aggravated robbery conviction, finding
reversible error under rule 804 without reaching Ellis’s constitutional
challenge under the Confrontation Clause. We affirm the possession
conviction on the basis of our determination of harmless error.
                                    A
    ¶ 24 Brandy Thomas’s preliminary hearing testimony was
hearsay. It was therefore admissible only if qualified under an
exception to the bar on hearsay in our rules of evidence. The
question presented here is whether this testimony could meet the
standards for a hearsay exception in rule 804. In invoking that rule at
trial the State asserted that Thomas was “unavailable as a witness”
under rule 804(a) and that the standards in rule 804(b)(1) were met—
that Thomas’s testimony was given in a prior hearing and Ellis had
“an opportunity and similar motive to develop it” by cross-
examination at the preliminary hearing. See UTAH R. EVID. 804(b)(1).
    ¶ 25 The district court found these standards to be satisfied. It
deemed Thomas “unavailable” under rule 804(a)(4) and found that
Ellis had an “opportunity and similar motive” to develop cross-
examination at the preliminary hearing. We disagree on both counts.
We conclude that Thomas was not unavailable and that Ellis did not
have a similar motive for cross-examination at the preliminary
hearing. And we reverse because we conclude that this error was a
material one.
                                    1
    ¶ 26 Rule 804(a) sets forth criteria for deeming a declarant
“unavailable as a witness.” UTAH R. EVID. 804(a). It says that a
declarant is unavailable if she “(1) is exempted from testifying about
the subject matter of the declarant’s statement because the court
rules that a privilege applies; (2) refuses to testify about the subject
matter despite a court order to do so; (3) testifies to not remembering
the subject matter; (4) cannot be present or testify at the trial or
hearing because of death or a then-existing infirmity, physical
illness, or mental illness; or (5) is absent from the trial or hearing and
the statement’s proponent has not been able, by process or other
reasonable means, to procure the declarant’s attendance.” Id.
    ¶ 27 The trial court found that Thomas was unavailable under
subsection (4). It noted that Thomas had a newborn baby with a
“then-existing” illness. And because the baby’s condition was a
serious one, to which the mother (Thomas) had understandably
indicated an intent to attend to on the date of the scheduled trial, the
court found that Thomas was unavailable. In so doing the court
rendered an interpretation of the standard set forth in subsection (4).
                                    6
                          Cite as: 2018 UT 02
                         Opinion of the Court
It said that the reference to “then-existing” illness requires only a
showing that the witness is ailing and “not available today [on the
date scheduled for trial].” (Emphasis added.) And because it was
apparently conceded that Thomas was unwilling to leave her baby’s
side in the baby’s then-current condition, the court found Thomas
unavailable without further inquiry into the expected length of the
condition or the possibility of Thomas appearing to testify at a later
date.
    ¶ 28 This was error. Rule 804(a)(4) admittedly speaks of a “then-
existing infirmity, physical illness, or mental illness.” And unlike
subsection (5), subsection (4) does not make express reference to
attempts, “by process or other reasonable means, to procure the
declarant’s attendance.” Id. 804(a)(4)–(5). But that does not mean that
any fleeting illness can be deemed to render a witness “unavailable”
under subsection (4). Unavailability is a term of art. And in the
context of rule 804(a), we think it clear that the notion of
unavailability implies more than a mere inability to appear on an
isolated date on which the trial happens to be scheduled.
   ¶ 29 The various subsections of rule 804(a) share at least one
component in common—they all involve a substantial barrier to the
witness testifying not just on an isolated date but over an extended
period of time. See id. 804(a)(1) (witness unavailable if “exempted
from testifying about the subject matter of the declarant’s statement
because the court rules that a privilege applies”); id. 804(a)(2)
(witness unavailable who “refuses to testify about the subject matter
despite a court order to do so”); id. 804(a)(3) (witness unavailable if
she “testifies to not remembering the subject matter”). We read rule
804(a)(4) in light of these surrounding provisions. In context, a
witness is not unavailable due to an illness just because she cannot
appear on the precise date when the trial has been scheduled.
    ¶ 30 To establish a witness’s unavailability under subsection (4)
the proponent must show that the witness “cannot be present or
testify at the trial.” Id. 804(a)(4) (emphasis added). If a witness has a
minor or fleeting illness that interferes with her ability to be present
on an isolated date, we would not say that she cannot be present at
the trial. Unavailability implies a more substantial, lasting barrier to
participation at trial. It can be said that a witness cannot be present at
the trial due to illness only when the illness is of sufficient severity
and duration that the witness is unable to be present over a period of
time within which the trial reasonably could be held.
   ¶ 31 Other courts have so held. In assessing whether an illness
prevents a witness from attending trial the court “must consider

                                    7
                             STATE v. ELLIS
                         Opinion of the Court
both the duration and the severity of the illness.” Burns v. Clusen, 798
F.2d 931, 937 (7th Cir. 1986). Thus, the question is not just whether
the witness is dealing with an illness that prevents her from
attending trial “today,” as the district court here concluded. If the
defendant does not object to a continuance and a reasonable
continuance would allow the witness to attend, then the witness
cannot be said to be unavailable. See United States v. McGowan, 590
F.3d 446, 455 (7th Cir. 2009) (“The duration of the illness need only
be in probability long enough so that . . . the trial cannot be
postponed.” (citation omitted)).
    ¶ 32 The illness at issue here was a further step removed.
Brandy Thomas herself was not suffering from an illness; her
unavailability was due to her need to care for her newborn baby.
That alone does not necessarily foreclose the applicability of
subsection (4). The rule’s reference to a “then-existing infirmity,
physical illness, or mental illness” conceivably could be understood
to encompass the need to care for another’s illness.1 But it certainly is
not enough to just allege that a witness is unavailable due to her
need to care for another. A further showing would be necessary. At a
minimum, the proponent of the testimony would have to show that
the witness’s caretaker responsibility is critical and that that
responsibility renders the witness unavailable for an extended
period of time.
    ¶ 33 No such showing was made here. As the State notes, the
baby’s condition was apparent—the baby was born prematurely and
was on oxygen and a heart monitor. That was enough to establish
the existence of a severe health condition. But there was no inquiry
into the likely duration of the condition, or into the possibility that
someone could take Thomas’s place in caring for the baby at some
point during the reasonable time within which a trial could be held.
And the failure of proof on those points is fatal.
    ¶ 34 The State says that “the prosecutor could not tell the court
whether the baby’s condition was long- or short-term.” But that just
highlights the problem. It was the prosecution’s burden to tell the
court whether the baby’s condition was long- or short-term and
whether Thomas was unavailable during the period in which the
trial could reasonably be held. See State v. Barela, 779 P.2d 1140, 1142
(Utah Ct. App. 1989) (the proponent of the statement “bears the

_____________________________________________________________
   1 We do not resolve that question conclusively here, as an answer
is not necessary to our resolution of this case.

                                   8
                          Cite as: 2018 UT 02
                          Opinion of the Court
burden of establishing unavailability by competent evidence”). The
absence of any proof on these points means that Brandy Thomas was
not shown to be unavailable under rule 804(a)(4).
                                    2
   ¶ 35 Rule 804(b) identifies categories of hearsay that are
admissible when a witness is unavailable to testify at trial. The
operative exception at issue here is in rule 804(b)(1). That exception
applies when the hearsay consists of “[f]ormer [t]estimony” that (A)
was given by “a witness at a trial, hearing, or lawful deposition,”
and (B) “is now offered against a party who had . . . an opportunity
and similar motive to develop it by direct, cross-, or redirect
examination.” UTAH R. EVID. 804(b)(1)(A)–(B).
    ¶ 36 The district court admitted Brandy Thomas’s preliminary
hearing testimony under this exception. It found that Ellis had a
sufficient “opportunity and similar motive” to develop Thomas’s
testimony under cross-examination at the preliminary hearing. And
it accordingly concluded that the standard in rule 804(b)(1) was
satisfied.
    ¶ 37 That conclusion was understandable under our precedent
at the time of the trial in this case. Our decision in State v. Brooks held
that rule 804 does not bar “testimony given in a preliminary hearing
from being admitted at trial.” 638 P.2d 537, 541 (Utah 1981). Thus,
Brooks provides a basis for the conclusion that Ellis had a sufficient
opportunity and motive to develop Brandy Thomas’s testimony on
cross-examination at the preliminary hearing. And if Brooks were
good law we would have to agree with the district court’s analysis
on this point.
    ¶ 38 Our Brooks decision has been overtaken, however. In State
v. Goins, we found that the premises of the Brooks decision had been
overtaken by a constitutional amendment—an amendment limiting
“‘the function of [preliminary] examination . . . to determining
whether probable cause exists.’” 2017 UT 61, ¶ 31, --- P.3d ---
(alterations in original) (quoting UTAH CONST. art. I, § 12). In light of
that amendment, our Goins opinion concluded that “the blanket
statement we issued in Brooks no longer rings true.” Id. ¶ 32.
   ¶ 39 In Goins we recognized that “magistrates can, in some
limited ways, assess credibility at a preliminary hearing.” Id. ¶ 33.
But we noted that the “reality of practice” in “many, if not most,”
cases is that defense counsel will lack the motive to utilize cross-
examination in the way it could be employed at trial. Id. ¶ 34. Thus,
our Goins decision stopped short of holding that “counsel never has
the same motive to develop testimony at a preliminary hearing as at
                                    9
                             STATE v. ELLIS
                         Opinion of the Court
trial.” Id. ¶ 35. But we identified some common limitations on cross-
examination at a preliminary hearing. And we conditioned the
admissibility of preliminary hearing testimony on a showing that
“defense counsel really did possess the same motive and was
permitted a full opportunity for cross-examination at the preliminary
hearing”—a showing that we conceded “might prove rare.” Id. ¶ 36.
    ¶ 40 Ellis is entitled to the benefit of the Goins analysis. See State
v. Guard, 2015 UT 96, ¶ 67, 371 P.3d 1 (providing for “retroactive
application to all cases pending on direct review of new rules of
criminal procedure announced in judicial decisions”). And Goins
forecloses the admissibility of the Thomas preliminary hearing
testimony. As in Goins, we conclude that “we have no basis to
conclude that [Ellis’s] counsel’s preliminary hearing motive to cross-
examine was similar to what would have existed at trial.” Goins, 2017
UT 61, ¶ 46. And we therefore hold that the district court erred in
admitting this testimony under rule 804(b)(1).
                                    3
    ¶ 41 A determination of error in admitting Thomas’s
preliminary hearing testimony is not alone enough to sustain a
reversal. We must also find that error prejudicial. Prejudice in this
setting requires a showing of a “reasonable likelihood” that the
decision to admit Thomas’s preliminary hearing testimony altered
the jury verdict. See State v. Richardson, 2013 UT 50, ¶ 40, 308 P.3d 526
(errors in interpreting rules of evidence require reversal when “there
is a ‘reasonable likelihood’ that the verdict would have been
different” (citation omitted)).
    ¶ 42 Prejudice analysis is counterfactual. To decide whether a
trial affected by error is reasonably likely to have turned out
differently we have to consider a hypothetical—an alternative
universe in which the trial went off without the error. In this case, for
example, Ellis asks us to assess the likely outcome of a trial in which
Thomas’s preliminary hearing testimony is eliminated and the jury is
left to consider the remainder of the prosecution’s case. We consider
that counterfactual,2 and we conclude that a jury in these
_____________________________________________________________
   2   This may not be the only way to frame the counterfactual
prejudice analysis in a case like this one. An alternative hypothetical
might inquire into the likely outcome of a trial in which Thomas
testifies in person (after a continuance) and is subject to cross-
examination—as that is another way to frame the alternative
universe in which there is no error in allowing the preliminary
                                                        (continued . . .)
                                   10
                          Cite as: 2018 UT 02
                         Opinion of the Court
circumstances is reasonably likely to have reached a different
verdict.
    ¶ 43 The prosecution characterized Thomas as “a key witness”
whose testimony was crucial to a “viable” prosecution. And we
agree. Thomas provided key pieces of evidence that the jury likely
credited. Most important, perhaps, was the crucial information
Thomas provided about what occurred after the clerk lost sight of
the robber. The prosecution emphasized this testimony during
closing argument. And we think the verdict might well have been
different without Thomas’s testimony.
   ¶ 44 Without Thomas’s testimony the jury would have heard
that an unknown witness had relayed the plate number to Weight.
And defense counsel could have exploited this uncertainty. The jury
would then have been left in the dark about the identity of the
witness, whether she had personal knowledge, what she actually
saw, how she transcribed the plate number, and whether she
accurately conveyed the information to the store clerk. In sum, the
jury could have doubted the accuracy of the license plate number
that led the police to stop Ellis’s car.
    ¶ 45 Thomas was also the only witness who could testify that
the robber fled in a car. The store clerk last saw the robber escaping
on foot. Thus, Thomas was the crucial link for what occurred after
Weight lost sight of the robber, providing her observations that a
man got into the same car that police later intercepted. The absence
of these factual connections could easily have caused the jury to
reasonably doubt Ellis’s guilt. For that reason we find that the
district court’s error was prejudicial, and thus that Ellis is entitled to
a new trial on the aggravated robbery charge.
                                    B
    ¶ 46 When police stopped Ellis at the 7-Eleven convenience
store they found a leafy substance in Ellis’s pocket. Officer Wright
later identified that substance as marijuana. Wright offered two
grounds for his conclusion that the leafy substance was marijuana:



   (continued . . .)

hearing testimony into evidence. But the parties here have framed
their arguments in terms of the evidence remaining after the
elimination of the Thomas testimony, and our analysis follows their
lead.

                                   11
                             STATE v. ELLIS
                         Opinion of the Court
(1) the results of a field test and (2) Wright’s observations based on
his experience and training over several decades as a police officer.
    ¶ 47 Ellis challenges the first of these grounds for the officer’s
testimony. Because Officer Wright was unable to explain the science
behind the test and could not identify substances that might result in
a false positive, Ellis claims that the field test results should not have
been admitted as evidence. The State does not defend the propriety
of the field test evidence but insists that any error in admitting this
testimony was harmless.
   ¶ 48 We agree. Officer Wright testified that he was trained to
identify marijuana in the police academy in 1976 and later by the
California Narcotics Association. He also explained that he had
worked as an officer for thirty-nine years and had significant
experience with marijuana. And Wright’s identification of marijuana,
in his words, was “almost exclusively” based on “just looking [at]
and smelling” the substance.
    ¶ 49 We think the jury could have credited—and likely did
credit—this testimony as independently sufficient. We see no reason
to doubt that a jury would question a veteran police officer’s ability
to identify marijuana from its look, feel, and smell, especially one
who has been specially trained on multiple occasions for just such a
task. And for that reason we think the admission of testimony about
field test results was harmless.
                                   III
   ¶ 50 For the above reasons we find reversible error in the
admission of Thomas’s preliminary hearing testimony but not in the
decision to allow Officer Wright to testify about field test results. We
accordingly affirm the possession of a firearm conviction but reverse
the aggravated robbery conviction and remand for a new trial.



   JUSTICE HIMONAS, concurring:

    ¶ 51 I concur in every aspect of Associate Chief Justice Lee’s
opinion. As expressed by the Associate Chief Justice, it was obvious
error for the district court to find Ms. Thomas unavailable. And that
error wasn’t harmless—had Ms. Thomas’s preliminary hearing
testimony been excluded, or had the trial been postponed until Ms.
Thomas could appear and be subject to cross examination, there’s a
reasonable likelihood that the jury’s verdict would have been
different.


                                   12
                         Cite as: 2018 UT __
                       Himonas J., concurring

    ¶ 52 I write separately to highlight an additional consideration
militating against finding the district court’s error harmless. In the
course of asking the district court to admit Ms. Thomas’s
preliminary hearing testimony, the line prosecutor assigned to this
case stated that, in his view, Ms. Thomas was “a key witness.” He
called her an “essential witness[]” and averred that she was so
critical to the State’s case that trial could “not proceed without [Ms.
Thomas’s testimony because] . . . the case is just not viable without
[that testimony].”
    ¶ 53 On appeal, however, the State urges us to find that
admitting Ms. Thomas’s preliminary hearing testimony was
harmless error. That is, the State urges us to conclude that the
prosecutor below—an experienced practitioner who had lived
closely with this case in the run up to trial—was mistaken when he
told the district court that the State could not, in good faith, proceed
to trial without Ms. Thomas’s testimony.
   ¶ 54 There is, of course, nothing improper about how the State
has proceeded here. Far from it—the State ably presented its
argument for harmlessness on appeal, and there’s absolutely no
indication in the record that the trial prosecutor misrepresented his
view of the importance of Ms. Thomas’s testimony. Additionally,
there are surely many circumstances in which we should not hold
the State to the line prosecutor’s pretrial assessment of a witness’s
importance. The evidence after trial almost always looks different
than it looked before—sometimes radically so, sometimes (like here)
only in the details of what was elicited at trial—so it’s possible that
evidence a prosecutor might think critically important before trial
has started appears insignificant after all the evidence is in.
    ¶ 55 But when a prosecutor has stated their belief that evidence
is important, I’d tread carefully before finding any error in admitting
it to be harmless. I’m concerned about the effect a finding of
harmlessness under these circumstances would have on both the
public’s perception of fairness and the incentives governing
prosecutorial choices.
    ¶ 56 As I’ve said, the State’s conduct in this case is beyond
reproach. But what message would it send the public (including
those caught up in the criminal justice system) if our trial courts
were to regularly admit testimony based, in part, on the State’s
representation that it’s crucial, only to have our appellate courts
affirm the resulting conviction because the error in admitting the
testimony was harmless? “Yes, the evidence was absolutely crucial
before your conviction. And, yes, it was error to admit it. But the

                                  13
                             STATE v. ELLIS
                        Himonas J., concurring


difference now is that you’ve been convicted. Now it’s clear the
evidence was unimportant. Now the error is of no consequence at
all.” This smacks of Kafka.
    ¶ 57 And what about future prosecutors? Every time we declare
an error to be harmless, the potential effect is to “encourage the State
to [solicit] it with impunity.” Harris v. State, 790 S.W.2d 568, 587 (Tex.
Crim. App. 1989) (en banc), overruled by Snowden v. State, 353 S.W.3d
815 (Tex. Crim. App. 2011); see also Goodwin v. State, 751 So. 2d 537,
546 (Fla. 1999) (harmless error analysis should proceed with an eye
toward “providing an incentive on the part of the State, as
beneficiary of the error, to refrain from causing error to occur in the
trial of a case”); cf. In re Janet S., 712 N.E.2d 422, 424 (Ill. App. Ct.
1999) (“To conclude that [the State’s failure to make an effort to
locate exculpatory evidence] is harmless error could encourage the
State to avoid looking for such documents and then argue after the
fact that such a search would have been a waste of time.”). Ex ante,
the more willing an appellate court is to find an error harmless
despite a prosecutor’s contrary representations to the trial court, the
greater the incentive for prosecutors to make such representations—
representations that cannot help but have an effect on the likelihood
that a court will erroneously allow the evidence in. We should take
care to ensure that the doctrines we apply on appeal don’t create an
incentive structure that’s reasonably likely to increase the overall
incidence of error below.




                                   14
