RENDERED: AUGUST 1, 2025; 10:00 A.M. TO BE PUBLISHED
Commonwealth of Kentucky Court of Appeals NO. 2024-CA-0406-DG
SARAH PARR APPELLANT
ON REVIEW FROM FLOYD CIRCUIT COURT v. HONORABLE JOHNNY RAY HARRIS, JUDGE ACTION NO. 23-XX-00003
COMMONWEALTH OF KENTUCKY APPELLEE
OPINION AFFIRMING
** ** ** ** **
BEFORE: ACREE, EASTON, AND L. JONES, JUDGES.
EASTON, JUDGE: The Appellant Sarah Parr (“Parr”) asks this Court to reverse
the Floyd Circuit Court’s decision affirming her conviction for driving under the
influence (“DUI”) after a jury trial in the Floyd District Court. Parr argues that, in
DUI cases involving marijuana, the Commonwealth must present expert testimony
to explain blood test results and specifically to prove how the measured levels of
marijuana metabolites show impaired driving ability. We granted discretionary review to address this question. Because the Floyd Circuit Court correctly rejected
this argument, we affirm.
FACTUAL AND PROCEDURAL HISTORY
We must assess this case in the context of Parr’s motion for a directed
verdict. To properly do so, we have independently examined the trial proceedings
to relate a complete review of the evidence considered by the jury.
Parr has been a commercial driver for over thirty-five years. On
January 18, 2022, she was driving a Kenworth tractor truck with an attached
trailer. Earlier that day, she had delivered a load of DDGS, which stands for
Distiller’s Dried Grains and Solubles, a byproduct of ethanol production. As Parr
explained, DDGS may be used as chicken feed.
Parr had delivered the DDGS in Virginia. DDGS can have a strong
smell. After the delivery, Parr had DDGS residue on her, and she changed her
clothes. She put the spoiled clothes in a bag in the cab of the truck. Parr later
explained that DDGS smells like something fermented, but she did not believe
DDGS smells like marijuana.
After the delivery of the DDGS, Parr picked up a load of coke, a solid
fuel made from carbonized coal. She was to deliver this load of coke to Michigan.
She drove into Kentucky. At Pikeville, Parr got a little off course as she planned to
stop to have dinner. Parr remembers having a police vehicle in front of her as she
-2- drove toward Prestonsburg. Parr added that she broke her glasses when she got her
dinner. She is required to wear her glasses to drive, but, contrary to her attorney’s
later argument, Parr insists that the lack of glasses had no impact on her driving.
The journey from Pikeville to the place where Parr would stop was
about twenty miles. Parr admits that she may have swerved once when another
truck caused her to do so. She may also have crossed lines as she was coming to a
stop. She further described a maneuver which may have happened once during the
trip as she “danced the trailer” to see if a car (which she called a “bumper sniffer”)
was following too closely. But Parr denies the dangerous driving observed by the
two witnesses in the car behind her.
Thomas Combs and Sarah Slater1 were on a date. They had been to
Pikeville and were headed back to Prestonsburg. They pulled in behind Parr in
Pikeville and followed her until her arrest. They saw Parr swerving all over the
road. They became so alarmed that they called 911. During the audio of that call,
both are heard exclaiming about Parr almost wrecking with a comment about
approaching a rock wall. The dispatcher asked them to keep following with
emergency flashers on until police arrived.
1 We remind the trial courts about the importance of oversight in the making of the record. We have only the audio of the testimony of Slater as well as the direct examination of Officer David Duncan. The video was stuck on a laptop screen during the presentation of this evidence during the jury trial.
-3- Not wanting to call the witnesses liars,2 Parr testified that they must
have seen another tractor-trailer. Parr was unable to explain why the witnesses did
not confuse the vehicle they followed for miles with some other vehicle actually
pulled over by the police.
Officer David Duncan (“Duncan”) of the Prestonsburg Police
Department (“PPD”) himself saw Parr swerve on the road before she stopped. Parr
insists that she was not pulled over by the police. Parr says she had pulled over of
her own accord. Her phone had died, and she was consulting a paper map. She
saw the police officer behind her only after she stopped.
When he initially approached Parr, Duncan smelled marijuana from
the cab of the truck and on Parr. Duncan observed Parr’s red, glassy, bloodshot
eyes. Duncan had Parr come to the front of her truck. During this interaction, PPD
Detective Hutchinson, an officer with over 25 years of experience, arrived at the
scene to assist Duncan. He also smelled marijuana as Duncan had.
2 Much of the questioning by the Commonwealth during the jury trial was by argumentative questions to which Parr did not object. Of particular concern, were the repeated questions to Parr about other witnesses being liars. The factfinder determines the credibility of witnesses, not the attorneys or witnesses. Evidence of dishonesty is governed by Kentucky Rules of Evidence (“KRE”) 608 through opinion and reputation evidence with proper foundation. The Kentucky Supreme Court has made it clear that questions like those asked of Parr are improper. Moss v. Commonwealth, 949 S.W.2d 579, 583 (Ky. 1997). “Counsel should be sufficiently articulate to show the jury where the testimony of the witnesses differ without resort to blunt force.” Id. The number of times the prosecutor engaged in this tactic in this case may have approached palpable error, but such error was not argued in this appeal.
-4- Parr was cooperative. She consented to a search of her vehicle, and
no marijuana was found. She attempted to perform field sobriety tests (“FSTs”).
Duncan explained how he administered the three standard tests. The first is the
Horizontal Gaze Nystagmus (“HGN”) test measuring how the eyes react to
stimulus. After that was a walk-and-turn test, and finally a one-leg stand. Parr
exhibited various “clues” during these tests.3 With probable cause to continue the
DUI investigation, Duncan then asked if Parr would consent to a blood test, which
she did.
Duncan took Parr to a nearby hospital, and blood was drawn. The
blood4 was tested by Jody Snodgrass (“Snodgrass”) with one of the Kentucky State
Police laboratories. Snodgrass has over ten years of experience and has probably
performed over ten thousand analyses. The test of Parr’s blood showed a
measurement of 4 nanograms per milliliter of Delta 9 tetrahydrocannabinol
(“Delta-9 THC”) and 2 nanograms per milliliter of 11-Hydroxy-Delta 9 THC. The
parties argued about the proper lab standards in place at the time with respect to the
3 Parr said she had a “bad back” as a result of an accident in 2018 and suggests that this affected her ability to perform the tests. She did not offer any evidence of any medical diagnosis. The only record in evidence was the medical screening sheet from Parr’s arrest on January 18, 2022. This sheet simply noted that Parr is a truck driver with back pain and takes over-the-counter medication for such pain. 4 Parr’s counsel suggested in closing argument that the results may be because of testing the wrong blood, but there was no evidence of any irregularity with the chain of custody or how the blood was tested.
-5- latter number, which measures a metabolite or substance created through the
body’s elimination of Delta-9 THC. For reasons we will explain further, we will
focus on the Delta-9 THC number for our analysis.
Parr said she does not smoke marijuana and did not do so on the day
of her arrest. She also said she did not ingest marijuana in any other way. We note
here the suggestion by Parr’s counsel that CBD (abbreviation for cannabidiol) oil
applied by a person could cause such a positive result. As Snodgrass explained,
CBD would show a different substance, which was not found in this case. No
evidence was offered at trial or by avowal of CBD oil use by Parr.
In addition to her own testimony, Parr offered the observations of the
hospital phlebotomist and a deputy jailer who both observed Parr after her arrest.
Neither smelled marijuana on Parr. Both said that Parr did not exhibit signs of
being under the influence of anything when they interacted with her. Both
conceded though that they were not in a position to see how Parr operated her
tractor-trailer earlier that night.
Parr’s counsel made a general motion for directed verdict at the close
of the Commonwealth’s case and renewed it at the close of all evidence. The
district court denied the motion. The jury convicted Parr of DUI and sentenced her
-6- to serve fourteen days in jail with a $200 fine. The circuit court on direct appeal
affirmed. The case is now before us on discretionary review.5
STANDARD OF REVIEW
Although the specific question presented is whether an expert witness
is required to explain marijuana-related concentrations in the blood, the procedural
posture of this case asks the broader question of whether a directed verdict should
have been granted by the district court. “On appellate review, the test of a directed
verdict is, if under the evidence as a whole, it would be clearly unreasonable for a
jury to find guilt, only then the defendant is entitled to a directed verdict of
acquittal.” Commonwealth v. Benham, 816 S.W.2d 186, 187 (Ky. 1991).
ANALYSIS
We start with a belated argument about preservation of the error
claimed. At the close of the Commonwealth’s evidence Parr’s counsel made the
following motion for directed verdict: “The Commonwealth hasn’t proven its case
sufficiently to create a jury issue sufficient to put this in front of the jury, your
5 We understand the particular importance of clarifying what is or is not required to prove a marijuana DUI in Kentucky. Becoming effective in 2025, Kentucky has joined those states allowing medical use of marijuana. Kentucky Revised Statutes (“KRS”) Chapter 218B. In addition to those cases resulting from continuing and still illegal recreational use of marijuana, the Commonwealth must anticipate cases with defendants having a prescription for marijuana and the challenges presented by the impact of this prescribed medication in DUI prosecutions.
-7- Honor, so we move for a directed verdict of acquittal.”6 This statement of less than
ten seconds in length was the entire motion.
A proper motion for directed verdict must “identify the particular
charge the Commonwealth failed to prove, and must identify the particular
elements of that charge the Commonwealth failed to prove.” Ray v.
Commonwealth, 611 S.W.3d 250, 266 (Ky. 2020). There was only one charge in
this case but two elements – (1) operating of vehicle and (2) while impaired by
marijuana. There was no dispute about the first element, but Parr’s motion did not
specify any insufficiency of evidence of impairment by marijuana.
Nevertheless, in response to the directed verdict motion, the
Commonwealth outlined the evidence offered on both elements. Still, at no point,
did Parr’s counsel argue to the district court that the Commonwealth was required
to present expert testimony about how the specific levels found in Parr’s blood
caused impairment. When the case arrived in circuit court, the argument became
much more specific. Without any objection from the Commonwealth, the circuit
court stated it saw the question to be answered on appeal as whether the
Commonwealth failed to present sufficient evidence because it did not have an
expert witness to explain how the levels found in the blood test impaired Parr.
6 Trial Record, 4-25-23, at 5:09:33-5:09:42.
-8- The failure to make a proper directed verdict motion should have
limited the argument to review for palpable error. RCr7 10.26. But, on the direct
appeal to the circuit court, the Commonwealth did not raise any question of
preservation. Instead, the Commonwealth addressed the merits of the newly
specific argument. We will not address the preservation issue further in these
circumstances because we find no error, palpable or otherwise, by the district or
circuit court.
“(1) A person shall not operate or be in physical control of a motor
vehicle anywhere in this state: . . . (c) While under the influence of any other
substance or combination of substances which impairs one’s driving ability[.]”
KRS8 189A.010(1)(c). The statute further provides that, if certain substances are
found in a blood sample taken within two hours of operating a vehicle, then the
statute is violated. KRS 189A.010(1)(d). Marijuana is specifically excluded from
the list of such substances. KRS 189A.010(12).
Parr then argues that, because impairment must be proven in cases of
marijuana use, the law requires expert testimony to explain how the measured
levels in a blood test caused impairment. The argument is largely based on a
concurrence in Bridges v. Commonwealth, 845 S.W.2d 541 (Ky. 1993). Bridges
7 Kentucky Rules of Criminal Procedure.
-9- involved an alcohol DUI. Thus, any comments about DUI due to other substances
is dicta. Furthermore, a concurrence by two judges in the result of a case holds no
precedential value. See Ware v. Commonwealth, 47 S.W.3d 333, 334-35 (Ky.
2001).
In the Bridges concurrence, Justice Joseph Lambert said: “When the
violation is based on the use of another substance [not alcohol], there must be
proof that such substance is capable of impairing driving ability.” Bridges, supra,
at 543 (Lambert, J., concurring). Justice Reynolds joined this concurrence. From
here, Parr furthers her argument by pointing out that the original DUI statute
allowed conviction if the substance “may impair” driving ability, but a recent
change of the language replaced this phrase with “impairs.”
This change to KRS 189A.010(1)(c) was not recent. This change was
made in 1991,9 although there have been several changes to the overall statute
through the years, with the statute containing the “may impair” language at times.
It may be conceded that proof that something impairs is different from proof that
something may impair. But it does not follow that the Commonwealth must
provide expert testimony in every marijuana DUI case to prove that the measured
blood levels caused impairment.
9 1991 1st ex s, c15, §2 (eff. 7-1-91).
-10- Impairment and the cause of impairment are two different things.
Impairment may be proven in a number of ways. Impairment often may be
observed as evidenced by erratic driving. Yet such evidence is not required for a
DUI conviction. Hayden v. Commonwealth, 766 S.W.2d 956, 957 (Ky. App.
1989).
Standard FSTs may be evidence not only to support probable cause
for arrest (an issue to be addressed by suppression motions rather than in front of a
jury in DUI cases), but they are also evidence of impairment. HGN, walk-and-
turn, and one-leg-stand tests indicate psycho-motor deficits, including reaction
time, regardless of the cause of the impairment, which is a separate issue.
“There is no requirement to prove that field sobriety testing is
scientifically reliable.” Iraola-Lovaco v. Commonwealth, 586 S.W.3d 241, 245
(Ky. 2019). “Kentucky law is clear that evidence of FSTs is admissible and that
officers observing a defendant’s driving and physical condition may offer opinion
testimony that the defendant was intoxicated.” Id. (emphasis added). We
emphasize and in this quote because it separates the admissibility of FSTs from the
permissibility of an officer stating an opinion of intoxication from all that he or she
observes, not just one FST result in isolation.10
10 Duncan stated that he was taught in his training that marijuana use alone would not cause HGN.
-11- The evidence in this case includes the lab result of the 4 nanograms
per milliliter of Delta-9 THC in Parr’s blood. As this Court has recognized,
“Delta-9 THC (hereinafter referred to as ‘THC’) is the active metabolite in
marijuana and is what causes intoxication and impairment.” Lyons v.
Commonwealth, 632 S.W.3d 776, 778 n.3 (Ky. App. 2020). That scientific fact is
not debatable.
We may cite evidence in this record supplied by Parr to support this
point. In support of her suppression motion, Parr submitted a scientific article
about marijuana which recognize Delta-9 THC as what causes the psychoactive
effects of cannabis.11 This same article questions the ability to accurately correlate
blood plasma concentrations of Delta-9 THC to impairment effects. “Smoking
marijuana results in rapid absorption with peak THC plasma concentrations
occurring prior to the end of the smoking.”12 “Effects from smoking cannabis
products are felt within minutes and reach their peak in 10-30 minutes.”13
Despite the challenges presented by how rapidly Delta-9 THC is
processed by the body, some jurisdictions have tried to create per se statutory
11 Drugs and Human Performance Fact Sheets, NAT’L HIGHWAY TRAFFIC SAFETY ADMIN. 7, https://www.nhtsa.gov/sites/nhtsa.gov/files/809725-drugshumanperformfs.pdf (last visited Jul. 28, 2025). Record at 54. 12 Id. at 8. Record at 55. 13 Id. at 10. Record at 57.
-12- provisions similar to those for blood alcohol. For example, Ohio created a testing
process and has a per se rule of 2 nanograms per milliliter.14 The United Kingdom
similarly finds impairment at the same 2 nanograms level.15 Kentucky has not
legislated a per se level for marijuana instead leaving the factual determinations to
be based on all evidence presented relevant to impairment and separately to its
cause.
We will compare two cases to illustrate why the evidence in this case
was sufficient to sustain the conviction. In Lyons, a marijuana DUI case, the blood
test showed a higher level of Delta-9 THC than in Parr’s case. We held it was
error to allow the chemist who performed the blood test analysis to basically read
from materials about how levels could impact a person because there was no
showing of expertise for that witness about that subject or acceptability of the
materials cited. Lyons, supra, at 779.
The defendant in Lyons had admitted to smoking marijuana earlier.
We indicated that this fact alone was not enough to prove impairment. There was
no observation of erratic driving, and no FSTs had been performed. That was
14 Wong, et al., Establishing Legal Limits for Driving under the Influence of Marijuana, Injury Epidemiology 2014 1:26. Record at 30. 15 Id. Record at 31.
-13- insufficient evidence to prove marijuana caused impairment, regardless of the
Delta-9 THC levels.
By comparison, in Kidd v. Commonwealth, 146 S.W.3d 400 (Ky.
App. 2004), there was also a test result, but it was of urine, which is not an
indication of levels of Delta-9 THC; it simply verified that marijuana was
processed through the body of the defendant. Id. at 401. Other evidence included
the results of FSTs, which the defendant had “failed.” The arresting officer
smelled marijuana on the defendant. The officer also noticed red, glassy eyes. The
officer had not observed erratic driving and had pulled the defendant over due to
inoperable taillamps. That evidence was sufficient for conviction.
In Parr’s case, three people, including an officer, observed erratic and
frankly dangerous driving by Parr for up to twenty miles. Two officers smelled
marijuana on Parr and in her vehicle. She had red, glassy, bloodshot eyes when
she was stopped. She “failed” all three field sobriety tests. Her blood test showed
the presence of Delta-9 THC, the ingredient in marijuana that causes impairment.
There was no evidence of any other substance in Parr’s blood. Although no
marijuana was found during a search, the jury was entitled to infer from the rest of
the evidence that Parr smoked the marijuana she had and threw out any related
contraband which might have shown she smoked it. Applying the measure for a
directed verdict, the district court did not err in denying such a verdict.
-14- We note that even if the Bridges concurrence was the law, which it is
not, that standard was also met. Snodgrass said that Delta-9 THC is the “active”
ingredient in marijuana. It is this substance that has the “potential” to give a
person “the desired effects” from the marijuana, such as getting “high.” 16 In other
words, evidence presented in this case showed that Delta-9 THC was “capable” of
causing impairment.
We can foresee situations where either party may call expert witnesses
in marijuana DUI cases, not unlike those experts called in alcohol DUI cases, who
extrapolate from blood test results to explain how marijuana is processed by the
body and likely timelines for its impairing effects, although the difference between
how the body processes alcohol and marijuana may make this difficult. Some
cases may involve multiple substances with the interaction leading one of the
parties to call an expert witness about the cause of impairment. But these
situations are not presented here.
CONCLUSION
We hold that, in this DUI marijuana case, the Commonwealth was not
required to call an expert witness to explain how Parr’s blood test result showed
impairment or otherwise to establish impairment based on Parr’s blood test results.
16 Trial Record, 4-25-23, at 4:08:19-4:09:25.
-15- The Floyd Circuit Court did not err in affirming the denial of a directed verdict by
the Floyd District Court in Parr’s jury trial. The Floyd Circuit Court is
AFFIRMED.
ALL CONCUR.
BRIEFS FOR APPELLANT: BRIEF FOR APPELLEE:
Edward L. Cooley Russell Coleman Lexington, Kentucky Attorney General of Kentucky
J. Grant Burdette Assistant Solicitor General Frankfort, Kentucky
-16-