State v. Richard E. Houghton, Jr.

2015 WI 79

SUPREME COURT OF WISCONSIN
CASE NO.: 2013AP1581-CR
COMPLETE TITLE: State of Wisconsin,
Plaintiff-Respondent-Petitioner,
v.
Richard E. Houghton, Jr.,
Defendant-Appellant.

REVIEW OF A DECISION OF THE COURT OF APPEALS
(Reported at 354 Wis. 2d 623, 848 N.W.2d 904)
(Ct. App. 2014 – Unpublished)

OPINION FILED: July 14, 2015
SUBMITTED ON BRIEFS:
ORAL ARGUMENT: April 22, 2015

SOURCE OF APPEAL:
COURT: Circuit
COUNTY: Walworth
JUDGE: John R. Race

JUSTICES:
CONCURRED:
DISSENTED: ABRAHAMSON, BRADLEY, J.J., dissent. (Opinion
Filed.)
NOT PARTICIPATING:

ATTORNEYS:
For the plaintiff-respondent-petitioner, the cause was
argued by Tiffany M. Winter, assistant attorney general, with
whom on the briefs was Brad D. Schimel, attorney general.

For the defendant-appellant there was a brief by Andrew R.
Walter, Elkhorn, and oral argument by Andrew R. Walter.

An amicus curiae brief was filed by Hannah Schieber Jurss,
assistant state public defender, with whom on the brief was
Kelli S. Thompson, state public defender, on behalf of the
Office of the State Public Defender.
 2015 WI 79
NOTICE
This opinion is subject to further
editing and modification. The final
version will appear in the bound
volume of the official reports.
No. 2013AP1581-CR
(L.C. No. 2012CF187)

STATE OF WISCONSIN : IN SUPREME COURT

State of Wisconsin,

Plaintiff-Respondent-Petitioner,
FILED
v.
JUL 14, 2015
Richard E. Houghton, Jr.,
Diane M. Fremgen
Defendant-Appellant. Clerk of Supreme Court

REVIEW of a decision of the Court of Appeals. Reversed.

¶1 DAVID T. PROSSER, J. This is a review of an
unpublished decision of the court of appeals,1 which reversed a
judgment of conviction entered by the Walworth County Circuit
Court2 against Richard E. Houghton, Jr. (Houghton). Houghton
pled guilty to one count of possession of THC (greater than 200

grams) with intent to deliver, following the circuit court's

1
State v. Houghton, No. 2013AP1581-CR, unpublished slip op.
(Wis. Ct. App. May 7, 2014).
2
The Honorable John R. Race, Judge.
 No. 2013AP1581-CR

denial of Houghton's motion to suppress evidence obtained during
the course of a traffic stop.
¶2 This case presents questions related to the standard
necessary for police to lawfully initiate a traffic stop.
Specifically, we consider whether an officer's reasonable
suspicion that a motorist is committing a traffic violation is
always sufficient for the officer to stop the motorist, or
whether some stops require probable cause. We also examine
statutes related to the placement of objects in the front
windshield of an automobile, and weigh the effect of recent
developments in case law related to objectively reasonable
mistakes of law made by law enforcement officers.

¶3 Police Officer Jeff Price (Officer Price) pulled
Houghton over after Officer Price observed Houghton's vehicle
traveling on a highway without a front license plate and with an
air freshener and a GPS unit visible in the front windshield.
Upon approaching the vehicle, Officer Price detected the odor of
marijuana, which led him to conduct a search of Houghton's car.
The search revealed approximately 240 grams of marijuana as well
as various paraphernalia commonly used for packaging and
distributing marijuana.
¶4 Houghton argues that the stop was not an investigatory
stop, and thus probable cause was required. Houghton contends
that Officer Price lacked probable cause to stop Houghton's

vehicle, making the subsequent search unlawful. The State
counters that reasonable suspicion is sufficient for police
officers to initiate any type of traffic stop, and that Officer
2
 No. 2013AP1581-CR

Price had reasonable suspicion to pull Houghton over for a
violation of Wis. Stat. § 346.88(3)(b) (2011-12),3 "Obstruction
of operator's view or driving mechanism." The State argues in
the alternative that any mistake by Officer Price as to whether
Houghton was operating his vehicle illegally was objectively
reasonable, and that under the holding of the recent United
States Supreme Court case of Heien v. North Carolina, 574 U.S.
___, 135 S. Ct. 530 (2014), Officer Price had reasonable
suspicion to stop Houghton's vehicle for the perceived
violation.
¶5 We hold that an officer's reasonable suspicion that a
motorist is violating or has violated a traffic law is

sufficient for the officer to initiate a stop of the offending
vehicle. We also adopt the Supreme Court's holding in Heien
that an officer's objectively reasonable mistake of law may form
the basis for a finding of reasonable suspicion.
¶6 In this case, we hold that Wis. Stat. § 346.88 does
not create an absolute prohibition on any object being present
in the front windshield of a vehicle. However, Officer Price's
interpretation that the statute did create such a prohibition
was objectively reasonable. Accordingly, Officer Price had
reasonable suspicion to stop Houghton's vehicle, and it was not
error for the circuit court to deny Houghton's motion to
suppress. For these reasons, we reverse the court of appeals.

3
All subsequent references to the Wisconsin Statutes are to
the 2011-12 version unless otherwise indicated.

3
 No. 2013AP1581-CR

I. FACTUAL AND PROCEDURAL BACKGROUND
¶7 At approximately 12:30 p.m. on April 16, 2012, Village
of East Troy Police Officer Jeff Price was on duty in a marked
squad car on the shoulder of Highway 20, facing east, near
Townline Road in East Troy. Around that time, Officer Price saw
a blue Ford Taurus traveling westbound on Highway 20. The car
had no front license plate, and an air freshener suspended from
the rearview mirror and a GPS unit were visible through the
front windshield. Officer Price did a U-turn, activated his
squad car's emergency lights, and pulled the Taurus over.
¶8 Officer Price approached the Taurus and obtained
identification from the occupants. The car, which had a

Michigan license plate attached to the back, was driven by the
defendant, Richard E. Houghton, Jr., who is a resident of
Michigan. In the front passenger seat of the car was James J.
Taracek (Taracek), Houghton's step-brother and a resident of
East Troy. After running a check on both Houghton and Taracek,
Officer Price returned to the the Taurus, this time approaching
the passenger side. As he approached, Officer Price smelled the
odor of marijuana coming from the car.
¶9 Officer Price searched the car and found the
following: "two partially smoked marijuana cigarettes, a pack of
zig-zag rolling paper, a piece of PVC tubing with a screen taped
on one end, a large zip-lock bag containing green plant

material, three smaller sandwich bags containing green plant
material, a 150 count pack of sandwich bags, and an AMS digital
scale with traces of green plant material on the weighing base."
4
 No. 2013AP1581-CR

The "green plant material" tested positive for
Tetrahydrocannabinol (THC), the active ingredient in marijuana.
The large "zip-lock" bag contained approximately 140 grams of
marijuana, the three smaller sandwich bags each contained
approximately 30 grams of marijuana, and the PVC tube contained
approximately 9 grams of marijuana.
¶10 In an information filed on June 5, 2012, Houghton was
charged with one count of possession with intent to deliver THC
(200 to 1000 grams), contrary to Wis. Stat. § 961.41(1m)(h)2.
On July 31, Houghton filed a motion with the circuit court
seeking suppression of the evidence obtained during the search
of his vehicle. Houghton argued that the lack of a front

license plate on his car and the items in his windshield were
not violations of Wisconsin law. Houghton contended that
"because no traffic violations occurred, [Officer Price] lacked
the reasonable suspicion to justify a Terry stop."4 Therefore,
Houghton argued, the stop violated his Fourth Amendment right
against unreasonable search and seizure.
¶11 The State answered Houghton's motion to suppress on
October 16. The State argued that Officer Price had reasonable
suspicion to stop Houghton for three observed violations: the

4
Terry v. Ohio, 392 U.S. 1 (1968).

5
 No. 2013AP1581-CR

absence of a front license plate, the items in the front
windshield, and a missing side mirror.5
¶12 The circuit court held a motion hearing on November 2,
at which Officer Price testified briefly about his encounter
with Houghton. At the end of the hearing, the circuit court
denied the motion. The court was equivocal about whether the
GPS unit and air freshener were statutory violations, noting
that "there must be a zillion cars driving around with air
fresheners and not very many of them would get stopped by the
traffic officer. They've got better things to do." However,
the court continued, "the princip[al] reason for the stop that
creates this reasonable and articulable suspicion is the front

license plate missing from a vehicle, missing on Wisconsin roads
when Wisconsin requires two plates."
¶13 After denial of his motion to suppress, Houghton pled
guilty to the count as charged at a hearing on February 13,
2013. As part of the plea agreement, the State recommended a
two-year sentence consisting of one year of imprisonment and one
year of extended supervision, imposed and stayed on the
condition that Houghton complete two years of probation and pay
a $500 fine plus costs. After a plea colloquy, the court

5
Houghton's car was missing the mirror lens on the
passenger side. However, Officer Price did not notice the lens
was missing from the mirror housing until after he stopped
Houghton. The State does not argue in this appeal that the
missing mirror lens gave Officer Price reasonable suspicion to
stop Houghton.

6
 No. 2013AP1581-CR

entered a judgment of conviction and accepted the sentence
recommendation, allowing for the possibility that Houghton would
serve probation in Michigan.
¶14 Houghton appealed his conviction. On appeal, Houghton
argued that the circuit court erred by denying his motion to
suppress evidence. Houghton maintained his argument that
Officer Price lacked reasonable suspicion to stop Houghton's
vehicle. The State conceded that Officer Price made a mistake
of law with regard to the license plate requirement. The State
also conceded that under State v. Longcore, 226 Wis. 2d 1, 9,
594 N.W.2d 412 (Ct. App. 1999), a mistake of law could not form
the basis for a traffic stop. The State argued, however, that

the items in the front windshield of Houghton's car gave Officer
Price sufficient reason to pull Houghton over.
¶15 In an unpublished per curiam decision, the court of
appeals reversed the judgment of conviction and remanded the
case to the circuit court. State v. Houghton, No. 2013AP1581-
CR, unpublished slip op. (Wis. Ct. App. May 7, 2014). The court
provided little explanation for its ruling, noting that:

the only objects near Houghton's front windshield were
a standard-size, pine-tree-shaped air freshener
hanging from the rearview mirror and a three-by-five-
inch GPS unit attached to the lower left-hand corner.
On these facts, we are not persuaded that there was
probable cause to conclude that a violation of
§ 346.88(3)(b) had occurred.
Id. at 5.
¶16 The court of appeals did acknowledge that the Supreme
Court had recently granted certiorari in Heien v. North

7
 No. 2013AP1581-CR

Carolina, 749 S.E.2d 278 (N.C. 2013), which addressed whether a
reasonable mistake of law could provide grounds for a traffic
stop. Houghton, No. 2013AP1581-CR, at 4 n.3. The court noted
that the decision in Heien could place the holding of Longcore
in doubt, and "suppose[d] the State [could] petition the
Wisconsin Supreme Court for review and then ask that the
petition be held in abeyance pending the outcome in Heien." Id.
¶17 The State petitioned this court for review and
requested that we hold the petition in abeyance pending
resolution of Heien. Following the release of the opinion in
Heien, this court granted review on January 13, 2015.
II. STANDARD OF REVIEW

¶18 Whether reasonable suspicion or probable cause is
necessary for a law enforcement officer to stop a vehicle is a
question of law we review de novo. See State v. Kramer, 2001 WI
132, ¶17, 248 Wis. 2d 1009, 637 N.W.2d 35. Whether a statute
has been properly interpreted and applied also is a question of
law we review de novo, but we do so "while benefitting from the
analyses of the court of appeals and circuit court." 118th St.
Kenosha, LLC v. DOT, 2014 WI 125, ¶19, 359 Wis. 2d 30, 41
N.W.2d 486 (quoting 260 N. 12th St., LLC v. DOT, 2011 WI 103,
¶39, 338 Wis. 2d 34, 808 N.W.2d 372). Finally, whether a
defendant's constitutional rights were violated is a question of
constitutional fact subject to a two-step standard of review.
State v. Phillips, 218 Wis. 2d 180, 189, 577 N.W.2d 794 (1998).
First, we uphold the circuit court's findings of historical fact
unless they are clearly erroneous. State v. Williams, 2002 WI
8
 No. 2013AP1581-CR

94, ¶17, 255 Wis. 2d 1, 646 N.W.2d 834. Then, we review the
circuit court's determination of the constitutional question de
novo. Id.
III. DISCUSSION
¶19 We begin by reviewing the law relating to
investigatory traffic stops, then examine the evolution of case
law involving stops predicated on reasonable mistakes of law.
We then turn to an analysis of the relevant statutes in this
case and conclude by applying the relevant law to the facts.
A. Probable Cause and Reasonable Suspicion
¶20 Terry v. Ohio, 392 U.S. 1 (1968), is the seminal case
on reasonable suspicion as justification for conducting

investigatory stops. In Terry, the defendant was convicted of
carrying a concealed weapon. Id. at 4. The arresting officer,
a veteran detective with almost 40 years of experience,
confronted Terry and his associates after observing them engage
in a pattern of suspicious behavior. Id. at 5-7. After
speaking to the men briefly, the detective grabbed Terry, spun
him around, and performed a pat down search. Id. at 7. The
search revealed a .38 caliber revolver in Terry's coat pocket.
Id. Terry moved to suppress the evidence, arguing that the
detective lacked probable cause to conduct the search. Id. at
7-8.
¶21 The Supreme Court affirmed Terry's conviction, holding
that "a police officer may in appropriate circumstances and in
an appropriate manner approach a person for purposes of
investigating possibly criminal behavior even though there is no
9
 No. 2013AP1581-CR

probable cause to make an arrest." Id. at 22. In order to
justify such a seizure, police must have reasonable suspicion
that a crime or violation has been or will be committed; that
is, "the police officer must be able to point to specific and
articulable facts which, taken together with rational inferences
from those facts, reasonably warrant that intrusion." Id. at
21. This "reasonable suspicion" standard was understood to be a
lower standard than probable cause. See id. at 35-36 (Douglas,
J., dissenting).
¶22 In Berkemer v. McCarty, 468 U.S. 420 (1984), the Court
extended the reasoning underlying Terry to include traffic
stops, holding that a police officer "who lacks probable cause

but whose 'observations lead him reasonably to suspect' that a
particular person has committed, is committing, or is about to
commit" a violation may conduct a traffic stop in order to
"'investigate the circumstances that provoke suspicion.'" See
id. at 439 (citation omitted). In other words, while probable
cause is enough to justify a traffic stop, probable cause is not
indispensable to justify a traffic stop. Rather, police
officers who reasonably suspect an individual is breaking the
law are permitted to conduct a traffic stop "to try to obtain
information confirming or dispelling the officer's suspicions."
Id.
¶23 Twelve years after Berkemer, the Supreme Court
decided Whren v. United States, 517 U.S. 806 (1996). In Whren,
the Court addressed whether temporarily detaining "a motorist
who the police have probable cause to believe has committed a
10
 No. 2013AP1581-CR

civil traffic violation is inconsistent with the Fourth
Amendment's prohibition against unreasonable seizures unless a
reasonable officer would have been motivated to stop the car by
a desire to enforce the traffic laws." Id. at 808.
¶24 On June 10, 1993, D.C. Metro Police officers were
patrolling an area of the city known for drug activity. Id.
The officers grew suspicious of a vehicle with temporary plates
and "youthful occupants" after seeing the driver of the vehicle
"looking down into the lap of the passenger at his right." Id.
The officers stopped the vehicle after observing it driving
erratically, and upon approaching the vehicle, they observed
Whren in possession of crack cocaine. Id. at 809. Whren was

arrested and charged with multiple drug violations. Id. Prior
to trial, the defense moved to suppress the evidence on the
theory that the officers' "ground for approaching the vehicle——
to give the driver a warning concerning the traffic violation——
was pretextual." Id. at 809.
¶25 In an opinion by Justice Scalia, a unanimous Court
held that the brief detention of a motorist who police have
probable cause to believe has violated a traffic law is not an
unreasonable search or seizure within the meaning of the Fourth
Amendment, even if the officer would not have initiated the stop
without some additional law enforcement objective. Id. at 808,
818-19. In other words, pretextual traffic stops——stops
designed to investigate violations not related to the observed
violation——are not per se unreasonable under the Fourth
Amendment.
11
 No. 2013AP1581-CR

¶26 Since Whren, some have sought deeper meaning in the
Court's assertion that, "As a general matter, the decision to
stop an automobile is reasonable where the police have probable
cause to believe that a traffic violation has occurred." Id. at
810 (emphasis added). Some courts interpreted Whren to mean
that probable cause——not reasonable suspicion——is required for a
traffic stop to be reasonable. See United States v. Delfin-
Colina, 464 F.3d 392, 396 (3d Cir. 2006) (discussing the
uncertainty raised by Whren).
¶27 The existence of multiple standards necessary to
justify traffic stops in Wisconsin was implied in State v.
Gaulrapp, 207 Wis. 2d 600, 558 N.W.2d 696 (Ct. App. 1996). In

Gaulrapp, the court of appeals stated that a "traffic stop is
generally reasonable if the officers have probable cause to
believe that a traffic violation has occurred, or have grounds
to reasonably suspect a violation has been or will be
committed." Id. at 605 (citations omitted). This dual-standard
analysis continued in Longcore when the court of appeals noted
that the officer "did not act upon a suspicion that warranted
further investigation, but on his observation of a violation
being committed in his presence," thus requiring the officer's
observations to meet the probable cause standard. Longcore, 226
Wis. 2d at 8-9 (footnote omitted).
¶28 Houghton urges this court to hold that this dual
standard is correct——that an investigative stop may be based on
reasonable suspicion, but a stop for an observed violation must
be based on probable cause. He argues that our decision in
12
 No. 2013AP1581-CR

State v. Popke, 2009 WI 37, ¶11, 317 Wis. 2d 118, 765
N.W.2d 569, recognized this distinction by citing Gaulrapp
multiple times, and that stare decisis dictates that we adhere
to it. Houghton also argues that this dual standard provides
proper protection to citizens' Fourth Amendment rights.
¶29 It is undisputed that traffic stops must be reasonable
under the circumstances. Gaulrapp, 207 Wis. 2d at 605. It is
also widely accepted that traffic stops may be justified by
either probable cause or reasonable suspicion. Popke, 317
Wis. 2d 118, ¶23. The question here is whether this "either/or"
principle means that reasonable suspicion will always suffice to
initiate a traffic stop, or whether the nature of certain types

of stops requires that a higher standard be met in those stops.
¶30 We conclude that reasonable suspicion that a traffic
law has been or is being violated is sufficient to justify all
traffic stops.6 The prevailing case law instructs that this is
so. See, e.g., Delfin-Colina, 464 F.3d at 396 ("the Second,
Sixth, Eighth, Ninth, Tenth and Eleventh Circuits have all
construed Whren to require only that the police have reasonable
suspicion to believe that a traffic law has been broken.")
(internal quotation marks omitted) (citation omitted). See also
Berkemer, 468 U.S. at 439 ("the usual traffic stop is more
analogous to a so-called 'Terry stop' than to a formal arrest");

6
In at least some circumstances, reasonable suspicion that
a non-traffic-related law has been broken may also justify a
traffic stop. Cf. State v. Harris, 206 Wis. 2d 243, 258-61, 557
N.W.2d 245 (1996).

13
 No. 2013AP1581-CR

United States v. Ruiz, 785 F.3d 1134, 1141 (7th Cir. 2015);
United States v. Lopez-Soto, 205 F.3d 1101, 1104-05 (9th Cir.
2000) (collecting cases). As the Supreme Court has noted,
"detention of a motorist pursuant to a traffic stop is
presumptively temporary and brief." Berkemer, 468 U.S. at 437.
When weighed against the public interest in safe roads, we are
satisfied that the "temporary and brief" detention of a traffic
stop is an "appropriate manner" in which a police officer may
"approach a person for purposes of investigating possibly
criminal behavior even though there is no probable cause to make
an arrest." Terry, 392 U.S. at 22.
B. Reasonable Mistakes of Law

¶31 At issue in this case is whether a seizure predicated
by an objectively reasonable mistake of law violates
constitutional protections against unreasonable searches and
seizures. The Fourth Amendment to the United States
Constitution and Article I, Section 11 of the Wisconsin
Constitution provide these protections.7 The "[t]emporary
detention of individuals during the stop of an automobile by the
police, even if only for a brief period and for a limited

7
The Fourth Amendment to the United States Constitution
provides: "The right of the people to be secure in their
persons, houses, papers, and effects, against unreasonable
searches and seizures, shall not be violated . . . ." U.S.
Const. amend. IV. Article I, Section 11 of the Wisconsin
Constitution uses identical language. See Wis. Const. Art. I,
§ 11. We have historically read these provisions as
coextensive. State v. Artic, 2010 WI 83, ¶28, 327 Wis. 2d 392,
786 N.W.2d 430.

14
 No. 2013AP1581-CR

purpose, constitutes a 'seizure' of 'persons' within the
meaning" of the Fourth Amendment. Whren, 517 U.S. at 809-10.
See also Popke, 317 Wis. 2d 118, ¶11.
¶32 In the past, Wisconsin courts have held that a seizure
predicated on a police officer's mistake of law is invalid under
the Fourth Amendment. See State v. Brown, 2014 WI 69, ¶22, 355
Wis. 2d 668, 850 N.W.2d 66; Longcore, 226 Wis. 2d at 3-4.
However, the Supreme Court's recent decision in Heien is at odds
with these holdings.
¶33 A brief review of the relevant case law is useful to
provide context for our decision.
¶34 In 1999, the court of appeals issued its opinion in

Longcore. Longcore involved police officer Kevin Larson, who
became suspicious of a vehicle when he observed it leaving the
parking lot of several closed businesses at about 2:00 a.m.
Longcore, 226 Wis. 2d at 4. Officer Larson also observed that
the rear passenger window of the vehicle was missing and had
been replaced with a plastic sheet. Id. Officer Larson
believed the plastic sheet violated Wis. Stat. § 347.43(1),
which required that safety glass be properly equipped in all
cars manufactured after 1935. Id. After pulling the car over,
Officer Larson discovered that the driver of the car, Michael
Longcore, was operating with a suspended license. Id. at 3.
¶35 The circuit court concluded that the stop was valid,
reasoning, "[T]he officer believed a traffic regulation was
being violated, the regulation is ambiguous, the officer's
interpretation was reasonable and therefore his suspicion that
15
 No. 2013AP1581-CR

the law was violated was reasonable." Id. at 5. However, the
court of appeals reversed the circuit court. The court of
appeals stated:

If the facts would support a violation only under a
legal misinterpretation, no violation has occurred,
and thus by definition there can be no probable cause
that a violation has occurred. We conclude that when
an officer relates the facts to a specific offense, it
must indeed be an offense; a lawful stop cannot be
predicated upon a mistake of law.
Id. at 9.
¶36 Longcore was affirmed by this court in a per curiam
opinion after the court divided 3-3 on whether to affirm or
reverse the court of appeals. State v. Longcore, 2000 WI 23,
233 Wis. 2d 278, 607 N.W.2d 620.

¶37 This court was confronted with a similar scenario 14
years later in Brown. On the night of July 3, 2010, Antonio
Brown and a friend attended a barbeque together. Brown, 355
Wis. 2d 668, ¶8. After the barbeque, the friend drove Brown
home in Brown's car because Brown was too intoxicated to drive
himself. Id. The two were stopped by Milwaukee police officers

William Feely and Michael Wawrzonek, who believed that an unlit
bulb in the car's tail lamp violated Wis. Stat. § 347.13(1).
Id., ¶¶2, 7. The officers eventually conducted a search of the
vehicle, which revealed a firearm under the front seat. Id.,
¶7.
¶38 Brown sought to suppress the evidence, arguing that
the stop of his car was unconstitutional and the subsequent
search was therefore invalid. See id., ¶12. The court of

16
 No. 2013AP1581-CR

appeals held that the police lacked probable cause or reasonable
suspicion to stop Brown's vehicle, and because there was no
probable cause or reasonable suspicion to support the stop, the
evidence from the search should have been suppressed. Id.,
¶¶14-16.
¶39 This court affirmed the court of appeals. The
majority opinion noted that prior holdings provided "if the
officers' interpretation of the law were incorrect . . . the
stop would be unconstitutional because a lawful stop cannot be
predicated upon a mistake of law." Id., ¶22 (citing Longcore,
226 Wis. 2d at 9). In examining the relevant statutes, the
court determined that Wis. Stat. § 347.13(1) did not require

every single light bulb in a vehicle's tail lights to work.
Id., ¶3. Rather, the statute required only that the tail lights
"be in proper working condition" and visible from 500 feet away
in the dark. Id. Thus, "[b]ecause having one unlit bulb on the
back of a vehicle does not on its own violate the statutory
requirements for tail lamps, the State . . . failed to show that
the officers had probable cause to believe that a traffic
violation had occurred." Id., ¶38.
¶40 In dissent, Justice Roggensack——joined by Justice
Ziegler——argued that a search based on a reasonable mistake of
law is constitutional. Id., ¶91 (Roggensack, J., dissenting).
Specifically, an officer's mistake of law is reasonable if a
statute is "ambiguous or unclear so that an objectively
reasonable officer could form a reasonable belief that a
violation was occurring, even when it was not." Id.
17
 No. 2013AP1581-CR

¶41 Shortly after Brown, the Supreme Court also considered
the issue of a seizure premised on a police officer's mistake of
law. On the morning of April 29, 2009, a police sergeant began
to follow a vehicle after noticing that the driver looked "very
stiff and nervous." Heien, 135 S. Ct. at 534. When the vehicle
braked, the sergeant noticed that one of the vehicle's brake
lights was not working and he stopped the vehicle. Id. While
issuing a written warning for the broken brake light, the
sergeant became suspicious of the behavior of the occupants and
their conflicting answers to questions he asked. Id. The
sergeant asked for and received consent to search the vehicle,
whereupon he discovered a bag containing cocaine. Id. Heien

was arrested and charged with attempted trafficking in cocaine.
Id. at 535-36.
¶42 As it turned out, having only one functioning brake
light is not a violation of law in North Carolina. Id. at 536.
Thus, on appeal, the Supreme Court had to determine whether the
sergeant's mistake of law nevertheless could have provided "the
reasonable suspicion necessary to uphold the seizure under the
Fourth Amendment." Id. at 534.
¶43 The Court began its decision by noting that under the
Fourth Amendment:

a search or seizure may be permissible even though the
justification for the action includes a reasonable
factual mistake. An officer might, for example, stop
a motorist for traveling alone in a high-occupancy
vehicle lane, only to discover upon approaching the
car that two children are slumped over asleep in the

18
 No. 2013AP1581-CR

back seat. The driver has not violated the law, but
neither has the officer violated the Fourth Amendment.
Id.
¶44 The Court held that an objectively reasonable mistake
of law could give rise to reasonable suspicion. "Because the
officer's mistake about the brake-light law was reasonable, the
stop . . . was lawful under the Fourth Amendment." Id. In
support of this holding, the Court noted, "To be reasonable is
not to be perfect, and so the Fourth Amendment allows for some

mistakes on the part of government officials, giving them fair
leeway for enforcing the law in the community's protection."
Id. at 536.
¶45 The Court further explained:

Reasonable suspicion arises from the combination of an
officer's understanding of the facts and his
understanding of the relevant law. The officer may be
reasonably mistaken on either ground. Whether the
facts turn out to be not what was thought, or the law
turns out to be not what was thought, the result is
the same: the facts are outside the scope of the law.
There is no reason, under the text of the Fourth
Amendment or our precedents, why this same result
should be acceptable when reached by way of a
reasonable mistake of fact, but not when reached by
way of a similarly reasonable mistake of law.
Id.
¶46 Thus, under Heien, a seizure predicated on reasonable
suspicion based on a law enforcement officer's objectively
reasonable mistake of law is not a violation of an individual's
Fourth Amendment rights. This holding, however, stands in stark

contrast to the precedents established in Longcore and Brown.
We therefore must determine which rule controls.

19
 No. 2013AP1581-CR

¶47 The majority opinion in Brown noted that the parties
in that case agreed that a traffic stop predicated on a mistake
of law was unconstitutional. Brown, 355 Wis. 2d 668, ¶22. This
agreement between the parties was based on their common
understanding that Longcore was the settled and accepted law of
Wisconsin. Id. As noted above, the court of appeals in
Longcore "conclude[d] that when an officer relates the facts to
a specific offense, it must indeed be an offense; a lawful stop
cannot be predicated upon a mistake of law." Longcore, 226
Wis. 2d at 9. However, the court of appeals provided no
authority for this proposition.
¶48 The majority opinion in Brown also cited to a number

of federal circuit courts that have held that a mistake of law
cannot provide the basis for a traffic stop. Brown, 355
Wis. 2d 668, ¶23. While those cases undoubtedly provided
persuasive authority at the time Brown was decided, the Supreme
Court's decision in Heien abrogated those cases which were based
on the Fourth Amendment, as the Supreme Court has the final say
on the meaning of the Fourth Amendment.
¶49 Of course, it is uncontested that a state's
constitution may provide citizens with protections beyond those
afforded by the United States Constitution. However, we have
traditionally understood the Wisconsin Constitution's provision
on search and seizure to be coextensive with the Fourth
Amendment. State v. Artic, 2010 WI 83, ¶28, 327 Wis. 2d 392,
786 N.W.2d 430.

20
 No. 2013AP1581-CR

¶50 "Where . . . the language of the provision in the
state constitution is 'virtually identical' to that of the
federal provision . . . , Wisconsin courts have normally
construed the state constitution consistent with the United
States Supreme Court's construction of the federal
constitution." State v. Agnello, 226 Wis. 2d 164, 180-81, 593
N.W.2d 427 (1999) (citing State v. Tompkins, 144 Wis. 2d 116,
133, 423 N.W.2d 823 (1988)). Here, the relevant portions of the
federal and state constitutions are "virtually identical."
Compare U.S. Const. amend. IV with Wis. Const. art. I, § 11.
Accordingly, our standard practice dictates that we interpret
the search and seizure provision of the Wisconsin Constitution

consistently with the search and seizure provision of the United
States Constitution.
¶51 We are sensitive to the fact that Brown was decided
only one year ago. It is unusual for this court to overrule a
holding after such a short period of time. However, it would be
equally unusual for this court to ignore a holding of the
Supreme Court that interprets a provision of the United States
Constitution virtually identical to a provision in the Wisconsin
Constitution.
¶52 Accordingly, we hold that an objectively reasonable
mistake of law by a police officer can form the basis for
reasonable suspicion to conduct a traffic stop. All Wisconsin
cases holding otherwise are hereby overruled to the extent they
conflict with this holding.
C. Pertinent Statutes
21
 No. 2013AP1581-CR

¶53 Before analyzing the case at hand, we consider the
statutes that formed the basis for Officer Price's stop of
Houghton. For Officer Price's interpretation of these statutes
to be "objectively reasonable," we must first consider their
meaning.
¶54 Our purpose in interpreting a statute is to "determine
what the statute means so that it may be given its full, proper,
and intended effect." State ex rel. Kalal v. Circuit Ct. for
Dane Cnty., 2004 WI 58, ¶44, 271 Wis. 2d 633, 681 N.W.2d 110.
To do this, we begin with the language of the statute, giving
words their "common, ordinary, and accepted meaning"; technical
words are given their technical or special definitional meaning.

Id., ¶45. We then consider that language in light of the
statute's structure and context as well as in "relation to the
language of surrounding or closely-related statutes . . . to
avoid absurd or unreasonable results." Id., ¶46. See Force ex
rel. Welcenbach v. Am. Family Mut. Ins. Co., 2014 WI 82, ¶30,
356 Wis. 2d 582, 850 N.W.2d 866. A statute's "context" includes
its statutory history, which "encompasses previously enacted and
repealed provisions of [the] statute." Richards v. Badger Mut.
Ins. Co., 2008 WI 52, ¶22, 309 Wis. 2d 541, 749 N.W.2d 581.
¶55 "If this process of analysis yields a plain, clear
statutory meaning . . . the statute is applied according to this
ascertainment of its meaning." Kalal, 271 Wis. 2d 633, ¶46
(quoting Bruno v. Milwaukee Cnty., 2003 WI 28, ¶20, 260
Wis. 2d 633, 660 N.W.2d 656). However, if the meaning of the
statute is unclear after examining the statute's language, we
22
 No. 2013AP1581-CR

will consult extrinsic sources, including items of legislative
history, to resolve any ambiguities. Id., ¶50.
¶56 The Wisconsin Statutes contain a tremendous number of
provisions directed toward safety on the roadway. At the fore
in this case are statutory sections related to Wisconsin's
unobstructed windshield requirement, set forth in Wis. Stat.
§ 346.88, that motorists have a clear view of the roadway when
operating a vehicle. At issue in this case are subsections
346.88(3)(a) and (3)(b). These sections provide:

(3)(a) No person shall drive any motor vehicle
with any sign, poster or other nontransparent material
upon the front windshield, front side wings, side
windows in the driver's compartment or rear window of
such vehicle other than a certificate or other sticker
issued by order of a governmental agency. Such
permitted sticker shall not cover more than 15 square
inches of glass surface and shall be placed in the
lower left-hand corner of the windshield; the left
corner being on the driver's left when seated behind
the wheel.

(b) No person shall drive any motor vehicle upon
a highway with any object so placed or suspended in or
upon the vehicle so as to obstruct the driver's clear
view through the front windshield.
¶57 The first thing we note about these provisions is that
each provision has a slightly different character. Subsection
(3)(a) appears to be an absolute prohibition on the placement of
"any sign, poster or other nontransparent material upon the
front windshield, front side wings, side windows in the driver's

compartment or rear window of" a vehicle, with a small exception
for government certificates or stickers. Subsection (3)(b), on
the other hand, forbids the placement of all items if they would

23
 No. 2013AP1581-CR

"obstruct the driver's clear view through the front windshield."
In other words, subsection (3)(a) appears to be a strict
prohibition on a narrow group of items, while subsection (3)(b)
is a slightly more forgiving prohibition that applies to all
items.
¶58 The State urges this court to adopt a reading of these
subsections that a driver may have nothing attached to or
suspended from the front windshield——including the rearview
mirror——except those items specifically exempted in subsection
(3)(a). The State made clear at oral argument that this
prohibition would apply to oil change stickers and rosaries as
well as standard pine-tree-shaped air fresheners.8
¶59 We note that the interpretation of these subsections
is a close case. In truth, however, we are unpersuaded that the
purpose of subsections (3)(a) and (3)(b) is to create an
absolute prohibition on any items being attached to or suspended
from a vehicle's front windshield or rearview mirror.
¶60 Subsection (3)(a) creates an absolute prohibition on
"any sign, poster or other nontransparent material upon the

8
"Little Trees" air fresheners have been sold in the United
States since the mid-1950s. The air fresheners were created by
German-Jewish chemist Julius Samaan, who fled the Nazis for
North America before developing his product. The Car-Freshener
Corporation of Watertown, New York, now offers Little Trees air
fresheners in some 60 scents. Car-Freshener Corporation's
president claims the company has sold "billions" of air
fresheners in its history. See generally Hilary Greenbaum and
Dana Rubenstein, Who Made That? (Little Trees), New York Times
Magazine, 19 (Mar. 4, 2012).

24
 No. 2013AP1581-CR

front windshield . . . ." By contrast, another provision of the
same statute, subsection (4), states: "The windshield, side
wings and side and rear windows of a motor vehicle shall be kept
reasonably clean at all times." (Emphasis added.) We see no
reason why the legislature would choose to ban oil change
stickers, often no more than one or two square inches in size
and placed in a top corner of a windshield, but require that
same area of a windshield be only "reasonably" clean.9 Instead,
we interpret subsection (3)(a) to prohibit the attachment of
"sign[s], poster[s]," and other items of a similar nature to the

9
At the motion hearing, the circuit court briefly examined
Officer Price about the area of the windshield that is within
reach of the wipers. The court noted that "manufacturers
determine the area, that is the area that's critical for the
operation of a motor vehicle as determined by the
manufacturers." The court asked Officer Price whether it would
be reasonable to define an obstruction as something that
obstructs the area within the extent of wiper coverage.

Officer Price did not specifically answer the question, but
the question itself raises its own interesting questions. For
example, what if the area of the windshield beyond the range of
the wipers is entirely covered with snow? Under the State's
argument, the presence of the snow may not be a violation.
However, if the driver were to stop and clean the entire
windshield——thereby exposing a one-inch by two-inch oil change
sticker——the driver may then be subject to a ticket, even though
the driver's view would be significantly less obstructed than it
would have been had the driver not cleaned away the snow.

25
 No. 2013AP1581-CR

front windshield of a motor vehicle.10 See State v. Engler, 80
Wis. 2d 402, 408-09, 259 N.W.2d 97 (1977) ("The doctrine of
ejusdem generis . . . provides that when a general word is used
in a statute, either preceded or followed by specific words in
an enumeration, the general word is construed to embrace
something similar to the specific word.").
¶61 Unlike subsection (3)(a), subsection (3)(b) applies to
"any object" in or on a vehicle. However, an object is
prohibited only if it "obstruct[s] the driver's clear view
through the front windshield." The key term in this provision——
"obstruct"——is not defined by the statutory scheme. As such, we
give the term its "common, ordinary, and accepted meaning."

Kalal, 271 Wis. 2d 633, ¶45.
¶62 Black's Law Dictionary defines "obstruct" as "To block
or stop up . . . to close up or close off, esp. by
obstacle . . . . To make difficult or impossible; to keep from
happening; hinder . . . . To cut off a line of vision; to shut
out . . . ." Black's Law Dictionary 1246 (10th ed. 2014)

10
At oral argument, the State was asked about the legality
of a plastic I-Pass prepaid toll collection transponder attached
to a front windshield. The State postulated that an I-Pass
transponder would be exempt from Wis. Stat. § 346.88(3)(a) for
two reasons: because it can be affixed behind the rearview
mirror, and because it is issued by a government agency.
However, subsection (3)(a) exempts only certificates and
stickers issued by a government agency, and makes no exemption
for any otherwise-prohibited item that is placed behind the
rearview mirror. Thus, we fail to see how the State's strict
reading of the statute would not also outlaw the use of an I-
Pass transponder.

26
 No. 2013AP1581-CR

(emphasis added). This definition suggests that an object needs
to have more than a de minimus effect on the driver's vision to
be considered an "obstruction" of a driver's clear view.
¶63 Although there appears to be no published case law
directly on point, Walker v. Baker, 13 Wis. 2d 637, 109
N.W.2d 499 (1961), indirectly supports this position. Walker
was a tort case in which the defendant, Baker, was found liable
for Walker's injuries incurred in an automobile accident. At
trial, the circuit court denied Baker's request to include a
jury instruction for plaintiff's negligence related to Walker's
possibly "obstructed view through his windshield." Id. at 643-
44. This court noted:

While there is testimony that Walker had a pair
of plastic dice suspended over his windshield, there
is no evidence that this interfered with his vision,
and it would be pure speculation on the part of the
jury so to find. The trial court properly refused to
submit the requested instruction as to this aspect of
the case.
Id. at 644.
¶64 It seems likely that, had Walker's "plastic dice

suspended over his windshield" been a violation of Wis. Stat.
§ 346.88,11 a jury instruction would have been in order.
¶65 Given the above, we conclude that Wis. Stat.
§ 346.88(3)(b)——which requires that an object "obstruct" a

11
Wisconsin Stat. § 346.88 has not changed since there was
a comprehensive revision of the motor vehicle code in 1957. See
Chapter 260, Laws of 1957. In fact, much of the language in
§ 346.88 is unchanged since 1929. See §§ 85.35(1) and (3), 1929
Statutes.

27
 No. 2013AP1581-CR

driver's clear view to be a violation——does not mean that every
object in a driver's clear view is a violation. Rather, we
interpret subsection (3)(b) as requiring a material obstruction—
—even if minor——in order to be considered a violation of the
statute.
D. Analysis
¶66 Having concluded both that reasonable suspicion can
form the basis for any traffic stop and that an officer can form
reasonable suspicion to initiate a traffic stop based on an
objectively reasonable mistake of law, and having addressed the
statutory sections at issue in this case, we turn to the
ultimate question of whether Officer Price's initiation of a

traffic stop against Houghton violated Houghton's constitutional
rights.
¶67 The State contends that Officer Price's stop of
Houghton was not based on a mistake of law because the presence
of the GPS unit and air freshener in Houghton's front windshield
was indeed a violation of Wis. Stat. § 346.88. The State argues
in the alternative that any mistake of law by Officer Price as
to whether those items violated the statute was objectively
reasonable. Houghton counters that it was not objectively
reasonable for Officer Price to interpret the statute as
carrying an absolute prohibition on all items in the front
windshield, pointing to Justice Kagan's concurrence in Heien——
joined by Justice Ginsburg——in which she stated that
objectively reasonable mistakes of law are "exceedingly rare."
Heien, 135 S. Ct. at 541 (Kagan, J., concurring).
28
 No. 2013AP1581-CR

¶68 Justice Kagan's concurrence also expanded on what
could constitute an objectively reasonable mistake of law:

A court tasked with deciding whether an officer's
mistake of law can support a seizure thus faces a
straightforward question of statutory construction.
If the statute is genuinely ambiguous, such that
overturning the officer's judgment requires hard
interpretive work, then the officer has made a
reasonable mistake. But if not, not. As the
Solicitor General made the point at oral argument, the
statute must pose a "really difficult" or "very hard
question of statutory interpretation."
Id.
¶69 Justice Kagan noted that the difference between a
"stop lamp" and a "rear lamp" in the North Carolina statute
offered "conflicting signals" as to how the statute should be
interpreted. Id. at 541-42. She concluded that the sergeant's
interpretation of the statute was objectively reasonable because
the sergeant's "judgment, although overturned, had much to
recommend it." Id. at 542.
¶70 Here, we conclude that Officer Price's interpretation
of Wis. Stat. § 346.88——that the statute prohibited the
placement of any object in the front windshield——was objectively
reasonable. That the statute has never been interpreted before

29
 No. 2013AP1581-CR

weighs in favor of this decision.12 See id. at 540 (majority
opinion) ("This 'stop lamp' provision, moreover, had never been
previously construed by North Carolina's appellate courts.").
Our conclusion that the analysis of the statute is a close call
also advances this conclusion. See id. at 542 (Kagan, J.,
concurring) ("The critical point is that the statute poses a
quite difficult question of interpretation . . . .").
¶71 Because "a reasonable judge could agree with the
officer's view" in this case, id. at 541, we hold that Officer
Price's mistake of law was objectively reasonable, and that the
stop of Houghton's vehicle therefore was not unlawful.
¶72 We turn briefly to the issue of Houghton's "missing"

front license plate. Although the State concedes that Officer
Price's interpretation of the license plate statute was not
objectively reasonable, we choose to address this issue to

12
We note that some unpublished Wisconsin cases have found
reasonable suspicion or probable cause of a violation of
subsection (3)(b) based on items hanging from a rearview mirror.
E.g., State v. Currie, No. 2011AP322-CR, unpublished slip op.,
¶2 (Wis. Ct. App. Jul. 19, 2011) ("a very large air freshener");
State v. Jury, No. 2010AP622-CR, unpublished slip op., ¶7 (Wis.
Ct. App. Sept. 1, 2010) (necklace visible "from a distance of
200 feet"); State v. Avery, No. 2001AP1995-CR, ¶4 (Wis. Ct. App.
Feb. 13, 2002) ("a bunch of stuff hanging from the rearview
mirror"). We cite these cases not for any persuasive authority,
but merely to show that the issue of windshield obstruction does
arise in Wisconsin from time to time.

In any event, none of these cases suggest either way
whether subsection (3)(b) is an absolute prohibition on all
items placed in a front windshield.

30
 No. 2013AP1581-CR

provide guidance in future cases and because it was the basis of
the circuit court's decision.
¶73 It is clear that Wis. Stat. § 341.15 requires a
vehicle to display a front license plate only when two license
plates are issued for that vehicle. Officer Price's belief that
Houghton was violating the statute by not having a front plate
was not a reasonable mistake of law to the extent that it
implies that all vehicles must display a front license plate.
¶74 An officer who observes a vehicle driving without a
front license plate may have no way of knowing whether that
vehicle is required to display a front plate. Whether a vehicle
is indeed required to display a front plate is both a question

of law and a question of fact——the operative fact being whether
the vehicle was issued two plates. Thus, it could perhaps be
argued that a stop based on the lack of a front plate when the
vehicle was issued only one plate is based on a mistake of fact
rather than a mistake of law.
¶75 Because searches and seizures can be based on mistakes
of fact, see Illinois v. Rodriguez, 497 U.S. 177, 183-86 (1990);
State v. Reierson, No. 2010AP596-CR, unpublished slip op., ¶1
(Wis. Ct. App. Apr. 28, 2011), we confront the question of
whether the lack of a front license plate, without more, may
give rise to reasonable suspicion to conduct a traffic stop. To
answer this question in the affirmative, we would have to hold
that it is reasonable for a police officer in Wisconsin to
believe that, if a vehicle is operating on a Wisconsin road, it
must have been issued two license plates.
31
 No. 2013AP1581-CR

¶76 Such a belief would usually be unreasonable.
Wisconsin borders four other states, and residents from those
and many other states pass through Wisconsin on a regular basis.
That most vehicles on Wisconsin roads might be registered in
Wisconsin and most vehicles registered in Wisconsin might be
issued two plates is not enough to conclude that a stop of a
vehicle solely because it lacks a front license plate passes
constitutional muster.
¶77 On the other hand, if an officer observes some indicia
that a vehicle without a front license plate is from Wisconsin,
then the officer may indeed have reasonable suspicion to stop
the vehicle. Perhaps the most common indication would be a

Wisconsin plate attached to the rear of the vehicle in question.
However, other things may clue an officer in to a vehicle's
origins as well——for example, markings indicating an affiliation
with a local business.
¶78 Here, however, there was no initial indication that
Houghton's vehicle was from Wisconsin. Once Officer Price was
behind Houghton's vehicle, it would have become apparent from
the rear plate that the vehicle was registered in Michigan.
Thus, to the extent that Officer Price may have believed that
Houghton was violating the law by not having a front license
plate displayed, we hold that belief was neither a reasonable
mistake of law nor a reasonable mistake of fact.

IV. CONCLUSION
¶79 We hold that an officer's reasonable suspicion that a
motorist is violating or has violated a traffic law is
32
 No. 2013AP1581-CR

sufficient for the officer to initiate a stop of the offending
vehicle. We also adopt the Supreme Court's holding in Heien
that an officer's objectively reasonable mistake of law may form
the basis for a finding of reasonable suspicion.
¶80 In this case, we hold that Wis. Stat. § 346.88 does
not create an absolute prohibition on any object being present
in the front windshield of a vehicle. However, Officer Price's
interpretation that the statute did create such a prohibition
was objectively reasonable. Accordingly, Officer Price had
reasonable suspicion to stop Houghton's vehicle, and it was not
error for the circuit court to deny Houghton's motion to
suppress. For these reasons, we reverse the court of appeals.

By the Court.—The decision of the court of appeals is
reversed.

33
 No. 2013AP1581-CR.ssa

¶81 SHIRLEY S. ABRAHAMSON, J. (dissenting). The
majority opinion reverses the decision of the court of appeals
and affirms the defendant's conviction. The conviction was
based on a denial of the defendant's motion to suppress evidence
obtained from a traffic stop. The traffic stop was predicated
on a law enforcement officer's mistake of law, which the
majority opinion deems "objectively reasonable."1
¶82 By declaring for the first time that reasonable

suspicion for a traffic stop can rest on a law enforcement
officer's objectively reasonable mistake of law, the majority
opinion adopts a new interpretation of Article I, Section 11 of
the Wisconsin Constitution. It does so solely in order to
remain in lockstep with the United States Supreme Court's
interpretation of the Fourth Amendment.2

¶83 The majority opinion overturns not only the court of
appeals decision in the instant case but also two prior

decisions: State v. Brown, 2014 WI 69, 355 Wis. 2d 668, 850
N.W.2d 66, and State v. Longcore, 226 Wis. 2d 1, 594 N.W.2d 412
(Ct. App. 1999). What happened to precedent and stare decisis?
¶84 I would adhere to precedent, reaffirm Brown and
Longcore, and affirm the court of appeals decision in the
instant case.

1
Majority op., ¶71.
2
Majority op., ¶¶46-52.

1
 No. 2013AP1581-CR.ssa

¶85 In Brown, an opinion released just last year, this
court held that reasonable suspicion for a traffic stop cannot
rest on a law enforcement officer's mistake of law.3 After Brown
was decided, the United States Supreme Court held in Heien v.
North Carolina, 135 S. Ct. 530 (2014), that under the Fourth
Amendment, a law enforcement officer's reasonable mistake of law
can support reasonable suspicion for a traffic stop.
¶86 The majority opinion in the instant case does an
about-face, adopting the United States Supreme Court's

interpretation of the Fourth Amendment in Heien as the correct

interpretation of the Wisconsin Constitution.
¶87 The drafters of the Wisconsin Constitution could have
simply said "ditto" and incorporated the federal Bill of Rights
into the Wisconsin Constitution. But they did not. Instead,
they adopted a separate and distinct Wisconsin Declaration of
Rights.
¶88 In the instant case and many like it, this court is

doing what the drafters of the Wisconsin Constitution did not
do, namely adopting the federal Bill of Rights. More
specifically, by adopting wholesale the United States Supreme
Court's interpretation of the federal Bill of Rights as the
proper interpretation of Wisconsin's Declaration of Rights, this
court is in effect replacing Wisconsin's Declaration of Rights
with its federal counterpart. This court is not taking

3
State v. Brown, 2014 WI 69, ¶¶22-25, 355 Wis. 2d 668, 850
N.W.2d 66.

2
 No. 2013AP1581-CR.ssa

seriously the Justices' oath of office to support the Wisconsin
Constitution.
¶89 Heien is binding on this court only insofar as the
federal constitution is concerned. It is not binding with
regard to the state constitution. This court need not and
should not automatically adopt the United States Supreme Court's
interpretation of the Fourth Amendment as the proper
interpretation of Article I, Section 11 of the Wisconsin
Constitution.

¶90 In Brown, this court set forth three primary reasons

for its determination that reasonable suspicion cannot rest on a
law enforcement officer's mistake of law:
1. Wisconsin precedent so stated. In State v. Longcore,
226 Wis. 2d 1, 9, 594 N.W.2d 412 (Ct. App. 1999), the
court of appeals declared that "a lawful [traffic]
stop cannot be predicated upon a mistake of law."
2. Other jurisdictions were in accord. A substantial

majority of both the federal circuit courts and the
state courts that had addressed the issue had
concluded that a law enforcement officer's mistake of
law cannot support reasonable suspicion or probable
cause for a traffic stop.4
3. Holding that a law enforcement officer's mistake of
law could support lawful traffic stops would defeat
the purpose of the exclusionary rule. More

4
Brown, 355 Wis. 2d 668, ¶¶23, 25. See also Heien v. North
Carolina, 135 S.Ct. 530, 544 (2014) (Sotomayor, J., dissenting).

3
 No. 2013AP1581-CR.ssa

specifically, declining to exclude evidence that was
gathered from a traffic stop premised on a law
enforcement officer's erroneous view of the law
"would remove the incentive for police to make
certain that they properly understand the law that
they are entrusted to enforce and obey."5
¶91 These considerations remain persuasive and convince me
to adhere to Brown. A law enforcement officer's reasonable
mistake of law cannot, in my view, render a traffic stop

reasonable in the eyes of the Wisconsin Constitution.
¶92 My position is supported by several cogent points that
Justice Sotomayor makes in her dissent in Heien:

1. An inquiry into the reasonableness of officers'
understanding of the law breaks with longstanding
federal and state court precedent.6
2. The notion that the law is definite and knowable sits
at the foundation of our legal system. Yet, Heien

gives those who enforce the law leeway in
interpreting and understanding it.7

5
Brown, 355 Wis. 2d 668, ¶24 (internal quotation marks
omitted).
6
Heien, 135 S. Ct. at 542-43 (Sotomayor, J., dissenting).
7
Id. at 543 (Sotomayor, J., dissenting).

Heien purports to rest on the concept of reasonableness,
the touchstone of the Fourth Amendment. However, as Justice
Sotomayor's dissent explains,

this broad statement simply sets the standard a court
is to apply when it conducts its inquiry into whether
the Fourth Amendment has been violated. It does not
(continued)
4
 No. 2013AP1581-CR.ssa

3. Heien "further erod[es] the Fourth Amendment's
protection of civil liberties in a context," namely
traffic stops, "where that protection has already
been worn down."8
4. Heien is a significant expansion of officers'
authority and leads one to wonder "how a citizen
seeking to be law-abiding and to structure his or her
behavior to avoid these invasive, frightening, and
humiliating encounters could do so."9

5. Because traffic stops can be annoying, frightening
and humiliating, they have consequences for

define the categories of inputs that courts are to
consider when assessing the reasonableness of a search
or seizure, each of which must be independently
justified. What this case requires us to decide is
whether a police officer's understanding of the law is
an input into the reasonableness inquiry, or whether
this inquiry instead takes the law as a given and
assesses an officer's understanding of the facts
against a fixed legal yardstick.

Id. at 542.
8
Heien, 135 S. Ct. at 543 (Sotomayor, J., dissenting).

For discussion of the "wearing down" of the protections of
the Fourth Amendment in Wisconsin courts, see Alan Ball, How
Effective are Fourth-Amendment Arguments in the Wisconsin
Supreme Court?, SCOWstats, June 22, 2015,
http://www.scowstats.com/2015/06/22/how-effective-are-fourth-
amendment-arguments-in-the-wisconsin-supreme-court/ (last
visited June 30, 2015) (reviewing decisions of the Wisconsin
Supreme Court and concluding that the current judicial climate
is inhospitable to Fourth Amendment arguments).
9
Heien, 135 S. Ct. at 544 (Sotomayor, J., dissenting).

5
 No. 2013AP1581-CR.ssa

individuals and communities "and for their
relationships with the police . . . ."10
6. Law enforcement officers have not been unduly
hampered in the exercise of their duties by the rule
that their mistakes of law are not considered as part
of the Fourth Amendment reasonableness inquiry.11
7. There is scarcely any law that does not admit of some
ingenious doubt.12 A decision interpreting a law will
not immunize the law from further interpretation.

Interpretation of the law constitutes a substantial
portion of court business.
¶93 These considerations apply with equal force in the
context of the Wisconsin Constitution. Both precedent and
policy compel me to conclude that a traffic stop premised on a
law enforcement officer's mistake of law is unreasonable and
thus unlawful under Article I, Section 11 of the Wisconsin
Constitution.

¶94 Accordingly, the traffic stop at issue in the instant
case, which was premised on a law enforcement officer's mistake

10
Heien, 135 S. Ct. at 544 (Sotomayor, J., dissenting).
11
Id.
12
Id. Justice Kagan authored a concurrence in Heien
explaining that an officer has made a reasonable mistake of law
only when the statute in question is "genuinely ambiguous,"
"requires hard interpretive work," and "poses a quite difficult
question." Heien, 135 S. Ct. at 541-42 (Kagan, J., concurring).
I do not think the mistake of law at issue in the instant case
falls within this exacting interpretation of what constitutes a
reasonable mistake of law.

6
 No. 2013AP1581-CR.ssa

of law, was unlawful. The defendant's motion to suppress the
evidence obtained from the unlawful traffic stop should have
been granted, and the defendant's conviction should be reversed.
¶95 For the reasons set forth, I dissent.
¶96 I am authorized to state that Justice ANN WALSH
BRADLEY joins this opinion.

7
 No. 2013AP1581-CR.ssa

1