IN THE COURT OF APPEALS OF IOWA
No. 24-0742 Filed October 29, 2025
STATE OF IOWA, Plaintiff-Appellee,
vs.
ROBERT JOSEPH ARKFELD JR., Defendant-Appellant. ________________________________________________________________
Appeal from the Iowa District Court for Shelby County,
Jennifer Benson Bahr, Judge.
A defendant appeals his conviction for serious injury by intoxicated
operation of a motor vehicle. REVERSED AND REMANDED.
Robert G. Rehkemper (argued) of Gourley, Rehkemper, & Lindholm,
P.L.C., West Des Moines, for appellant.
Brenna Bird, Attorney General, and Kevin Cmelik (argued), Special
Counsel, for appellee.
Heard at oral argument by Greer, P.J., and Badding and Chicchelly, JJ. 2
BADDING, Judge.
At the end of a long day of harvesting, Robert Arkfeld was crossing a
highway in his tractor when a motorcyclist crashed into him and died. Arkfeld’s
urine later tested positive for cocaine metabolites. He was charged with homicide
by intoxicated operation of a motor vehicle, but a jury found him guilty of the lower
offense of serious injury by intoxicated operation in violation of Iowa Code
section 707.6A(4) (2022).
Arkfeld appeals, claiming the district court erred in denying his motion to
suppress because law enforcement lacked probable cause to transport him from
the crash scene to the sheriff’s office for an evaluation by a drug recognition expert
and because the search warrant authorizing withdrawal of blood and urine samples
was invalid. He also challenges the sufficiency of the evidence, the exclusion of
evidence about the motorcyclist’s intoxication, and the district court’s refusal to
give his proposed jury instructions on causation.
Although we find that the court correctly denied Arkfeld’s suppression
motion, we conclude under State v. Adams, 810 N.W.2d 365 (Iowa 2012) that the
State failed to offer sufficient evidence that Arkfeld’s intoxicated operation of the
tractor caused the motorcyclist’s death. We accordingly reverse Arkfeld’s
conviction for serious injury by intoxicated operation of a vehicle and remand for
entry of judgment on the lesser-included offense of operating while intoxicated. As
a result, we do not reach the evidentiary or instructional issues.
I. Background Facts and Proceedings
On September 22, 2022, Robert Arkfeld was in the middle of a busy harvest
season, working from sun-up until sun-down to get the crops out of the fields. As 3
the sun was setting on the day, Arkfeld started on his last task—moving an eighty-
foot auger to a nearby farm. Brandon Schwery, a young man who helped Arkfeld
farm, had just finished some mechanical work on a semi-truck and called Arkfeld
to see if he needed anything. Arkfeld asked Schwery for help with the auger.
The two men hooked the auger to Arkfeld’s tractor and got it lined up on a
gravel driveway abutting Highway 59 in Shelby County. Arkfeld was driving the
tractor with the auger, and Schwery was behind him in a pickup truck. As they
pulled up the driveway, Arkfeld switched the tractor’s perimeter lighting to highway
lights and turned the flashers on. Schwery would later testify that all the lighting
on the tractor is LED, “so they’re pretty bright lights.” Because it was dark outside
by then, Schwery also turned the truck’s flashers on as an “extra caution.”
Arkfeld waited at the driveway for five to ten minutes for traffic to pass by
on the highway. Schwery testified that Arkfeld wasn’t in a hurry and “was just
waiting to go” until he saw an opening. After “quite a bit of time,” Schwery saw the
auger in front of him start to move. Schwery could see the highway, but he couldn’t
see oncoming traffic from his position behind the tractor and auger. As the tractor
reached the center line, both men heard a bang and saw a motorcycle tumble away
from the tractor. Arkfeld called 911 and instructed Schwery to do the same. While
on the phone with dispatch, Schwery went to check on the motorcyclist but
immediately recognized that he had died. Meanwhile, Arkfeld moved the tractor
off the highway and waited for emergency personnel to arrive.
Captain Chad Butler of the Shelby County Sheriff’s Office got to the scene
at about 8:25 p.m. He spoke to Arkfeld, who was waiting by the tractor. Arkfeld
told Captain Butler that he didn’t see the motorcycle until the very last minute. After 4
ensuring that Arkfeld did not need medical attention, Captain Butler asked him to
stay by the tractor while he directed the scene and waited for the Iowa State Patrol
to arrive. Captain Butler later testified that although he was not focused on Arkfeld,
he did not observe any signs that Arkfeld was impaired by alcohol or drugs.
Trooper Adrian Long arrived at the scene around 9:00 p.m. After evaluating
the scene, he walked over to Arkfeld, who was still by the tractor. Trooper Long
testified that Arkfeld was “laying his head on the left rear tractor tire, almost kind of
like a lethargic type movement.” He brought Arkfeld to his squad car for an
interview. Once inside the car, Trooper Long read Arkfeld his Miranda rights and
asked him what happened. Arkfeld explained that he was pulling out of the
driveway and saw a light “but thought it was way down there.” When he was about
to the centerline of the highway, Arkfeld said that he saw the motorcyclist hit the
front of the tractor. Trooper Long asked Arkfeld whether he had ingested any
alcohol or drugs that night, and Arkfeld said no.
To eliminate “any and all factors for cause” of the accident, Trooper Long
testified that he asked Arkveld to perform three standardized field sobriety tests:
horizontal gaze nystagmus, walk-and-turn, and one-leg stand. Arkfeld agreed but
informed the trooper that he had glaucoma, tunnel vision, and bad knees. Trooper
Long testified that he observed “possible impairment” from Arkfeld’s performance
on the tests, which are only validated to detect alcohol intoxication. But Arkfeld
blew 0.00 on a preliminary breath test, and Trooper Long was not trained to detect
physical indicators of drug use. With alcohol ruled out—and Trooper Long later
admitting that he had “no idea” what was causing the possible impairment—he 5
transported Arkfeld to the sheriff’s office for an evaluation by Chief Deputy Cody
Eckles, a drug recognition expert.
Deputy Eckles performed a twelve-step drug recognition test, which he
found showed signs of a central nervous system stimulant, like cocaine. The signs
that the deputy observed, however, didn’t correlate to that drug category. For
instance, Deputy Eckles found that Arkfeld had horizontal gaze nystagmus, which
is associated with central nervous system depressants, such as alcohol. He also
found that Arkfeld’s pupils were normal, as was his pulse rate. But individuals who
are impaired by stimulants have dilated pupils and elevated pulses. The only
indicator consistent with use of a stimulant was Arkfeld’s slightly elevated blood
pressure. Without noting these discrepancies, Deputy Eckles applied for a search
warrant to authorize the withdrawal of blood and urine samples from Arkfeld.
The warrant was granted, and Arkfeld’s urine sample later tested positive
for three metabolites of cocaine.1 While Arkfeld was at the sheriff’s office, another
officer found a baggie of cocaine inside an eyeglass case that had been tossed
into a corn field near the crash site. DNA recovered from the glasses inside the
case matched Arkfeld’s DNA profile. Arkfeld was arrested and charged with
homicide by intoxicated operation of a vehicle in April 2023.
After conducting discovery, Arkfeld filed a motion to suppress arguing that
he was detained by Trooper Long and transported to the sheriff’s office without
probable cause. Arkfeld alternatively moved to suppress evidence obtained from
1 A blood sample was also obtained from Arkfeld pursuant to the search warrant,
but the district court prohibited the State from introducing evidence about the test results because the State failed to lay a proper foundation for that evidence. See State v. Shelton, 176 N.W.2d 159, 160 (Iowa 1970). 6
the search warrant, which he contended was based on an affidavit with false and
omitted statements. The district court denied the motion.
As the case neared the jury trial in March 2024, the court granted the State’s
motion in limine to exclude evidence that the motorcyclist had alcohol and
marijuana in his system when he died. The court also ruled that Arkfeld’s accident
reconstructionist could not testify about the motorcyclist’s speed before the crash.
But at trial, the State asked its own reconstructionist—Trooper Aaron Nordyke—to
testify about his speed calculation for the motorcyclist. Trooper Nordyke’s
calculation, which put the motorcycle traveling at fifty-six to fifty-seven miles per
hour at the start of its skid marks, had not been disclosed to the defense. Because
the State put the motorcyclist’s conduct at issue with that testimony, the court
revised its earlier ruling and allowed Arkfeld’s reconstructionist—Dan Billington—
to testify about his speed calculations. Billington’s calculations concluded that the
motorcyclist was traveling at approximately eighty-six miles per hour when he let
off the throttle, eight-one miles per hour at the start of the skid marks when he
began to apply the brakes, and sixty-five miles per hour at impact.
After four days of evidence and another day of deliberation, the jury found
Arkfeld guilty of serious injury by intoxicated operation of a motor vehicle. Arkfeld
appeals.
II. Motion to Suppress
Invoking the Fourth Amendment to the United States Constitution, Arkfeld
claims the district court erred in denying his motion to suppress for two reasons:
(1) Trooper Long lacked probable cause to detain and transport him to the sheriff’s
office for the drug evaluation by Deputy Eckles; and (2) the search warrant 7
application contained false statements, intentionally omitted material information,
and was not supported by probable cause. We review these constitutional claims
de novo. State v. Harbach, 3 N.W.3d 209, 217 (Iowa 2024).
A. Probable Cause for Transportation
The Fourth Amendment protects “[t]he right of the people to be secure in
their persons . . . against unreasonable searches and seizures.” U.S. Const.
amend. IV. Evidence obtained in violation of this provision is inadmissible, “no
matter how relevant or probative the evidence may be.” State v. Freeman, 705
N.W.2d 293, 297 (Iowa 2005) (citation omitted). A warrantless search or seizure
is per se unreasonable unless one of the exceptions to the warrant requirement
applies. State v. Bradford, 620 N.W.2d 503, 506 (Iowa 2000).
“One such exception is an investigatory ‘Terry’ stop.” Id. Under Terry,
“police may detain persons in the absence of probable cause if the police have
reasonable suspicion to believe criminal activity is taking place.” State v. Pals, 805
N.W.2d 767, 774 (Iowa 2011); see also Terry v. Ohio, 392 U.S. 1, 27 (1968).
Arkfeld argues that Trooper Long exceeded the scope of an allowable Terry stop
by transporting him to the sheriff’s office. As a result, Arkfeld contends the trooper
needed probable cause for the “investigative detention.” See Dunaway v. New
York, 442 U.S. 200, 214–15 (1979) (“Nothing is more clear than that the Fourth
Amendment was meant to prevent wholesale intrusions upon the personal security
of our citizenry, whether these intrusions be termed ‘arrests’ or ‘investigatory
detentions.’”). We agree.
As our supreme court recognized in Bradford, “the removal of a suspect
from the scene of the stop generally marks the point at which the Fourth 8
Amendment demands probable cause.” 620 N.W.2d at 507 (citation omitted). “In
such a case there is no such thing as a ‘Terry transportation.’” Id. The State
argues while that is “certainly true as applied to the facts of Bradford,” it should not
apply to operating while intoxicated cases. Because we are bound by our supreme
court’s precedent, we reject the State’s request to carve out an exception for that
category of cases.2 See State v. Beck, 854 N.W.2d 56, 64 (Iowa Ct. App. 2014)
(“We are not at liberty to overrule controlling supreme court precedent.”).
Turning to the question of probable cause, our supreme court has explained
that probable cause
exists when the facts and circumstances within the arresting officer’s knowledge would warrant a person of reasonable caution to believe that an offense is being committed. The facts must rise above mere suspicion but need not be strong enough to sustain a guilty conviction. All of the evidence available to the arresting officer may be considered, regardless of whether or not each component would support a finding of probable cause by itself. Seemingly innocent activities may combine with
2 The case that the State cites in support of this request—State v. Dennison, 571
N.W.2d 492 (Iowa 1997) (per curiam)—is distinguishable. The issue in Dennison was “whether the defendant was ‘arrested’ for purposes of the speedy indictment rule after law enforcement officers tested him to determine whether he was under the influence of alcohol and/or drugs.” 571 N.W.2d at 493. At the time, Iowa courts “had consistently interpreted Iowa Rule of Criminal Procedure 2.33(2)(a) as being triggered by a statutory arrest, not mere Fourth Amendment custody.” State v. Williams, 895 N.W.2d 856, 868 (Iowa 2017) (Mansfield, J., concurring specially); see also Dennison, 571 N.W.2d at 495 (“This court has also rejected the contention that a de facto arrest triggers the speedy indictment time.”). Thus, the Dennison court concluded there was no formal “arrest” within the meaning of the procedural rule because the implied consent statute “allows a police officer to request a chemical test without placing the individual under arrest.” Id. at 496. The speedy indictment rule is not at issue here, implied consent was not invoked, and we are not concerned with whether there was a statutory arrest; the question in this case is constitutional. See Bradford, 620 N.W.2d at 506 (“The Fourth Amendment’s protections are not limited to ‘traditional’ arrests; indeed, a clear deprivation of liberty caused by law enforcement officers without formal words is nonetheless an arrest.” (cleaned up)). 9
other factors to give an experienced police officer reasonable grounds to suspect wrongdoing.
Bradford, 620 N.W.2d at 508 (cleaned up). In reviewing the district court’s ruling
on this issue, we “consider both the evidence introduced at the suppression
hearing as well as the evidence introduced at trial.” State v. Palmer, 791
N.W.2d 840, 844 (Iowa 2010).
Because alcohol was ruled out by Trooper Long at the scene, Arkfeld
focuses on whether the trooper had reasonable grounds to believe that he had
ingested a controlled substance. He points out that no drugs or drug paraphernalia
were found at the scene before he was transported.3 He also notes that witnesses
denied seeing any physical indicators of drug use. Trooper Long did not smell any
drugs or masking odors, and he agreed that Arkfeld was quiet, calm, and
cooperative. Schwery also described Arkfeld as “normal” before the accident—
“[m]aybe a little tired, but nothing out of the ordinary.” And Captain Butler agreed
that he didn’t notice any signs that Arkfeld was impaired “by any sort of drug,
alcohol, or controlled substance” when he talked to him.
3 In arguing that probable cause existed for the detention, the State relies on facts
learned by law enforcement after Arkfeld was transported to the sheriff’s office, including the cocaine that was found in the corn field. However, for the probable- cause inquiry, we must confine our review to the information known by officers at the time Arkfeld was taken from the scene. Dist. of Columbia v. Wesby, 583 U.S. 48, 56–57 (2018) (“To determine whether an officer had probable cause for an arrest, we examine the events leading up to the arrest, and then decide whether these historical facts, viewed form the standpoint of an objectively reasonable police officer, amount to probable cause.” (cleaned up)); Children v. Burton, 331 N.W.2d 673, 680 (Iowa 1983) (“Facts that occur or come to light subsequent to the arrest are irrelevant to a determination of whether probable cause existed at the time of the arrest.”). 10
But even though he did not observe evidence of drug use, Trooper Long—
who had a longer and more focused interaction with Arkfeld than Captain Butler—
testified that he did observe signs at the crash scene that Arkfeld was impaired.
Those signs included bloodshot and watery eyes, mumbled speech, “unsteady gait
and/or unsteady balance,” “impairment of judgment,” and drowsiness. Trooper
Long testified that he also observed “clues of impairment” from the three field
sobriety tests, which Arkfeld failed. Although the trooper did not know what was
causing Arkfeld’s impairment, we have held that similar objective signs of
impairment are sufficient to establish probable cause for the issuance of a search
warrant. See State v. Wenzel, 987 N.W.2d 473, 483 (Iowa Ct. App. 2022)
(concluding a deputy’s observation of “bloodshot and watery eyes, slurred speech,
impaired judgment, and poor driving” provided probable cause to issue a search
warrant for a blood sample).
We think the same reasoning should apply here in the detention context.
As we said in Wenzel, “[w]hile objective observations, such as slurred speech, can
be indicia of intoxication by alcohol or by drugs, the more difficult task of identifying
the specific level of drug usage to show impairment should not serve as an
impediment to enforcement.” Id. Although Trooper Long was not trained as an
expert in drug recognition, he testified that he was trained to recognize physical
signs of a driver’s impairment. Id. at 485. Based on that training, the trooper
testified that Arkfeld was exhibiting “some kind of impairment.” “While there might
conceivably be innocent explanations, probable cause does not require certainty.”
State v. Tipton, 897 N.W.2d 653, 687 (Iowa 2017). “It requires only a probability
or substantial chance of criminal activity, not an actual showing of such activity.” 11
Dist. of Columbia v. Wesby, 583 U.S. 48, 57 (2018) (citation omitted). In sum,
probable cause “is not a high bar.” Id. (citation omitted).
Considering the totality of the circumstances, and giving deference to the
district court’s implicit credibility determination in favor of Trooper Long, see State
v. Hunt, 974 N.W.2d 493, 496 (Iowa 2022), we conclude the trooper had probable
cause to detain Arkfeld and transport him to the sheriff’s office.
B. Search Warrant
Arkfeld next claims that Deputy Eckles made “material misstatements” and
“intentional and/or reckless omissions of information” in the search warrant
application, which “undermined any probable cause conclusions” by the magistrate
who issued the warrant. He also claims that “even with the false statements and
without considering the omitted information, the search warrant application failed
to establish probable cause to withdraw” his urine and blood. We reject both
claims.
1. Material misstatements and omissions of information. As our
supreme court recently explained in Harbach:
Affidavits included in search warrant applications are presumed to be true. To overcome that presumption, a defendant challenging the veracity of a warrant application must make a “substantial preliminary showing that a false statement knowingly and intentionally, or with reckless disregard for the truth, was included by the affiant in the warrant affidavit.” If that preliminary showing is made, the court holds a hearing—referred to as a “Franks hearing”—where evidence may be presented to show whether the statements are knowingly or recklessly false. A defendant may also challenge the warrant application as intentionally omitting material facts that, if included, would cast doubt on the existence of probable cause. 12
3 N.W.3d at 218 (citations omitted); see also Franks v. Delaware, 438 U.S. 154,
155–56 (1978).
At the outset, the State contends the “issue of a false affidavit to support a
warrant application was not properly before” the district court because “Arkfeld did
not request a Franks hearing or make a preliminary showing of falsity.” Instead,
he raised the issue in his motion to suppress. The State objected to the procedural
defect in its resistance to the suppression motion and at the suppression hearing
when Arkfeld cross-examined Deputy Eckles about the issue. Cf. Harbach, 3
N.W.3d at 218 (finding the State waived any procedural challenges by not
objecting to the lack of a preliminary showing). The district court overruled the
State’s objection and allowed testimony about the Franks issue, which it then
denied in its ruling. Since an evidentiary hearing was held and a ruling was issued,
we elect to proceed to the merits.
Arkfeld’s motion to suppress asserted that Deputy Eckles knew field
sobriety tests are not validated for use in assessing drug impairment and that he
knew Arkfeld did not show signs of having used a central nervous system
stimulant, even though that’s what the deputy concluded was causing Arkfeld’s
impairment. His brief in support of the motion also argued that the deputy failed to
disclose that Arkfeld passed some of the drug recognition tests. Because that
information was omitted from the search warrant application, Arkfeld argued that
Deputy Eckles falsely or misleadingly swore that he had probable cause to believe
Arkfeld was “under the influence of alcohol and/or drugs.” The district court
rejected these arguments, concluding that Deputy Eckles “considered the testing
results as signs of impairment even if they did not conclusively prove impairment” 13
and that he was not required to disclose exculpatory information or identify the
specific drug category causing the impairment. We agree.
“The Franks doctrine applies to ‘situations involving the omission of crucial
information from a warrant application as well as the inclusion of inaccurate
information.’” Id. at 222 (citation omitted). “When a defendant challenges omitted
information,” as Arkfeld does here, “he must show ‘(1) that facts were omitted with
the intent to make, or in reckless disregard of whether they make, the affidavit
misleading; and (2) that the affidavit, if supplemented by the omitted information,
could not support a finding of probable cause.’” Id. (citation omitted). Arkfeld failed
to make that showing.
At the suppression hearing, Deputy Eckles agreed that the field sobriety
tests administered to Arkfeld—and described in the warrant application—had not
been validated to assess “any particular type of drug . . . other than alcohol.” But
the deputy testified the results can indicate impairment, which he defined to mean
the “inability to operate a motor vehicle safely.” Thus, in the warrant application,
Deputy Eckles listed the results of the field sobriety tests—including that Arkfeld
blew 0.00 on the preliminary breath test—as part of his observations of impairment.
Other signs of impairment listed in the application included Trooper Long’s
observations of Arkfeld at the scene, Arkfeld falling asleep on the way to the
sheriff’s office, and Arkfeld’s performance on the drug evaluation administered by
Deputy Eckles.
We do not consider these observable signs of impairment misleading, even
though the deputy did not include details about the limits of field sobriety testing,
the drug recognition tests Arkfeld passed, or the deputy’s suspicions about which 14
category of drugs might have caused Arkfeld’s impairment in the warrant
application. See id. at 224 (finding a “deputy’s failure to include every detail” about
a defendant’s injuries, which could explain his physical signs of impairment, “does
not make the affidavit misleading”). And there is no indication from the record that
Deputy Eckles intentionally or recklessly omitted these facts to make the
application misleading. Instead, when asked why the facts were not included, the
deputy testified that he didn’t think they were relevant. “An officer is not required
to include all facts in the warrant application, even those exculpatory to the
defendant.” Id. at 222. Nor is an officer’s concentration on facts supporting a
probable cause determination fatal to the warrant. See State v. Ripperger, 514
N.W.2d 740, 745 (Iowa Ct. App. 1994). Instead, the “core inquiry is whether the
issuing judge was presented with sufficient evidence to determine whether
probable cause existed under the totality of the circumstances.” Harbach, 3
N.W.3d at 223. We conclude that standard was met here.
2. Probable cause. We also conclude the search warrant application
on its face established probable cause to issue the warrant. See State v. Bracy,
971 N.W.2d 563, 567 (Iowa 2022) (“When reviewing a warrant application, we
examine only the information actually presented to the judge.” (cleaned up)).
The task of the issuing magistrate is simply to make a practical, common-sense decision whether, given all the circumstances set forth in the affidavit before him, including the “veracity” and “basis of knowledge” of persons supplying hearsay information, there is a fair probability that contraband or evidence of a crime will be found in a particular place. And the duty of a reviewing court is simply to ensure that the magistrate had a “substantial basis . . . for conclud[ing]” that probable cause existed. 15
Ripperger, 514 N.W.2d at 746 (quoting Illinois v. Gates, 462 U.S. 213, 238–39
(1983)).
As the above standard suggests, probable cause to search “requires a
probability determination as to the nexus between criminal activity, the things to be
seized, and the place to be searched.” State v. Seager, 341 N.W.2d 420, 427
(Iowa 1983). Arkfeld argues that “crucial nexus” is missing here because Deputy
Eckles did not “provide any correlation” between the observations of impairment
“and a conclusion that Arkfeld was suspected of being ‘under the influence of an
alcoholic beverage and/or other drug[s]’ or that evidence of such an offense would
be located in the place to be searched, Arkfeld’s bodily fluids.” We do not,
however, “strictly scrutinize the sufficiency of the underlying affidavit.” Bracy, 971
N.W.2d at 567 (citation omitted). Instead, we interpret it “in a common sense,
rather than a hypertechnical, manner.” Id. And because the law favors warrants,
see Harbach, 3 N.W.3d at 213, we must “draw all reasonable inferences to support
the judge’s finding of probable cause and decide close cases in favor of upholding
the validity of the warrant.” Baker, 925 N.W.2d at 614.
Under that standard, we agree with the district court that “[w]hen reading
the application as a whole, it is easily and logically inferable that law enforcement
believed that evidence of drug usage would be revealed from the collection and
testing of a bodily specimen.” Deputy Eckles described his training as a certified
drug recognition expert “specializing in the recognition of impairment caused by
alcohol and/or other drugs.” Based on that training, the deputy stated that he knew
“the collection of a specimen for forensic testing will aid my investigation and
determine what role the use of alcoholic beverages, controlled substances, or 16
drugs played in this traffic offense.” He then listed the signs of impairment that law
enforcement observed. Deputy Eckles was not required to “articulate which
claimed observations [were] related to suspected alcohol impairment and which
claimed observations were related to ‘other drug(s),’” as Arkfeld contends. See
Wenzel, 987 N.W.2d at 483–84 (rejecting a similar argument).
The totality of the circumstances presented in the warrant application—
including Arkfeld’s performance on the field sobriety tests and drug recognition
evaluation, along with the observations of his bloodshot and watery eyes, mumbled
speech, unsteady balance, impaired judgment, and drowsiness—were sufficient
to establish probable cause for the withdrawal of bodily specimens.
III. Sufficiency of the Evidence
The jury was instructed that to find Arkfeld guilty of serious injury by
intoxicated operation of a motor vehicle, the State was required to prove:
1. On or about the 22nd day of September, 2022, in Shelby County, Iowa, the defendant operated a motor vehicle while any amount of a controlled substance was present, as measured in the defendant’s urine. 2. The defendant’s act of operating a motor vehicle while any amount of a controlled substance was present, as measured by the defendant’s urine, unintentionally caused serious injury to [the motorcyclist]. Arkfeld claims the evidence was insufficient to establish the second
element—that his intoxicated driving caused the victim’s death.4 We review this
claim for the correction of errors at law. See State v. Cole, 3 N.W.3d 200, 203
4 Arkfeld also challenges the sufficiency of the evidence supporting the first element—whether he was operating the tractor while any amount of controlled substance was present. Because we conclude the evidence was insufficient to establish the second element, we do not reach this issue. 17
(Iowa 2024). “If substantial evidence supports the jury’s verdict, we will uphold it.
Substantial evidence is evidence sufficient to convince a rational trier of fact the
defendant is guilty beyond a reasonable doubt.” Id. (citations omitted). Although
we are “highly deferential to the jury’s verdict,” State v. Crawford, 972
N.W.2d 189, 202 (Iowa 2022), we conclude the State failed to present sufficient
evidence on the causation element.
Arkfeld’s argument is based on our supreme court’s opinion in State v.
Adams, 810 N.W.2d 365 (Iowa 2012), which the State contends “has vexed the
legal community” ever since it was issued. In Adams, the court examined the
State’s burden to prove causation under Iowa Code section 707.6A(1) for the
offense of homicide by intoxicated operation of a motor vehicle. 810 N.W.2d
at 368. Section 707.6A(1) provides that a person “commits a class ‘B’ felony when
the person unintentionally causes the death of another by operating a motor
vehicle while intoxicated, as prohibited by section 321J.2.” (Emphasis added.)
Section 707.6A(4), which criminalizes the lower offense of serious injury by
intoxicated operation, contains the same causation language: “A person commits
a class ‘D’ felony when the person unintentionally causes a serious injury, as
defined in section 702.18, by any of the means described in subsection 1 or 2.”
(Emphasis added.)
The defendant in Adams, who admitted to drinking three to five beers in the
five hours before he hit a bicyclist with his car, argued the word “by” in
section 707.6A expressed “a legislative intent that a conviction may be had under
the statute only upon proof that the defendant’s intoxication was the proximate
cause of another’s death.” 810 N.W.2d at 368. The State countered that “the 18
causal language ‘by’ only applies to ‘operating a motor vehicle.’” Id. Thus,
according to the State in Adams, “the death must be caused by the defendant’s
operation of a motor vehicle, and the defendant must be operating a motor vehicle
while he is intoxicated, but the State need not prove the victim’s death was caused
by the defendant’s intoxication to sustain a conviction.” Id. at 368–69.
The court sided with the defendant, concluding:
[I]t is the State’s burden under section 707.6A(1) to prove a causal connection between the defendant’s intoxicated driving and the victim’s death. Although the statute does not impose a burden on the State to prove a specific causal connection between the defendant’s intoxication and the victim’s death, it does require proof of a factual causal connection between a specific criminal act— “intoxicated driving”—and the victim’s death. Put another way, the statute demands more than mere proof that the defendant’s driving caused the death of another person. A defendant may be found guilty of homicide by vehicle only if the jury finds beyond a reasonable doubt that his criminal act of driving under the influence of alcohol caused the victim’s death.
Id. at 371.
The State argues that it met that burden here because there is “no
compelling evidence in this record that establishes that some other cause
interrupted the defendant’s act of intoxicated driving and the injury that occurred.
Otherwise stated, [the motorcyclist], perhaps drunk and speeding, died because
the defendant who was driving while drugged pulled into his path.” Arkfeld replies
that this argument misses the point. He contends the “crucial focus in a
prosecution under section 707.6A is the impact that a substance detected in a
person’s system would have had on the individual’s ability to safely operate a
motor vehicle. It is not enough to merely establish the substance was present and
the defendant’s driving caused the collision.” We agree. 19
As our supreme court recently reiterated, the factual causation analysis in
Adams requires the State to have “proof that the defendant was actually under the
influence, and not merely had vestiges of past [drug] use in their bloodstream.”
State v. McGee, 959 N.W.2d 432, 441 (Iowa 2021). That proof was missing here,
even upon viewing the evidence in the light most favorable to the State. See
Crawford, 972 N.W.2d at 202.
Although Arkfeld had three cocaine metabolites in his urine and cocaine
was found at the scene, he denied using any substances the day of the accident.
Cf. State v. Schaul, No. 15-0466, 2016 WL 2745934, at *3–4 (Iowa Ct. App.
May 11, 2016) (finding sufficient evidence that defendant’s intoxicated driving
caused the accident where the defendant admitted drinking eight to ten beers the
night of the collision). There was no evidence that Arkfeld was driving erratically
or showing signs of impairment before the accident. Cf. id. at *4 (discussing
testimony from an accident reconstructionist about the defendant’s reckless driving
and descriptions of the defendant’s impaired behavior from witnesses to the
accident). Schwery, who was helping Arkfeld move the auger, testified that Arkfeld
waited five to ten minutes “for the traffic to go” before pulling out onto the highway.
He also testified that Arkfeld was “[m]aybe a little tired” before the accident but
otherwise “seemed normal.” Captain Butler, who briefly interacted with Arkfeld
after the accident, did not observe any signs of intoxication. While Trooper Long
suspected that Arkfeld was impaired, the signs he detected—watery eyes,
mumbled speech, unsteady balance, and drowsiness—were subtle enough to be
missed by others at the scene. And they were also consistent with the rigor
involved in a long day of harvesting. 20
The State did present testimony from Deputy Eckles that the symptoms he
observed were consistent with the “downside” of cocaine use, which the deputy
explained was the body’s attempt to return to homeostasis after drug use. But the
State presented no evidence that those symptoms—or the metabolites in Arkfeld’s
urine (two of which were inactive)—impacted his driving. Cf. State v. Sallis,
No. 23-1588, 2025 WL 1066522, at *6 (Iowa Ct. App. Apr. 9, 2025) (finding
sufficient evidence that defendant’s intoxicated driving caused the victim’s death
where an expert testified about the impact of alcohol and marijuana on a
defendant’s driving); Schaul, 2016 WL 2745934, at *4 (same). Arkfeld, on the
other hand, called a pharmacologist as a witness at trial who stated there was no
way to determine whether the cocaine metabolites in Arkfeld’s urine had any
impact on his operation of the tractor. And the State’s own expert witness—a
criminalist in the toxicology section of the state crime lab—acknowledged that
cocaine metabolites can be detected in the urine up to three days after use.
We recognize that the State prosecuted Arkfeld under the third definition of
intoxication in Iowa Code section 321J.2(1)(c), which criminalizes operating
“[w]hile any amount of a controlled substance is present in the person.” Our
supreme court has held this provision creates a “per se ban” that “prohibit[s] people
from operating motor vehicles with controlled substances in their bodies, whether
or not they are under the influence.” State v. Comried, 693 N.W.2d 773, 776 (Iowa
2005); accord State v. Childs, 898 N.W.2d 177, 184 (Iowa 2017) (reaffirming the
holding in Comried on appeal from a conviction under section 321.2(1)(c)). But in
Adams, the court clarified that Comried “does not stand for the proposition that a
conviction under [section 707.6A(1)] may be sustained without proof of a causal 21
connection between the defendant’s intoxicated driving and a death. Any
language suggesting a contrary conclusion is dicta.” 810 N.W.2d at 371 n.6; but
see State v. Hennings, No. 22-0337, 2023 WL 2397045, at *3 (Iowa Ct. App.
Mar. 8, 2023) (finding the State “was not required to prove that the
methamphetamine in [defendant’s] system ‘in any way influenced’ her driving”
(citing Childs, 898 N.W.2d at 183)).
Returning to that key causal connection question, Arkfeld’s accident
reconstructionist measured the motorcyclist’s speed before impact at eighty-six
miles per hour and sixty-five miles per hour at impact. The reconstructionist also
testified that there is extensive research on the challenges for reasonable and
cautious motorists to identify motorcycles while driving, especially at night:
The interesting thing about the situation like this with Highway 59 is that, as I indicated before, you can see up to three miles away. And, in fact, at nighttime when a vehicle crests that hill the furthest away and it’s coming down the hill, you can see the light from that vehicle approaching. The distance however is so far off that when it’s that far away the headlights of that vehicle converge and it appears to be one single light of a vehicle three miles away. . . . The dynamics and the geometry of that intersection as you stare and look to the south along Highway 59 are such that a vehicle such as a motorcycle that only has one headlight, even if it is 2800 feet away, it appears in the same line or the same place within our field of view as the headlights of a vehicle three miles away.
He continued:
So you have still, if you saw a vehicle, a single light 3000 feet away, you may not realize that that’s a motorcycle. You may assume that that’s a car three miles away because you can’t see the—the spa[t]ial reference of that vehicle at nighttime. And that’s a problem. And it’s not just in this case. It’s in all cases involving motorcycles that have crashed or have accidents at nighttime.
The reconstructionist testified that he “saw no link or relationship to indicate there
was any type of impairment or any indication of impairment in Mr. Arkfeld’s 22
operation of the tractor.” Arkfeld’s drug recognition expert came to the same
conclusion. There was no contrary evidence from the State.
Under this record, we conclude there was insufficient evidence that the
victim’s death would not have occurred “in the absence of the defendant’s criminal
act—intoxicated driving.” Adams, 810 N.W.2d at 372, 373 n.9 (noting that a
“rational fact finder could have found Adams’ alleged intoxicated driving was not
the factual cause of [the victim’s] death” because a sober driver “would have struck
the victim,” who was wearing dark clothing and bicycling late at night on a busy
city street); see also State v. Wieskamp, 490 N.W.2d 566, 567 (Iowa Ct. App. 1992)
(concluding that “a sober driver driving with reasonable care would have struck the
victim lying in the street covered solely in dark clothing in an unlighted area of the
highway”).
We accordingly reverse Arkfeld’s conviction for serious injury by intoxicated
operation of a vehicle and remand for entry of judgment on the lesser-included
offense of operating while intoxicated. See State v. Morris, 677 N.W.2d 787, 788–
89 (Iowa 2004). Because of this resolution, we do not reach the evidentiary or
instructional issues raised on appeal.
REVERSED AND REMANDED.