2014 WI 69

SUPREME COURT OF WISCONSIN

CASE NO.: 2011AP2907-CR 

COMPLETE TITLE: State of Wisconsin,

 Plaintiff-Respondent-Petitioner,

 v.

Antonio D. Brown,

 Defendant-Appellant. 

REVIEW OF A DECISION OF THE COURT OF APPEALS

346 Wis. 2d 98, 827 N.W.2d 903

(Ct. App. 2013 – Published)

PDC No: 2013 WI App 17

OPINION FILED: July 16, 2014

SUBMITTED ON BRIEFS: 

ORAL ARGUMENT: January 15, 2014 

SOURCE OF APPEAL:

COURT: Circuit 

COUNTY: Milwaukee

JUDGE: Rebecca F. Dallet

JUSTICES:

CONCURRED: 

DISSENTED: PROSSER, J., dissents. (Opinion filed.)

ROGGENSACK, ZIEGLER, JJ., dissent. (Opinion 

filed.) 

NOT PARTICIPATING: 

ATTORNEYS:

For the plaintiff-respondent-petitioner, the cause was 

argued by Aaron O’Neil, assistant attorney general, with whom on 

the briefs was J.B. Van Hollen, attorney general.

For the defendant-appellant, there were briefs by Hannah B. 

Schieber, assistant state public defender, and oral argument by 

Hannah B. Schieber.
2

An amicus curiae brief was filed by Ellen Henak and Henak 

Law Office, S.C., Milwaukee, on behalf of the Wisconsin 

Association of Criminal Defense Lawyers. 
2014 WI 69

NOTICE

This opinion is subject to further 

editing and modification. The final 

version will appear in the bound 

volume of the official reports. 

No. 2011AP2907-CR

(L.C. No. 2010CF3318)

STATE OF WISCONSIN : IN SUPREME COURT

State of Wisconsin,

 Plaintiff-Respondent-Petitioner,

 v.

Antonio D. Brown,

 Defendant-Appellant.

FILED

JUL 16, 2014

Diane M. Fremgen

Clerk of Supreme Court

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

¶1 ANN WALSH BRADLEY, J. The State of Wisconsin seeks 

review of a published decision of the court of appeals1 that 

reversed the circuit court's denial of Antonio Brown's motion to 

vacate his conviction and plea and to suppress all evidence 

seized during a stop of his vehicle. The court of appeals 

determined that the circuit court erred because there was no 

probable cause or reasonable suspicion to stop Brown's vehicle. 

 

1 State v. Brown, 2013 WI App 17, 346 Wis. 2d 98, 827 N.W.2d 

903 (reversing order of the circuit court for Milwaukee County, 

Rebecca F. Dallet, J.).
No. 2011AP2907-CR 

2

Accordingly, it concluded that the evidence resulting from the 

search should have been suppressed. 

¶2 The State contends that the officers' observation of 

an unlit light bulb in Brown's tail lamp justified a stop 

because the law requires all light bulbs in a tail lamp to be 

lit. It asserts that this requirement is found in Wis. Stat. 

§ 347.13(1) (2009-10),2 which prohibits the operation of a 

vehicle at night unless its tail lamps are in "good working 

order." Because the officers observed a violation of the law, 

the State maintains that they had probable cause to stop the 

vehicle. Even if the unlit bulb was not part of the tail lamp, 

the State contends that it still created reasonable suspicion to 

stop the vehicle and the results of the search should not be 

suppressed.

¶3 Contrary to the State, we do not interpret Wis. Stat. 

§ 347.13(1) as requiring every single light bulb in a tail lamp 

to be lit. The plain language of the statute requires that a 

tail lamp emit a red light visible from 500 feet behind the 

vehicle during hours of darkness. This interpretation is 

further supported by related statutes requiring that the lamps 

be in proper working condition. Wis. Stat. § 347.06(3).

¶4 Because the only basis for the stop of Brown's vehicle 

was the unlit bulb, we conclude that there was not probable 

cause or reasonable suspicion to stop the vehicle. Where the 

stop of the vehicle was unlawful, so too was its search, and the 

 

2

All subsequent references to the Wisconsin Statutes are to 

the 2009-10 version unless otherwise indicated.
No. 2011AP2907-CR 

3

results of that search must be suppressed. Accordingly, we 

affirm the court of appeals.

I

¶5 It is uncontested that Brown was a passenger in a 

Buick Electra that was stopped by police officers. During the 

stop, the officers searched the vehicle and discovered a gun. 

Brown was charged with possession of a firearm by a felon, in 

violation of Wis. Stat. § 941.29(2). He subsequently filed a 

motion to suppress the gun, asserting that the officers lacked 

reasonable suspicion or probable cause to stop the vehicle.

¶6 At the motion hearing the State presented the 

testimony of Officer Wawrzonek and Officer Feely. Although some 

details varied, the officers' testimony regarding the stop of 

Brown's vehicle was largely consistent. 

¶7 According to the officers, they were on a routine 

patrol when they spotted a 1977 Buick Electra with a "defective 

tail light." Officer Wawrzonek explained that there was a "wide 

band" with three light panels on the back of the vehicle and one 

of the panels was out. Officer Feely stated that it was the 

middle light on the driver's side that was out. Based on the 

Buick's "defective" tail lamp, Officer Feely activated the 

flashing red and blue lights on their patrol car and conducted a 

traffic stop. After stopping the vehicle and removing its 

passengers, Officer Feely searched the vehicle and discovered a 

firearm under the front passenger-side seat.

¶8 Brown presented the testimony of Willie Lipsey who 

stated that on the night of the stop he attended a barbeque with 
No. 2011AP2907-CR 

4

Brown. When they left, Lipsey drove Brown's car because Brown 

was intoxicated. Lipsey testified that he stopped at a gas 

station and observed that the tail lamps were functioning 

properly when he pumped gas into the car. He was in a position 

to see this as the gas tank of the Buick is behind the rear 

license plate. After leaving the gas station, Lipsey headed 

home. The stop occurred as he was parking.

¶9 Several photographs of the back of Brown's vehicle 

were admitted into evidence. One photograph is a close-up view 

of the rear-passenger side of the vehicle with the outside panel 

encasing the tail lamp removed. Four light bulbs are visible: a 

cluster of three bulbs on the left-hand side and a fourth bulb 

toward the center of the vehicle next to its license plate. In 

explaining the photo, Lipsey testified that the first and third 

lights were tail lights, the second light was a brake light, and 

the separate light was a reverse light. According to Lipsey, 

only the two tail lights are lit when the car is driving down 

the street. 

¶10 The circuit court denied the suppression motion. It 

determined that Lipsey's testimony that the tail lights were 

working was not credible. In contrast, it found the officers' 

testimony to be credible and therefore determined that there was 

probable cause for the stop. It further determined that the 

search was justified by the need to protect the officers' 

safety. 
No. 2011AP2907-CR 

5

¶11 Following the ruling, Brown pled guilty to the charge.3 

Subsequently, the court sentenced Brown to five years 

imprisonment with three years initial confinement and two years 

extended supervision. 

¶12 Brown submitted a motion for postconviction relief 

seeking an order vacating his conviction and guilty plea and 

suppressing all evidence seized during the stop of the Buick. 

Citing Wis. Stat. § 347.13(1), he asserted that there was no 

basis for the stop because under the law only two tail lamps 

must be in good working order, not all of four of them. 

Accordingly, he contended that the stop of the Buick was 

unconstitutional and evidence found during its search must be 

suppressed.4 

¶13 The circuit court denied the postconviction motion. 

It determined that the officers had a reasonable belief that one 

of the vehicle's tail lamps was defective. Even if the officers 

 

3 Although a guilty plea generally waives all 

nonjurisdictional defects and defenses, there is an exception 

which permits appellate review of orders denying motions to 

suppress evidence. Wis. Stat. § 971.31(10); Cnty. of Racine v. 

Smith, 122 Wis. 2d 431, 434-35, 362 N.W.2d 439 (Ct. App. 1984).

4 In the alternative, Brown argued to the circuit court that 

he was denied effective assistance of counsel because his trial 

attorney failed to bring Wis. Stat. § 347.13(1) to the court's 

attention. The court concluded that this argument was 

unconvincing because it did not agree with Brown's 

interpretation of Wis. Stat. §347.13(1). Brown's motion also 

requested an order amending the judgment of conviction to 

include 209 days of sentence credit for the time he spent in 

jail between the date of his arrest and the date of his 

sentencing. The court determined that Brown was entitled to 195 

days, not 209 days of sentence credit.
No. 2011AP2907-CR 

6

were wrong, the court stated, that did not affect their 

reasonable belief at the time of the stop. 

¶14 On appeal, Brown again argued that the evidence from 

the search of the vehicle should have been suppressed because 

there was no probable cause or reasonable suspicion for the 

stop. 

¶15 Although a stop can be based on either probable cause 

or reasonable suspicion, the court of appeals determined that 

the issue in this case was whether the unlit bulb created 

probable cause. State v. Brown, 2013 WI App 17, ¶¶14-15, 346 

Wis. 2d 98, 827 N.W.2d 903. It noted the officers' testimony 

that they stopped the vehicle because of the unlit bulb, stating 

"[t]hey did not act upon a suspicion that warranted further 

investigation, but on [their] observation of a violation being 

committed in [their] presence." Id. at ¶15 (quoting State v. 

Longcore, 226 Wis. 2d 1, 8-9, 594 N.W.2d 412 (Ct. App. 1999)). 

Because the officers were not acting on a suspicion, but on what 

they believed was a violation of law being committed in their 

presence, the court concluded that probable cause was the 

appropriate focus. Id. 

¶16 The court of appeals agreed with Brown. Id. at ¶21. 

It reasoned that under Wis. Stat. § 347.13(1) a vehicle's tail 

lamps do not need to be fully lit or in perfect condition in 

order to be in "good working order." Id. Noting that a lawful 

stop cannot be predicated on a mistake of law, the court 

determined that the officers' mistaken belief that all the tail 

lights on a vehicle need to be lit could not serve as probable 
No. 2011AP2907-CR 

7

cause for a stop. Id. (citing Longcore, 226 Wis. 2d at 9). 

Accordingly, it reversed the circuit court.5

II

¶17 In this case we are asked to consider whether Brown's 

vehicle was lawfully stopped.6 "Whether there is probable cause 

or reasonable suspicion to stop a vehicle is a question of 

constitutional fact." State v. Popke, 2009 WI 37, ¶10, 317 Wis. 

2d 118, 765 N.W.2d 569. As such, it is a mixed question of fact 

and law, requiring a two-step standard of review. State v. 

Post, 2007 WI 60, ¶8, 301 Wis. 2d 1, 733 N.W.2d 634. This court 

reviews the circuit court's findings of fact under the clearly 

erroneous standard, and reviews independently the application of 

those facts to constitutional principles. Id. 

¶18 Here, the relevant facts are undisputed. The parties 

agree that the officers stopped Brown's vehicle because one of 

 

5 Because it reversed on the merits, the court of appeals 

did not address Brown's alternative argument that his trial 

counsel was ineffective. Brown, 346 Wis. 2d 98, ¶21 n.6. 

Brown also appealed the issue of his sentence credit. The court

also determined that it did not need to address Brown's 

sentencing credit issue because it reversed his conviction. It 

noted that the State had conceded that had Brown's conviction 

stood, he would have been entitled to the sentence credit he 

sought. Id. at ¶22. For the same reason as the court of 

appeals, we also do not address the issues of ineffective 

assistance of counsel or Brown's sentence credit.

6 When accepting the petition for review, we asked the 

parties to address the propriety of the search in light of 

Arizona v. Gant, 556 U.S. 332 (2009). Both parties 

affirmatively stated that Gant does not apply and that the issue 

in this case is whether the stop itself violated Brown's rights, 

not the subsequent search. Accordingly, we limit our analysis 

to the reasonableness of the stop of Brown's vehicle.
No. 2011AP2907-CR 

8

the three lights on the rear driver's side of the car was not 

lit. Thus, our inquiry focuses on whether under the facts there 

were sufficient grounds for a traffic stop. This inquiry calls 

upon us to interpret the relevant statute establishing the 

requirements for vehicle tail lamps, Wis. Stat. § 347.13(1). 

Statutory interpretation is a question of law that we review 

independently of the decisions rendered by the circuit court and 

the court of appeals. State v. Ziegler, 2012 WI 73, ¶37, 342 

Wis. 2d 256, 816 N.W.2d 238.

III

¶19 We begin our analysis by examining the constitutional 

principles underlying traffic stops. The Fourth Amendment of 

the United States Constitution and Article I, Section 11 of the 

Wisconsin Constitution protect citizens from unreasonable 

searches and seizures.7 Traffic stops are considered seizures 

and thus must be reasonable to pass constitutional muster. 

 

7 The Fourth Amendment of the United States Constitution 

states "[t]he right of the people to be secure in their persons 

. . . against unreasonable searches and seizures, shall not be 

violated, and no Warrants shall issue, but upon probable cause 

. . . ." Likewise, Article I, Section 11 of the Wisconsin 

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; and no warrant 

shall issue but upon probable cause . . . ." 

This court generally interprets the protections against 

unreasonable searches and seizures afforded by the state and 

federal constitutions coextensively. State v. Post, 2007 WI 60, 

¶10 n.2, 301 Wis. 2d 1, 733 N.W.2d 634. "However, the state 

provisions may provide greater protections." Id. (citing State 

v. Eason, 2001 WI 98, ¶63, n.31, 245 Wis. 2d 206, 629 N.W.2d 

625).
No. 2011AP2907-CR 

9

Popke, 317 Wis. 2d 118, ¶11; Whren v. United States, 517 U.S. 

806, 809-10 (1996). If the seizure is unreasonable and 

therefore unconstitutional, then evidence obtained as a result 

is generally inadmissible. State v. Harris, 206 Wis. 2d 243, 

263, 557 N.W.2d 245 (1996). A good faith exception to this rule 

applies in limited circumstances such as where the police have 

relied in good faith on either a warrant issued by a detached 

and neutral magistrate or on well-settled law that was 

subsequently overturned. State v. Dearborn, 2010 WI 84, ¶44, 

327 Wis. 2d 252, 786 N.W.2d 97; State v. Eason, 2001 WI 98, ¶3, 

245 Wis. 2d 206, 629 N.W.2d 625.

¶20 The burden is on the State to prove that a stop meets 

the constitutional reasonableness requirement. Post, 301 Wis. 

2d 1, ¶12; Harris, 206 Wis. 2d at 263. A traffic stop can be 

based on probable cause or reasonable suspicion. State v. 

Gaulrapp, 207 Wis. 2d 600, 605, 558 N.W.2d 696 (Ct. App. 1996)

(citing Whren, 517 U.S. at 809-10; Berkemer v. McCarty, 468 U.S. 

420, 439 (1984)). "[P]robable cause exists when the officer has 

'reasonable grounds to believe that the person is committing or 

has committed a crime.'" Popke, 317 Wis. 2d 118, ¶14 (quoting 

Johnson v. State, 75 Wis. 2d 344, 348, 249 N.W.2d 593 (1977)). 

There is reasonable suspicion justifying a stop if "the facts of 

the case would warrant a reasonable police officer, in light of 

his or her training and experience, to suspect that the 

individual has committed, was committing, or is about to commit 

a crime." Post, 301 Wis. 2d 1, ¶13. 
No. 2011AP2907-CR 

10

¶21 In this case, the officers stopped Brown's vehicle 

because one of the bulbs on the back of the vehicle was unlit. 

The State asserts that the unlit bulb created probable cause to 

stop the vehicle because it violated the requirement in Wis. 

Stat. § 347.13(1) that tail lamps be in "good working order." 

It further contends that even if the officers were wrong and the 

unlit bulb was not part of the tail lamp, the unlit bulb still 

created reasonable suspicion that Wis. Stat. § 347.13(1) was 

being violated. Brown disagrees with both contentions, arguing 

that Wis. Stat. § 347.13(1) does not require all bulbs in a tail 

lamp to be lit and thus the officers had neither probable cause 

nor reasonable suspicion to stop his vehicle. 

¶22 Both parties agree that if the officers' 

interpretation of the law were incorrect that the stop would be 

unconstitutional because a lawful stop cannot be predicated upon 

a mistake of law. Longcore, 226 Wis. 2d at 9. At oral 

argument, the State explicitly stated that "we are not 

challenging Longcore."8 In its supplemental briefing the State 

 

8 At oral argument counsel for the State engaged in the 

following exchange:

Justice Ziegler: Why couldn't [the stop] be based upon 

the officer's reasonable belief that the tail light 

was out? 

Attorney for the State: It could be based on the- if 

the officer could reasonably believe that that bulb 

was part of the tail lamp, and the law requires that 

all the bulbs be lit in the tail lamp, if that's 

correct, then the stop would be valid on the basis ofChief Justice Abrahamson: Even if he's wrong.
No. 2011AP2907-CR 

11

maintained that "the existence of probable cause or reasonable 

suspicion in the context of a traffic stop depends on the 

correct interpretation of the statute prohibiting the conduct." 9

¶23 A substantial majority of the federal circuit courts 

have also held that a lawful stop cannot be predicated upon a 

mistake of law.10 United States v. Williams, 740 F.3d 308, 312

(4th Cir. 2014) ("Nor do we suggest that a police officer's 

mistake of law can support probable cause to conduct a stop when 

the underlying conduct was not, in fact, illegal."); United 

 

Attorney for the State: Even if he's wrong about the 

facts. But if he's wrong about the law, then we are 

conceding that the stop was invalid. 

9 After oral argument this court asked the parties for 

supplemental briefing. Specifically, the court asked the 

parties to brief:

1) whether the officer had reasonable suspicion to stop 

Brown's vehicle because the officer believed that Wis. 

Stat. § 347.13(1) was violated when not all the tail 

light bulbs on Brown's vehicle were working. 

2) whether an officer's good faith mistake of law on which 

the officer makes a traffic stop, requires reviewing 

courts to conclude that the stop was not lawful.

State v. Brown, No. 2011AP2907, unpublished order (Feb. 26, 

2014).

10 Justice Roggensack's dissent advocates a minority 

position. Only three circuit courts have adopted an approach 

which would permit a stop based on an error of law: the D.C. 

Circuit, the Third Circuit, and the Eighth Circuit. See United 

States v. Southerland, 486 F.3d 1355, 1359 (D.C. Cir. 2007); 

United States v. Delfin-Colina, 464 F.3d 392, 399 (3d Cir. 

2006); United States v. Bueno, 443 F.3d 1017, 1024 (8th Cir. 

2006). 
No. 2011AP2907-CR 

12

States v. McDonald, 453 F.3d 958, 962 (7th Cir. 2006)

(determining stop was unreasonable where "even if [the driver]

acted exactly as [the officer] believed, his actions were not a 

violation of any Illinois state traffic law."); United States v. 

Coplin, 463 F.3d 96, 101 (1st Cir. 2006) ("Stops premised on a 

mistake of law, even a reasonable, good-faith mistake, are 

generally held to be unconstitutional."); United States v. 

Tibbetts, 396 F.3d 1132, 1138 (10th Cir. 2005) ("[F]ailure to 

understand the law by the very person charged with enforcing it 

is not objectively reasonable."); United States v. 

Chanthasouxat, 342 F.3d 1271, 1279 (11th Cir. 2003) ("[A]

mistake of law cannot provide reasonable suspicion or probable 

cause to justify a traffic stop."); United States v. Twilley, 

222 F.3d 1092, 1096 (9th Cir. 2000) ("[I]n this circuit, a belief 

based on a misunderstanding of the law cannot constitute the 

reasonable suspicion required for a constitutional traffic 

stop."); United States v. Miller, 146 F.3d 274, 279 (5th Cir. 

1998) ("[G]iven that having a turn signal on is not a violation 

of Texas law, no objective basis for probable cause justified 

the stop of Miller"). 

¶24 As the Seventh Circuit has explained, "[a]n officer 

cannot have a reasonable belief that a violation of the law 

occurred when the acts to which an officer points as supporting 

probable cause are not prohibited by law." McDonald, 453 F.3d 

at 961. The grounds for a traffic stop must be objectively 

reasonable and "[a] stop based on a subjective belief that a law 

has been broken, when no violation actually occurred, is not 
No. 2011AP2907-CR 

13

objectively reasonable." Id. at 962. Admitting evidence into 

the record on such a basis "would defeat the purpose of the 

exclusionary rule, for it would remove the incentive for police 

to make certain that they properly understand the law that they 

are entrusted to enforce and obey." Id. (quoting United States 

v. Lopez-Soto, 205 F.3d 1101, 1106 (9th Cir. 2000)); see also

Wayne A. Logan, Police Mistakes of Law, 61 Emory L.J. 69, 106 

(2011) ("there has been no mistaking that the specter of [the 

exclusionary rule's] application has prompted police departments 

to significantly fortify and improve their training efforts 

relative to Fourth Amendment expectations.").

¶25 Further, the rule that an officer's mistake of law is 

not sufficient grounds for a stop is consistent with holdings 

from a substantial majority of the state courts that have 

addressed the issue. State v. Babcock, 992 N.E.2d 1215, 1220

(Ohio Ct. App. 2013) ("[W]e hold that the exclusionary rule 

operates to bar the admission of evidence obtained as a result 

of a traffic stop based on conduct that a police officer 

mistakenly believes is a violation of the law."); Martin v. Kan. 

Dep't of Revenue, 176 P.3d 938, 948 (Kan. 2008) ("[A] police 

officer must be held to a more demanding standard of legal 

knowledge than any citizen who may be subject to the officer's 

exercise of authority. . . . [C]onsequently [we] hold that an 

officer's mistake of law alone can render a traffic stop 

violative of the Fourth Amendment. . . ."); State v. Tiffin, 121 

P.3d 9, 12 (Or. Ct. App. 2005) ("[T]he facts, as the officer 

perceives them, must actually constitute an infraction in order 
No. 2011AP2907-CR 

14

for the officer's belief that an infraction occurred to be 

objectively reasonable."). See also State v. Cantsee, 321 P.3d 

888, 891 (Nev. 2014); State v. Dunbar, 728 S.E.2d 539, 545 (W. 

Va. 2012); State v. Louwrens, 792 N.W.2d 649, 654 (Iowa 2010); 

McDonald v. State, 947 A.2d 1073, 1079-80 (Del. 2008); State v.

Williams, 185 S.W.3d 311, 319 (Tenn. 2006); State v. Lacasella, 

60 P.3d 975, 981 (Mont. 2002); State v. Lussier, 757 A.2d 1017, 

1029 (Vt. 2000); Commonwealth v. Rachau, 670 A.2d 731, 735 (Pa. 

Commw. Ct. 1996); Commonwealth v. Bernard, 3 N.E.3d 1113, 1115 

n.2 (Mass. App. Ct. 2014); Gilmore v. State, 42 A.3d 123, 135 

(Md. Ct. Spec. App. 2012); Robinson v. State, 377 S.W.3d 712, 

722 (Tex. Crim. App. 2012); J.D.I. v. State, 77 So. 3d 610, 617 

(Ala. Crim. App. 2011); Gunn v. State, 956 N.E.2d 136, 139 

(Ind. Ct. App. 2011); People v. Cole, 874 N.E.2d 81, 88 (Ill. 

App. Ct. 2007); State v. Kilmer, 741 N.W.2d 607, 611 (Minn. Ct. 

App. 2007); People v. Ramirez, 44 Cal. Rptr. 3d 813, 816 (Cal. 

App. 2006); State v. Puzio, 878 A.2d 857, 860 (NJ App. Div. 

2005); Gordon v. State, 901 So. 2d 399, 405 (Fla. Dist. Ct. App. 

2005); Byer v. Jackson, 661 N.Y.S.2d 336, 338 (N.Y. App. Div. 

1997).

11

 

11 We acknowledge that a minority of the state courts that 

have addressed the issue have taken a contrary position. See, 

e.g., State v. Heien, 737 S.E.2d 351 (N.C. 2012); Moore v. 

State, 986 So. 2d 928, 935 (Miss. 2008); Travis v. State, 959 

S.W.2d 32, 34 (Ark. 1998); McConnell v. State, 374 S.E.2d 111, 

113 (Ga. Ct. App. 1988); DeChene v. Smallwood, 311 S.E.2d 749, 

751 (Va. 1984).
No. 2011AP2907-CR 

15

¶26 Having examined the application of constitutional 

principles underlying traffic stops, we turn to address the 

interpretation of Wis. Stat. § 347.13(1) in order to apply those 

principles in this case. Statutory interpretation begins with 

the language of the statute. State ex rel. Kalal v. Circuit 

Court for Dane County, 2004 WI 58, ¶45, 271 Wis. 2d 633, 681 

N.W.2d 110. The language in a statute "is given its common, 

ordinary, and accepted meaning, except that technical or 

specially-defined words or phrases are given their technical or 

special definitional meaning." Id. Further, a statute's 

language is interpreted in the context in which it is used, "in 

relation to the language of surrounding or closely-related 

statutes; and reasonably, to avoid absurd or unreasonable 

results." Id. at ¶46.

¶27 Wisconsin Stat. § 347.13(1) requires a vehicle to have 

at least one tail lamp which emits a red light visible to 

another vehicle traveling 500 feet behind it and prohibits 

operation of a vehicle at night when its tail lamps are not "in 

good working order." Wis. Stat. § 347.13(1). The statute 

provides:

No person shall operate a motor vehicle . . . upon a 

highway during hours of darkness unless such motor 

vehicle . . . is equipped with at least one tail lamp 

mounted on the rear which, when lighted during hours 

of darkness, emits a red light plainly visible from a 

distance of 500 feet to the rear. No tail lamp shall 

have any type of decorative covering that restricts 

the amount of light emitted when the tail lamp is in 

use. No vehicle originally equipped at the time of 

manufacture and sale with 2 tail lamps shall be 
No. 2011AP2907-CR 

16

operated upon a highway during hours of darkness 

unless both such lamps are in good working order. 

Wis. Stat. § 347.13(1) (emphasis supplied). The term "tail 

lamp" is defined as "a device to designate the rear of a vehicle 

by a warning light."

12 Wis. Stat. § 340.01(66). At issue in 

this case is what constitutes a tail lamp in "good working 

order."

¶28 The phrase "good working order" is not defined in the 

statute, thus we accord the phrase its common, ordinary and 

accepted meaning. "In determining the ordinary meaning of 

undefined words, '[w]e may consult a dictionary to aid in 

statutory construction." Xcel Energy Servs. v. Labor & Indus. 

Review Comm'n, 2013 WI 64, ¶30, 349 Wis. 2d 234, 833 N.W.2d 665 

(quoting Cnty. of Dane v. Labor & Indus. Review Comm'n, 2009 WI 

9, ¶23, 315 Wis. 2d 293, 759 N.W.2d 571). 

¶29 Dictionary definitions of "good," "working," and 

"working order" suggest that the term "good working order" means 

suitable or functioning for the intended use.13 Thus, the 

 

12 Because Wis. Stat. § 340.01(66) defines "tail lamp" as "a 

device," it is the entire tail lamp, and not each individual 

light bulb in the tail lamp, that must function as indicated by 

Wis. Stat. § 347.13(1).

13 For definitions of "good" see The American Heritage 

Dictionary of the English Language 780 (3d ed. 1992) ("[s]erving 

the desired purpose or end, suitable"); The Random House 

Unabridged Dictionary 822 (2d ed. 1993) ("satisfactory in 

quality, quantity, or degree"); and Webster's Third New 

International Dictionary 978 (1986) ("adapted to the end 

designed or proposed: satisfactory in performance").
No. 2011AP2907-CR 

17

ordinary meaning of "good working order" focuses on whether an 

object is functioning so as to fulfill its intended purpose. 

¶30 Further, construing "good working order" in the 

context of Wis. Stat. § 347.13(1) to mean functioning for the 

intended purpose is consistent with how we have construed "good 

working order" in the past. 

¶31 In State v. Trailer Service, Inc., 61 Wis. 2d 400, 

404, 212 N.W.2d 683 (1973), the court looked to function when 

determining whether a certified scale for weighing a vehicle was 

in "good working order." The case involved a dispute over 

whether a truck had been properly weighed before its driver was 

given a citation for overload. Id. at 402. The court examined 

two statutes: Wis. Stat. § 348.19(1)(a), permitting an officer 

to require a truck to be weighed on the nearest usable scale, 

and Wis. Stat. § 348.15(5), requiring trucks to be weighed on 

scales that are in "good working order." Id. at 404-05. It 

noted that "'[u]sable' also means 'in good working order,' i.e., 

 

For definitions of "working" see The American Heritage 

Dictionary of the English Language 2057 (3d ed. 1992)

("[o]perating or functioning as required," "[s]ufficient to 

allow action," and "[a]dequate for practical use"); The Random 

House Unabridged Dictionary 2189 (2d ed. 1993) ("operating; 

producing effects, results, etc.," and "adequate for usual or 

customary needs"); and Webster's Third New International 

Dictionary 2635 (1986) ("adequate to permit work to be done").

For definitions of "working order" see The Random House 

Unabridged Dictionary 2189 (2d ed. 1993) ("[T]he condition of a 

mechanism when it is functioning properly."); and Webster's 

Third New International Dictionary 2635 (1986) ("[A] condition 

of a machine in which it functions according to its nature and 

purpose.").
No. 2011AP2907-CR 

18

in such operating or mechanical condition that it correctly 

performs the function or utility or the purpose of a scale." 

Id. at 405. Accordingly, the court determined that the scale's

use was permissible because it was shown to make true and 

accurate measurements. Id.

¶32 Other jurisdictions have also focused on function when 

determining whether tail lamps are in compliance with a 

statutory requirement that they be in good or proper working 

order. See Kroft v. State, 992 N.E.2d 818, 822 (Ind. Ct. App. 

2013) (determining that a tail lamp was still in good working 

order despite a dime-sized hole because there was no evidence 

the hole affected the visibility of the light to another 

vehicle); Vicknair v. State, 751 S.W.2d 180, 189-90 (Tex. Crim. 

App. 1988) (taillight in proper condition despite crack in a 

taillight because it still emitted a red light visible within 

the requisite distance).14 We likewise conclude the focus should 

be on the function of a tail lamp in determining whether it is 

in "good working order" under Wis. Stat. § 347.13(1).

¶33 The statutory definition of "tail lamp" provides that 

its intended purpose is to "designate the rear of a vehicle as a 

warning light." Wis. Stat. § 340.01(66). The language of Wis. 

Stat. § 347.13(1) clarifies that a tail lamp does so by emitting 

 

14 Contrary to Justice Roggensack's dissent's assertion, we 

do not cite to Kroft and Vicknair in support of a conclusion 

that "the officers acted unreasonably." Justice Roggensack's 

dissent, ¶112. Rather, the cases are cited for the premise that 

courts look to function to determine whether there is a 

violation of a statute.
No. 2011AP2907-CR 

19

during hours of darkness "a red light plainly visible from a 

distance of 500 feet to the rear." Accordingly, a tail lamp is 

functioning for its intended use and thus in good working order 

when during hours of darkness it emits a red warning light that 

is visible to another vehicle traveling 500 feet behind it.

¶34 We do not agree with the State that when read in the 

context of surrounding statutes Wis. Stat. § 347.13(1) requires 

all light bulbs in a tail lamp to be lit. The State points to 

Wis. Stat. § 347.06(3) and Wis. Admin. Code § Trans. 305.16(2) 

which require tail lamps to be kept in "proper working 

condition." However, "proper" is not a synonym for "perfect." 

Rather it is more akin to "good" or "suitable."15 Thus, the 

statutes requiring tail lamps to be in proper working condition 

are more in line with requiring a tail lamp to function for its 

intended purpose than with requiring all light bulbs in a tail 

lamp to function perfectly.

¶35 Construing Wis. Stat. § 347.13(1) as requiring every 

single light bulb on the back of a vehicle to be in perfect 

condition would lead to absurd and unreasonable results. Not 

only is such an interpretation inconsistent with the plain 

language of the statute, but it is also not practical 

 

15 "Proper" is defined as "[c]haracterized by 

appropriateness or suitability." The American Heritage 

Dictionary of the English Language 1452 (3d ed. 1992); see also

Random House Unabridged Dictionary 1550 (2d ed. 1993) (defining 

"proper" as "adapted or appropriate to the purpose or 

circumstances; fit; suitable"); Webster's Third New 

International Dictionary 1817 (1986) ("adequate to the 

purpose").
No. 2011AP2907-CR 

20

considering the variety of tail lamp designs today. Brown 

points to tail lamps that are composed of multiple light bulbs 

creating intricate designs. He cites as an example the tail 

lamp of an Audi, composed of thirty tiny light bulbs, which is 

pictured in his brief. We agree with Brown that there is 

nothing to suggest that a single unlit bulb out of several in a 

tail lamp would necessarily impair the tail lamp's function. 

¶36 Wisconsin Stat. § 347.13(1) requires that vehicles 

with two tail lamps not be operated during hours of darkness 

"unless both such lamps are in good working order." It would be 

unreasonable to require the public to maintain every light bulb 

in a tail lamp in perfect condition when that is more than is 

required by the statute. The legislature determined that 

visibility from 500 feet is sufficient to protect public safety 

and we defer to its policy decisions. 

¶37 Contrary to the State's assertions, the standard we 

adopt is not unworkable and does not fail to give guidance to 

police officers. This interpretation requires officers to 

determine if they can see a red light emitted from the back of a 

vehicle from a distance of 500 feet. Officers routinely have to 

gauge distances to determine whether motorists have violated 

traffic laws. See, e.g., Wis. Stat. § 346.33(1)(e) (requires 

officers to determine whether a driver making a U-turn on a 

curve or crest can be seen by another driver approaching from 

500 feet); § 346.51(1)(b) (requires officers to determine if a 

standing vehicle can be seen by operators of other vehicles from 

a distance of 500 feet); § 346.14 (requires officers to 
No. 2011AP2907-CR 

21

determine whether there are 500 feet between vehicles). We are 

confident that they can apply that ability to determine whether 

Wis. Stat. § 347.13(1) has been violated as well.

¶38 In this case, the only basis that the State presented 

for the stop of Brown's vehicle was the unlit bulb in his tail 

lamp. However, there was no evidence that his tail lamp was not 

visible from 500 feet to the rear of the car. The officers 

testified that only one of the bulbs on the back of Brown's 

vehicle was unlit. Because having one unlit bulb on the back of 

a vehicle does not on its own violate the statutory requirements 

for tail lamps, the State has failed to show that the officers 

had probable cause to believe that a traffic violation had

occurred.

¶39 We likewise reject the State's alternative argument 

that it had reasonable suspicion for the traffic stop. The 

State asserts that the officers could have reasonably believed 

that the unlit light bulb was part of the tail lamp. In this 

case, such an argument is inextricably intertwined with the 

interpretation of the underlying traffic violation. It fails 

because even assuming the officers made a mistake of fact 

regarding whether the unlit light bulb was part of the tail 

lamp, they would still have to rely on a mistake of law to have 

reasonable suspicion. 

¶40 Like probable cause, reasonable suspicion cannot be 

based on a mistake of law. Rabin v. Flynn, 725 F.3d 628, 633 

(7th Cir. 2013) ("[A] police officer's suspicion of wrongdoing 

that is premised on a mistake of law cannot justify a Terry
No. 2011AP2907-CR 

22

stop."); United States v. Tyler, 512 F.3d 405, 411 (7th Cir. 

2008) ("[A] mistake of law (as opposed to a mistake of fact) 

cannot justify an investigative detention."); Chanthasouxat, 342 

F.3d at 1279 ("[A] mistake of law cannot provide reasonable 

suspicion or probable cause to justify a traffic stop."). 

¶41 Because one unlit bulb in a tail lamp does not 

establish a violation of Wis. Stat. § 347.13(1), the unlit light 

bulb on Brown's vehicle was an insufficient basis to reasonably 

suspect that Brown had committed, was committing, or was about 

to commit a crime. Given that there was no lawful basis 

asserted as grounds for stopping Brown's vehicle, the evidence 

the officers found in the vehicle pursuant to that stop is "the 

fruit" of an illegal seizure. Harris, 206 Wis. 2d at 263. 

Accordingly, the evidence resulting from the search should be 

suppressed. 

IV

¶42 In sum, we do not interpret Wis. Stat. § 347.13(1) as 

requiring every single light bulb in a tail lamp to be lit. The 

plain language of the statute requires that a tail lamp emit a 

red light visible from 500 feet behind the vehicle during hours 

of darkness. This interpretation is further supported by 

related statutes requiring that the lamps be in proper working 

condition.

¶43 Because the only basis for the stop of Brown's vehicle 

was the unlit bulb we conclude that there was not probable cause 

or reasonable suspicion to stop the vehicle. Where the stop of 

the vehicle was unlawful, so too was its search, and the results 
No. 2011AP2907-CR 

23

of that search must be suppressed. Accordingly, we affirm the 

court of appeals.

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

affirmed.
No. 2011AP2907-CR.dtp

1

¶44 DAVID T. PROSSER, J. (dissenting). The issue 

presented in this case is whether two Milwaukee police officers 

had probable cause to stop a vehicle when they perceived what 

they believed was an unlit light bulb in the tail lamp of the 

vehicle. There is dispute whether there was or was not an unlit 

light bulb in the tail lamp of the vehicle. The majority 

concludes that it makes no difference because "we do not 

interpret Wis. Stat. § 347.13(1) as requiring every single light 

bulb in a tail lamp to be lit." Majority op., ¶3. Thus, the 

majority concludes that the officers made an unconstitutional 

mistake of law when they acted on the belief that a tail lamp 

with an unlit bulb was not in "proper working condition at all 

times" and not "in good working order." 

¶45 In my view, the conclusion that partially unlit tail 

lamps comply with Wis. Stat. § 347.13(1) if they are visible 

from 500 feet away creates a vague, unworkable standard for law 

enforcement. Consequently, I respectfully dissent.

I

¶46 On July 3, 2010, two Milwaukee police officers, 

William Feely and Michael Wawrzonek, were on patrol duty near 

2900 West Capitol Drive in the City of Milwaukee. It was 

approximately 9:30 p.m. Officer Feely was driving a marked 

squad car. Officer Wawrzonek was in the passenger seat. The 

officers spotted a 1977 Buick Electra turn south on North 28th 

Street. Both officers observed what they perceived as a 

defective tail lamp. When the squad car was approximately three 
No. 2011AP2907-CR.dtp

2

car lengths behind the Electra, it activated its red and blue 

emergency lights to make a stop of the Electra. At the same 

time, the vehicle slowed down and pulled over to the curb to 

stop.

¶47 Following the stop, the officers seized a pistol 

belonging to the defendant, Antonio D. Brown, who was riding as 

a passenger in his own vehicle because he was intoxicated. 

Brown was a convicted felon on parole. He subsequently moved to 

suppress evidence of the weapon on grounds that police "seizure" 

of his vehicle was unlawful.

¶48 At the suppression hearing on January 13, 2011, the 

two officers described the stop. Officer Wawrzonek testified:

Q. Is there anything specific about that vehicle 

that caught your attention?

A. Yeah, defective tail light.

. . . .

Q. Do you remember what tail light it was that was 

defective on that unit?

A. It was the driver side tail lamp. There is a 

wide band and there is actually three light panels on 

that wide band and one of those panels was out.

. . . .

Q. Now, when you said that there was a defective 

tail light . . . are you referring to the reflective 

red lights or the white back-up lights?

A. One of the red lights. He was going——he was 

going forward so there was no reverse going on at this 

point so I wouldn't see a white light. It was one of 

the red lights.

. . . .

Q. So two of the panels were working properly?
No. 2011AP2907-CR.dtp

3

A. That's my recollection.

¶49 When Officer Feely testified, he identified the 

specific light that appeared to be defective:

Q. And do you recall what the basis for the stop 

was, Officer?

A. Defective tail lamp.

Q. And when you say that, did you remember 

specifically which tail light was out?

A. Believe it was the driver side middle one.

Q. Would that have been a red or white light if you 

recall?

A. Red.

¶50 At a continuation of the suppression hearing on 

January 21, 2011, the driver of the Electra testified that there 

were no defects in the tail lamps. He also testified that the 

vehicle "has red lights on both sides, and a white light is the 

reverse light, and the middle light is a brake light."

¶51 The driver, Willie Lipsey (Lipsey), said that when the 

vehicle was operating with its lights on, there were only two 

red lights showing in the tail lamps on each side of the rear 

license plate. He said a red brake light situated between the 

other red lights in the tail lamp1 did not illuminate until the 

driver applied the brakes.

¶52 This description of the operation of the rear lights 

does not explain why the officers noticed a difference in the 

two tail lamp panels——with only the left panel appearing to have 

 

1 "A stop lamp may be incorporated with a tail lamp." Wis. 

Stat. § 347.14. From the testimony, it seems as though the stop 

lamp was incorporated with the tail lamp in the Electra.
No. 2011AP2907-CR.dtp

4

a gap between the lights. This description also fails to 

explain why the officers did not state that both panels were 

working perfectly when the driver applied the brakes before 

stopping at the curb. It may have been because the left brake 

light was not working when the vehicle turned the corner and 

when it came to a stop. It is also possible that one of the 

light bulbs in the tail lamp, other than the brake light, was 

out.

¶53 There appear to be only three possible scenarios: (1) 

one of the light bulbs in the left tail lamp was not working; 

(2) the officers thought that one of the light bulbs in the left 

tail lamp was not working;2 or (3) the officers were not telling 

the truth about what they saw. Although the facts remain in 

dispute, the circuit court found that the officers were credible 

when they testified that they saw a defective tail lamp and that 

Lipsey was not credible when he testified that he remembered 

that all the rear lights were functioning properly.

II

¶54 Wisconsin has an elaborate motor vehicle code,3

including detailed provisions for motor vehicle lighting 

equipment. See Wis. Stat. §§ 347.06-347.30.

¶55 Chapter 347 begins with a section that indicates that 

"Words and phrases defined in s. 340.01 are used in the same 

sense in this chapter unless a different definition is 

specifically provided." Wis. Stat. § 347.01.

 

2 This possibility would have been a mistake of fact.

3 See Wis. Stat. chs. 340-51.
No. 2011AP2907-CR.dtp

5

¶56 Section 340.01 includes definitions for numerous lamps 

such as "Clearance lamps,"4 "Direction signal lamp,"5

"Headlamp,"6 "Identification lamps,"7 "Multiple beam headlamp,"8

"Stop lamp,"9 and "Tail lamp."10 Chapter 347 contains both 

general and specific provisions governing these various types of 

lighting equipment.

¶57 For example, Wis. Stat. § 347.06 reads in part:

(1) [N]o person may operate a vehicle upon a 

highway during hours of darkness unless all headlamps, 

tail lamps and clearance lamps with which such vehicle 

is required to be equipped are lighted.

 

4 "'Clearance lamps' means lamps on the left and right sides 

of the front and rear of a vehicle which show to the front and 

rear to mark the extreme sides of the vehicle." Wis. Stat. 

§ 340.01(7).

5 "'Direction signal lamp' means a lighting device used to 

indicate the intention of the operator of a vehicle to change 

direction." Wis. Stat. § 340.01(13).

6 "'Headlamp' means a major lighting device used to provide 

general illumination ahead of a vehicle." Wis. Stat. 

§ 340.01(21).

7 "'Identification lamps' means lamps grouped in a 

horizontal row and mounted on the permanent structure of the 

vehicle at or near the vertical center line." Wis. Stat. 

§ 340.01(23m).

8 "'Multiple beam headlamp' means a headlamp designed to 

permit the operator of the vehicle to use any one of 2 or more 

distributions of light on the roadway." Wis. Stat. 

§ 340.01(36).

9 "'Stop lamp' means a device giving a steady warning light 

to the rear of a vehicle to indicate the intention of the 

operator of the vehicle to diminish speed or stop." Wis. Stat. 

§ 340.01(63).

10 "'Tail lamp' means a device to designate the rear of a 

vehicle by a warning light." Wis. Stat. § 340.01(66).
No. 2011AP2907-CR.dtp

6

. . . .

(3) The operator of a vehicle shall keep all 

lamps and reflectors with which such vehicle is 

required to be equipped reasonably clean and in proper 

working condition at all times.

¶58 Wisconsin Stat. § 347.06 is relevant to this case 

because it prohibits operation of a motor vehicle during hours 

of darkness unless "all . . . tail lamps . . . are lighted." 

Wis. Stat. § 347.06(1). Moreover, the operator of a motor 

vehicle "shall keep all lamps . . . in proper working condition 

at all times." Wis. Stat. § 347.06(3).

¶59 Wisconsin Stat. § 347.13 is entitled "Tail lamps and 

registration plate lamps." The section reads in part:

(1) No person shall operate a motor vehicle, 

mobile home or trailer or semitrailer upon a highway 

during hours of darkness unless such motor vehicle, 

mobile home or trailer or semitrailer is equipped with 

at least one tail lamp mounted on the rear which, when 

lighted during hours of darkness, emits a red light 

plainly visible from a distance of 500 feet to the 

rear. No tail lamp shall have any type of decorative 

covering that restricts the amount of light emitted 

when the tail lamp is in use. No vehicle originally 

equipped at the time of manufacture and sale with 2 

tail lamps shall be operated upon a highway during 

hours of darkness unless both such lamps are in good 

working order. This subsection does not apply to any 

type of decorative covering originally equipped on the 

vehicle at the time of manufacture and sale.

. . . .

(4) Tail lamps and registration plate lamps 

shall be so wired as to be lighted whenever the 

headlamps or auxiliary driving lamps are lighted.

Wis. Stat. § 347.13.

¶60 The first sentence of § 347.13(1) serves two purposes. 

It prohibits a person from operating a motor vehicle during 
No. 2011AP2907-CR.dtp

7

hours of darkness unless the vehicle is equipped with at least 

one tail lamp. It also establishes equipment standards for 

motor vehicle tail lamps.

¶61 Most vehicle operators seeking to comply with motor 

vehicle equipment laws are dependent upon automobile 

manufacturers and parts suppliers for the equipment on their 

vehicles. These operators expect that the tail lights they 

purchase will meet the requirements of the law. All four states 

bordering Wisconsin have statutes like Wis. Stat. § 347.13(1) 

that require 500 feet of visibility from rear lamps, implying 

that 500 feet is a common standard.

11

 

11 Every motor vehicle, trailer, or semi-trailer shall 

also exhibit at least 2 lighted lamps, commonly known 

as tail lamps, which shall be mounted on the left rear 

and right rear of the vehicle so as to throw a red 

light visible for at least 500 feet in the reverse 

direction . . . . 

625 Ill. Comp. Stat. Ann. 5/12-201(b) (West 2014). 

Every motor vehicle and every vehicle which is 

being drawn at the end of a train of vehicles shall be 

equipped with a lighted rear lamp or lamps, exhibiting 

a red light plainly visible from a distance of five 

hundred feet to the rear. All lamps and lighting 

equipment originally manufactured on a motor vehicle 

shall be kept in working condition or shall be 

replaced with equivalent equipment. 

Iowa Code Ann. § 321.387 (West 2014).

A motor vehicle, trailer, semitrailer, pole 

trailer, or vehicle which is being drawn in a train of 

vehicles shall be equipped with at least 1 rear lamp 

mounted on the rear, which, when lighted as required 

by this act, shall emit a red light plainly visible 

from a distance of 500 feet to the rear. 

Mich. Comp. Laws Ann. § 257.686(1) (West 2014).
No. 2011AP2907-CR.dtp

8

¶62 The majority opinion appears to conclude that if a 

tail lamp can be seen from 500 feet, it cannot violate the motor 

vehicle equipment statutes. Majority op., ¶3.

¶63 The next sentence in Wis. Stat. § 347.13(1), which 

bears on functionality, shows that such a conclusion is 

incorrect. The second sentence reads: "No tail lamp shall have 

any type of decorative covering that restricts the amount of 

light emitted when the tail lamp is in use." Wis. Stat. 

§ 347.13(1) (emphasis added). This sentence demonstrates that 

there is a concern that each tail light be lit and unobscured. 

The sentence does not say that a decorative covering may not 

restrict the amount of light emitted so as to reduce visibility 

unless it can be seen from 500 feet. The sentence permits no

restriction of light.

¶64 The third sentence of Wis. Stat. § 347.13(1) requires 

that there be no flaw in the tail lamps: "No vehicle originally 

equipped at the time of manufacture and sale with 2 tail lamps 

shall be operated upon a highway during hours of darkness unless 

both such lamps are in good working order." Id. (emphasis 

added). This sentence requires both tail lamps to be operating 

in good working order. When this sentence is combined with Wis. 

Stat. § 347.06(3), an operator is required to keep all tail 

 

"Every motor vehicle and every vehicle that is being drawn 

at the end of a train of vehicles must be equipped with at least 

one taillamp, exhibiting a red light plainly visible from a 

distance of 500 feet to the rear." Minn. Stat. Ann. 

§ 169.50.1(a) (West 2014).
No. 2011AP2907-CR.dtp

9

lamps in proper working condition at all times; that is, in good 

working order at all times.

¶65 Wisconsin Stat. § 347.14, relating to "stop lamps," 

reads in part as follows:

(1) No person shall operate a motor 

vehicle . . . upon a highway unless such motor 

vehicle . . . is equipped with at least one stop lamp 

mounted on the rear and meeting the specifications set 

forth in this section. . . . A stop lamp may be 

incorporated with a tail lamp. No vehicle originally 

equipped at the time of manufacture and sale with 2 

stop lamps shall be operated upon a highway unless 

both such lamps are in good working order.

(2) A stop lamp shall be so constructed as to be 

actuated upon application of the service or foot 

brake . . . and shall emit a red or amber light 

plainly visible and understandable from all distances 

up to 300 feet to the rear during normal sunlight when 

viewed from the driver's seat of the vehicle 

following.

Wis. Stat. § 347.14 (emphasis added).

¶66 Like the previous section, Wis. Stat. § 347.14 

requires a particular type of lighting equipment to be "in good 

working order." Inasmuch as a 1977 Buick Electra has only one 

rear brake light on each side of the vehicle, a brake light that 

is defective is 100 percent defective and cannot be——under any 

reasonable definition——in "proper working condition" or "in good 

working order."

¶67 The Wisconsin Department of Transportation (DOT) has 

developed administrative rules to flesh out its lighting 

equipment statutes. See Wis. Admin. Code § TRANS 305.

¶68 Among these rules are the following:

Trans 305.01 Purpose and Scope.
No. 2011AP2907-CR.dtp

10

(1) The purpose of this chapter is to prescribe 

minimum equipment requirements for vehicles and 

standards for the equipment used on vehicles. 

. . . .

Trans 305.02 Applicability.

. . . .

(7) Nothing in this chapter is intended to 

modify the provisions of ch. 347, Stats., and all 

vehicles to which this chapter applies shall also 

comply with the requirements of ch. 347, Stats.

. . . .

Trans 305.03 Enforcement.

No person may operate or allow to be operated on 

Wisconsin highways any vehicle subject to this chapter 

that is not in conformity with the applicable 

requirements of this chapter.

. . . .

Trans 305.15 Stop Lamps.

(1) Every automobile originally manufactured 

commencing with the 1950 models . . . shall be 

equipped with at least 2 stop lamps. All other motor 

vehicles shall be equipped with at least one stop 

lamp.

(2) The stop lamps of every vehicle shall be 

maintained in proper working condition and in 

conformity with this section and s. 347.14, Stats.

. . . .

Trans 305.16 Tail Lamps.

(1) Every automobile originally manufactured 

commencing with the 1950 models . . . shall be 

equipped with at least 2 tail lamps. All other motor 

vehicles shall be equipped with at least one tail

lamp.

(2) The tail lamps of every motor vehicle shall 

be maintained in proper working condition and in 
No. 2011AP2907-CR.dtp

11

conformity with this section and s. 347.13 (1) and 

(2), Stats.

(3) All wiring and connections shall be 

maintained in good condition.

. . . .

(5) The tail lamps shall be so wired as to be 

lighted whenever the parking lamp or headlamps are 

lighted.

Wis. Admin. Code §§ TRANS 305.01 (emphasis added), 305.02, 

305.03, 305.15 (emphasis added), 305.16 (emphasis added).

¶69 The rules repeat the phrase "in proper working 

condition" from Wis. Stat. § 347.06(3), even in Wis. Admin. 

Code. § TRANS 305.15 and § TRANS 305.16, which implement Wis. 

Stat. §§ 347.14 and 347.13 respectively. Those statutes use the 

phrase "in good working order." This suggests that the DOT sees 

these phrases as interchangeable.

¶70 As the majority notes, we may turn to a dictionary to 

construe undefined words according to their ordinary meanings. 

Majority op., ¶28. However, the majority's definition of "good 

working order" is incomplete because it defines "good working 

order" and "working order" to mean essentially the same thing. 

Using dictionary definitions, the majority defines "good working 

order" as "suitable or functioning for the intended use." Id., 

¶29 (footnote omitted).

¶71 According to Webster's Third New International 

Dictionary 2635 (1986), "Working order" means "a condition of a 

machine in which it functions according to its nature and 

purpose . . . ." This definition is substantially similar to 

the majority's definition of "good working order." Thus, the 
No. 2011AP2907-CR.dtp

12

majority's definition renders "good" mere surplusage. In my 

view, "good working order" must mean something more than

"working order."12 

¶72 As the majority notes, one definition of "good" is 

"adapted to the end designed or proposed: satisfactory in 

performance." Majority op., ¶29 n.13. However, there is more 

to the definition. The cited definition goes on to define 

"good" as "free from flaws or defects" or "not impaired." 

Webster's Third New International Dictionary 978 (1986). The 

definition of "good" that includes "free from flaws or defects" 

is more helpful than the majority's definition because it better 

fits within the framework of statutory analysis and the aversion 

to surplusage. It also gives law enforcement a clear standard 

to apply when confronted with broken tail lights.

¶73 Because "proper working condition" and "good working 

order" appear to be interchangeable terms, it is hard to imagine 

that a tail lamp or a stop lamp that has defective lights can be 

described as being "in proper working condition" and the 

condition to which the lamp should be kept "at all times." Wis. 

Stat. § 347.06(3).

 

12 Two online definitions of "working order" are different 

from the majority's minimalist definition. One dictionary 

suggests "in working order" means "working correctly, without 

any problems." MacMillan Dictionary, 

http://www.macmillandictionary.com/us/dictionary/american/workin

g-order (last visited July 3, 2014). Another dictionary 

suggests that "(in) working order" means "working properly and 

not broken" or "be in good/perfect/full etc working order." 

Longman Dictionary of Contemporary English, 

http://www.ldoceonline.com/dictionary/working_1 (last visited 

July 3, 2014).
No. 2011AP2907-CR.dtp

13

III

¶74 This case is about much more than the felony 

conviction of Antonio Brown. The majority opinion significantly 

dilutes the meaning of "proper working condition" and "good 

working order" in the lighting equipment statutes. This is 

likely to affect the enforcement of these statutes.

¶75 Wisconsin Stat. § 347.30 provides:

(1) Any person violating s. 347.06 or 347.13 

(2), (3) or (4) may be required to forfeit not less 

than $10 nor more than $20 for the first offense and 

not less than $25 nor more than $50 for the 2nd or 

subsequent conviction within a year. 

(2) Any person violating ss. 347.03, 347.07 to 

347.12, 347.13(1) or 347.14 to 347.29 may be required 

to forfeit not less than $10 nor more than $200.

¶76 The majority concludes that Wis. Stat. § 347.13(1) 

does not require "every single light bulb in a tail lamp to be 

lit." Majority op., ¶3. But it does not say what is required 

for a violation of this statute. The answer cannot turn on 

whether the tail lamp can be seen from 500 feet because that is 

not the correct statutory standard and would pose an impossible 

burden of proof on law enforcement.

¶77 The majority's analysis is bound to affect the 

interpretation of other lighting equipment statutes involving 

more than one light, and other statutes that employ the phrases 

"in proper working condition" or "in good working order."13

 

13 For instance, there are at least 11 statutes in addition 

to Wis. Stat. § 347.13 that use the phrase "good working order." 

See Wis. Stat. §§ 30.62, 48.658, 283.31, 285.30, 347.14, 347.36, 

347.38, 347.42, 348.15, 350.055(1m) (2013-14), 350.095.
No. 2011AP2907-CR.dtp

14

¶78 Because the court has diluted the meaning of these 

phrases, it has seriously impaired law enforcement's ability to 

stop vehicles to alert the drivers of equipment defects. Of 

course these stops sometimes serve other purposes. Now, these 

purposes are in jeopardy because of the confusion created by the 

court's decision.

¶79 Now that law enforcement officers are precluded from 

pulling over vehicles with flawed tail lamps if the tail lamps 

are visible from 500 feet, there is likely to be a bonanza for 

litigants seeking to challenge motor vehicle stops. The 

uncertainty in the law will create difficulties for law 

enforcement and new burdens on circuit courts.

¶80 In my view, this court is making a mistake. It should 

be providing a clear, commonsense, easy-to-understand standard: 

if a tail light or brake light is out, the tail lamp or stop 

lamp is not in good working order.

¶81 For the foregoing reasons, I respectfully dissent.
No. 2011AP2907-CR.pdr

1

¶82 PATIENCE DRAKE ROGGENSACK, J. (dissenting). For 

purposes of this dissent, I assume, arguendo, that the majority 

opinion's conclusion that Antonio Brown's tail lamp was in "good 

working order" under Wis. Stat. § 347.13(1) is correct. I write 

in dissent to explain why the majority opinion's conclusion that 

"an officer's mistake of law is not sufficient grounds for a 

stop" is not correct.1 See State v. Longcore, 226 Wis. 2d 1, 9, 

593 N.W.2d 412 (Ct. App. 1999). I conclude that the legality of 

a stop depends on whether under the totality of the 

circumstances a reasonable officer could have believed that a 

law violation was occurring. See United States v. Martin, 411 

F.3d 998, 1001 (8th Cir. 2005) (a search is valid when "an 

objectively reasonable police officer could have formed a 

reasonable suspicion that [a defendant] was committing a . . . 

violation"). Therefore, "in mistake cases[,] the question is 

simply whether the mistake, whether of law or of fact, was an 

objectively reasonable one." United States v. Smart, 393 F.3d 

767, 770 (8th Cir. 2005). I further conclude that under the 

totality of the circumstances a reasonable officer could have 

believed that Brown's tail lamp violated § 347.13(1). 

Accordingly, I would reverse the decision of the court of 

appeals, and I respectfully dissent from the majority opinion. 

I. BACKGROUND

¶83 On the evening of July 3, 2010, Milwaukee police 

officers Michael Wawrzonek and William Feely were patrolling an 

 

1 Majority op., ¶25. 
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area near Capitol Drive as part of an effort to "saturate areas 

that are targeted" by armed robbers. Both officers testified 

that they observed a 1977 Buick Electra with one panel of the 

driver's side tail lamp, which had three panels, not 

illuminated. They pulled the vehicle over based on what they 

described as a "defective tail light." 

¶84 After stopping the car, Officer Feely approached the 

vehicle and noticed Brown, who was sitting in the back seat, 

kick a small wooden object under the passenger seat. He ordered 

all of the occupants out of the car, and ultimately recovered a 

.38 Taurus revolver from under the front seat. 

¶85 The State charged Brown with felony possession of a

firearm. Brown moved to suppress all evidence obtained from the 

stop because officers lacked probable cause to stop the car. 

¶86 The circuit court denied the motion, finding that the 

officers' observation of the unlit panel justified the stop. In 

denying Brown's motion for post-conviction relief, the circuit 

court reiterated that stopping the car was proper because the 

officers "believed that the taillight was out." Even if it is 

"later to be shown that somehow that . . . light is supposed to 

not be on at that time," the circuit court reasoned that would 

not be "a fatal flaw in the stop itself." 

¶87 The court of appeals reversed. It concluded that "[a] 

tail lamp with one of three light bulbs unlit does not violate 

Wis. Stat. § 347.13(1) when it otherwise meets the statutory 

definition of a tail lamp." State v. Brown, 2013 WI App 17, 

¶21, 346 Wis. 2d 98, 827 N.W.2d 903. Because "[t]he officers 
No. 2011AP2907-CR.pdr

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mistakenly believed that the law required all of the tail lamps 

light bulbs to be lit; and 'a lawful stop cannot be predicated 

upon a mistake of law,'" it held that the evidence should have 

been suppressed. Id. (quoting Longcore, 226 Wis. 2d at 9). 

¶88 We granted the State's petition for review, which asks 

us to decide whether the officers had probable cause or 

reasonable suspicion to stop Brown's car and whether the 

officers had reasonable suspicion to search Brown's car. We 

asked for additional briefing on the following issues: 

(1) whether the officer had reasonable suspicion 

to stop Brown's vehicle because the officer believed 

that Wis. Stat. § 347.13(1) was violated when not all 

the tail light bulbs on Brown's vehicle were working; 

[and] 

(2) whether, assuming an officer makes a good 

faith mistake of law on which the officer makes a 

traffic stop . . . that mistake of law nevertheless 

require[s] reviewing courts to conclude that the stop 

was not lawful.

II. DISCUSSION

A. Standard of Review

¶89 This case is about the legality of a traffic stop, 

which is constitutional if supported by probable cause or 

reasonable suspicion. State v. Anagnos, 2012 WI 64, ¶20, 341 

Wis. 2d 576, 815 N.W.2d 675. We evaluate a stop according to 

two steps. "First, we review the circuit court's findings of 

historical fact under the clearly erroneous standard." Id. at 

¶21. Next, "we review independently the application of those 

facts to constitutional principles." State v. Post, 2007 WI 60, 

¶8, 301 Wis. 2d 1, 733 N.W.2d 634. 
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B. Lawfulness of Stop

1. Introduction

¶90 The majority opinion concludes that "an officer's 

mistake of law is not sufficient grounds for a stop."2 See also

Longcore, 226 Wis. 2d at 9. The majority opinion string-cites 

cases from other jurisdictions that have concluded that an 

officer's mistake of law cannot sustain a stop.3 The majority 

opinion reasons that admitting evidence obtained based on a 

mistake of law "would defeat the purpose of the exclusionary 

rule, for it would remove the incentive for police to make 

certain that they properly understand the law that they are 

entrusted to enforce and obey."

4 Because officers' understanding 

of Wis. Stat. § 347.13(1),5 which is contrary to the majority 

opinion's interpretation herein, provided the sole basis for the 

 

2 Id., ¶25. 

3 Id.

4 Id., ¶24 (quoting United States v. McDonald, 453 F.3d 958, 

962 (7th Cir. 2006)) (further citation omitted).

5 Wisconsin Stat. § 347.13(1) provides in relevant part as 

follows:

No person shall operate a motor vehicle . . . 

during hours of darkness unless such motor vehicle 

. . . is equipped with at least one tail lamp mounted 

on the rear which, when lighted during hours of 

darkness, emits a red light plainly visible from a 

distance of 500 feet to the rear. No tail lamp shall 

have any type of decorative covering that restricts 

the amount of light emitted when the tail lamp is in 

use. No vehicle originally equipped at the time of 

manufacture and sale with 2 tail lamps shall be 

operated upon a highway during hours of darkness 

unless both such lamps are in good working order. 
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stop in this case, it suppresses all evidence obtained from the 

stop.

¶91 I do not agree that an officer's mistake of law 

renders a search per se unreasonable. A statute may be 

ambiguous or unclear so that an objectively reasonable officer 

could form a reasonable belief that a violation was occurring, 

even when it was not. In that instance, I would uphold the 

search. While the majority opinion's circuit-counting shows

that this may be a minority position, I nonetheless conclude 

that it is the conclusion the law requires for the reasons I now 

explain.

2. General Fourth Amendment principles

¶92 The Fourth Amendment to the United States Constitution 

protects against unreasonable searches and seizures. "Temporary 

detention of individuals during the stop of an automobile by the 

police, even if only for a brief period and for a limited 

purpose, constitutes a 'seizure' of 'persons' within the meaning 

of [that] provision." Whren v. United States, 517 U.S. 806, 

809-10 (1996); see State v. Popke, 2009 WI 37, ¶11, 317 Wis. 2d 

118, 765 N.W.2d 569. A traffic stop is reasonable, and 

therefore constitutional, if: (1) an officer has probable cause 

to believe a law violation has occurred; or (2) an officer has 

reasonable suspicion that a crime is about to be or has been 

committed. Whren, 517 U.S. at 810; Terry v. Ohio, 392 U.S. 1, 

22 (1968). "Taken together, then, Terry and Whren stand for the 

proposition that a traffic stop will be deemed a reasonable 

'seizure' when an objective review of the facts shows that an 
No. 2011AP2907-CR.pdr

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officer possessed specific, articulable facts that an individual 

was violating a traffic law at the time of the stop." United 

States v. Delfin-Colina, 464 F.3d 392, 398 (3d Cir. 2006). 

¶93 Evidence obtained in violation of the Fourth Amendment 

may be suppressed under the exclusionary rule. Weeks v. United 

States, 232 U.S. 383, 398 (1914); Hoyer v. State, 180 Wis. 407, 

417, 193 N.W. 89 (1923). The exclusionary rule is "a judicially 

created remedy designed to safeguard Fourth Amendment rights 

generally through its deterrent effect, rather than a personal 

constitutional right of the party aggrieved." United States v. 

Leon, 468 U.S. 897, 906 (1984) (quoting United States v. 

Calandra, 414 U.S. 338, 348 (1974)).

6 By preventing the use of 

illegally obtained evidence, it not only deters unconstitutional

police conduct, but also protects the integrity of the judicial 

process by refusing to sanction unlawful searches. State v. 

Knapp, 2005 WI 127, ¶79, 285 Wis. 2d 86, 700 N.W.2d 899.

7 

¶94 In some instances, "the substantial social costs of 

excluding relevant evidence" obtained illegally outweigh "the 

benefit of deterring future police misconduct" produced by the 

rule. State v. Eason, 2001 WI 98, ¶31, 245 Wis. 2d 206, 629 

N.W.2d 625; accord Leon, 468 U.S. at 907-09. We therefore have 

recognized a good-faith exception to the exclusionary rule in 

 

6 See also Conrad v. State, 63 Wis. 2d 616, 636, 218 N.W.2d 

252 (1974) ("The exclusionary rule is a judge-made one in 

furtherance of conduct that courts have considered to be in the 

public interest and to suppress conduct that is not.").

7 But see id. at 635 (questioning the effectiveness of the 

exclusionary rule to accomplish its objectives.)
No. 2011AP2907-CR.pdr

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some circumstances. Eason, 245 Wis. 2d 206, ¶28. We recently 

explained our approach to the exclusionary rule and its 

exceptions as follows:

To trigger the exclusionary rule, police conduct must 

be sufficiently deliberate that exclusion can 

meaningfully deter it, and sufficiently culpable that 

such deterrence is worth the price paid by the justice 

system. . . . [T]he exclusionary rule serves to deter 

deliberate, reckless, or grossly negligent conduct, or 

in some circumstances recurring or systemic 

negligence.

State v. Dearborn, 2010 WI 84, ¶36, 327 Wis. 2d 252, 786 N.W.2d 

97 (quoting Herring v. United States, 555 U.S. 135, 144 (2009)).

¶95 For example, when an officer reasonably relies on a 

warrant issued by an independent magistrate, but the warrant is 

later held to be invalid, evidence seized in reliance on that 

warrant may nonetheless be admissible. Eason, 245 Wis. 2d 206, 

¶3; Leon, 468 U.S. at 922. In Eason, we explained that in such 

a situation, the exclusionary rule would not serve its purpose 

of deterring police misconduct because no misconduct occurred. 

Eason, 245 Wis. 2d 206, ¶55. Although it might later be 

discovered that an officer had no legal basis for a search 

because the warrant on which the officer relied was defective, 

the officer nonetheless could have acted reasonably. Id. at ¶3. 

Because there is "no real benefit in regard to deterrence, the 

social cost of excluding relevant evidence . . . [is] the 

determining factor." Id. at ¶58.

¶96 Suppression is likewise not required when an officer 

relies in good faith on a substantive criminal statute that is 

later held unconstitutional, Michigan v. DeFillippo, 443 U.S. 
No. 2011AP2907-CR.pdr

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31, 39-40 (1979), or "when the officer reasonably relies on 

clear and settled precedent," Dearborn, 327 Wis. 2d 252, ¶46. 

See also Davis v. United States, __ U.S. __, 131 S. Ct. 2419, 

2423-24 (2011). There again, because the officer is acting 

reasonably, "the exclusionary rule would have absolutely no 

deterrent effect on officer misconduct, while at the same time 

coming with the cost of allowing evidence of wrongdoing to be 

excluded." Dearborn, 327 Wis. 2d 252, ¶44. 

¶97 And finally, when the basis for a traffic stop is 

reasonable suspicion that criminal activity is afoot, the fruits 

of the stop may be used against a defendant when the officer's 

belief is reasonable, even if he is wrong and the defendant did 

not actually commit an offense. United States v. Thomas, 93 

F.3d 479, 485 (8th Cir. 1996). "The touchstone of the Fourth 

Amendment is reasonableness" because only unreasonable seizures 

are prohibited. United States v. Knights, 534 U.S. 112, 118-19 

(2001). Therefore, an officer's conduct is examined to 

determine whether it was reasonable.

3. Mistakes of fact and law

¶98 Other jurisdictions allow the use of evidence obtained 

from a stop based on a mistake of fact.8 In other words, "an 

 

8 E.g., United States v. Delfin-Colina, 464 F.3d 392, 398 

(3d Cir. 2006) ("mistakes of fact are rarely fatal to an 

officer's reasonable, articulable belief that an individual was 

violating a traffic ordinance at the time of a stop"); United 

States v. Chanthasouxat, 342 F.3d 1271, 1276 (11th Cir. 2003) 

("A traffic stopped based on an officer's incorrect but 

reasonable assessment of facts does not violate the Fourth 

Amendment."); United States v. Cashman, 216 F.3d 582, 587 (7th 

Cir. 2000) ("the Fourth Amendment requires only a reasonable 

assessment of the facts, not a perfectly accurate one").
No. 2011AP2907-CR.pdr

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officer need not be factually accurate in her belief that a 

traffic law had been violated but, instead, need only produce 

facts establishing that she reasonably believed that a violation 

had taken place." Delfin-Colina, 464 F.3d at 398. This is so

"because of the intensely fact-sensitive nature of reasonable 

suspicion and probable cause determinations." United States v. 

Chanthasouxat, 342 F.3d 1271, 1276 (11th Cir. 2003). When an 

officer is mistaken as to whether observed conduct is a 

violation, the law is less settled.

¶99 The majority opinion string-cites cases that have not 

allowed an officer's mistake of law to serve as the basis for a 

stop.9 The majority opinion asserts that "[a]n officer cannot 

have a reasonable belief that a violation of the law occurred 

when the acts to which an officer points as supporting probable 

cause are not prohibited by law." United States v. McDonald, 

453 F.3d 958, 961 (7th Cir. 2006). Under that view, "[i]t makes 

no difference that an officer holds an understandable or 'good 

faith' belief that a law has been broken." Id. at 961-62. 

Other jurisdictions adopt a somewhat softer approach under which 

"'[s]tops premised on a mistake of law . . . are generally held 

to be unconstitutional' . . . [but] [a] stop is lawful despite a 

mistake of law . . . if an objectively valid basis for the stop 

nonetheless exists." United States v. Booker, 496 F.3d 717, 722 

(D.C. Cir. 2007) (quoting United States v. Coplin, 463 F.3d 96, 

 

9 Majority op., ¶25.
No. 2011AP2907-CR.pdr

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101 (1st Cir. 2006));10 see Delfin-Colina, 464 F.3d at 399 ("In 

situations where an objective review of the record evidence 

establishes reasonable grounds to conclude that the stopped 

individual has in fact violated the traffic-code provision cited 

by the officer, the stop is constitutional even if the officer 

is mistaken about the scope of activities actually proscribed by 

the cited traffic-code provision."). The majority does not

discuss the reasoning of contrary authority that I conclude is 

persuasive.

¶100 In some jurisdictions, "the validity of a stop depends 

on whether the officer's actions were objectively reasonable in 

the circumstances, and in mistake cases the question is simply 

whether the mistake, whether of law or of fact, was an 

 

10 The United States Supreme Court vacated the judgment in 

Booker and remanded to the district court for further 

consideration in light of Arizona v. Gant, 556 U.S. 332 (2009). 

Booker v. United States, 556 U.S. 1218 (2009). The D.C. 

Circuit's holding regarding stops based on mistakes of law, 

however, remains good law. See United States v. Williams, 878 

F. Supp. 2d 190, 200 n.4 (D.D.C. 2012). Prior decisions of the 

D.C. Circuit on the same point also remain in tact. United 

States v. Southerland, 486 F.3d 1355, 1359 (D.C. Cir. 2007) 

(stop was lawful "even assuming [officers] were mistaken that 

the law required display of the front plate on the bumper"); 

United States v. Bookhardt, 277 F.3d 558, 565 n.9 (D.C. Cir. 

2002) (where an independent valid ground for an arrest exists, 

there is no reason to distinguish between arrests "where the 

crime charged was not actually a crime" and arrests "in which 

the charged offense was a crime but the officer lacked probable 

cause to believe it had been committed").
No. 2011AP2907-CR.pdr

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objectively reasonable one." Smart, 393 F.3d at 770.11 That is, 

there is "no constitutional requirement to distinguish between 

mistakes of fact and mistakes of law" and an officer's mistake 

of law is not per se unreasonable. State v. Heien, 737 S.E.2d 

351, 358 (N.C. 2012); see also United States v. Southerland, 486 

F.3d 1355, 1359 (D.C. Cir. 2007) (concluding a stop was lawful, 

even assuming the officers were mistaken about what the law 

required, because their interpretation of the law was 

objectively reasonable under the circumstances).

¶101 One reason for concluding that a stop can be 

reasonable notwithstanding a mistake of law is that 

determinations about the validity of traffic stops are not "to 

be made with the vision of hindsight, but instead by looking to 

what the officer reasonably knew at the time." United States v. 

Sanders, 196 F.3d 910, 913 (8th Cir. 1999). Because courts 

"should not expect state highway patrolmen to interpret the 

traffic laws with the subtlety and expertise of a criminal 

defense attorney," it is possible that an officer could form a 

reasonable, yet mistaken, understanding of the law. Id. In 

 

11 See also Harrison v. State, 800 So. 2d 1134, 1139 (Miss. 

2001) ("deputies had probable cause to stop Harrison, even 

though it was based on a mistake of law"); DeChene v. Smallwood, 

311 S.E.2d 749, 751 (Va. 1984) ("an arrest resulting from a 

mistake of law should be judged by the same test as one stemming 

from a mistake of fact"); McConnell v. State, 374 S.E.2d 111, 

113 (Ga. Ct. App. 1988) ("If the officer acting in good faith 

believes that an unlawful act has been committed, his actions 

are not rendered improper by a later legal determination that

the defendant's actions were not a crime according to a 

technical legal definition or distinction determined to exist in 

the penal statute.").
No. 2011AP2907-CR.pdr

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those situations, "[a] post hoc judicial interpretation of a 

substantive traffic law does not determine the reasonableness of 

a previous traffic stop within the meaning of the state and 

federal constitutions." Heien, 737 S.E.2d at 357.

¶102 I conclude that a traffic stop is valid when an 

officer reasonably believes that a law has been or is about to 

broken, notwithstanding "a later legal determination that the 

defendant's actions were not a crime according to a technical 

legal definition or distinction." McConnell v. State, 374 

S.E.2d 111, 113 (Ga. Ct. App. 1988). As the Eighth Circuit 

explained, "neither mistake of law nor mistake of fact renders a 

traffic stop illegal so long as the officer's actions were 

objectively reasonable in the circumstances." United States v. 

Bueno, 443 F.3d 1017, 1024 (8th Cir. 2006). Accordingly, when a 

statute is either ambiguous or unclear so that an objectively 

reasonable officer could have believed that a violation was 

occurring, and that belief turns out to be incorrect, I would 

uphold the search. 

¶103 This approach is consistent with the cornerstone of 

our Fourth Amendment jurisprudence: law enforcement must act 

reasonably. Reasonable suspicion does not involve a technical

analysis. As with probable cause, it invokes "the factual and 

practical considerations of everyday life on which reasonable 

and prudent [persons], not legal technicians, act." See

Brinegar v. United States, 338 U.S. 160, 175 (1949). While it 

is true that, as a matter of policy, courts should not destroy 

incentives for officers to "properly understand the law," I 
No. 2011AP2907-CR.pdr

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nevertheless conclude that an officer can make an objectively 

reasonable mistake of law. This is particularly true where, as 

here, members of this court reasonably interpreted Wis. Stat. 

§ 347.13(1) and came to contradicting constructions12 and the law 

at issue is a traffic code provision that has not been 

previously interpreted in a published decision.

13 

¶104 There are several arguments against this approach that 

merit discussion. First, some courts say that "[t]o create an 

exception here would defeat the purpose of the 

exclusionary rule, for it would remove the incentive for police 

to make certain that they properly understand the law that they 

are entrusted to enforce and obey." McDonald, 453 F.3d at 962 

(quoting United States v. Lopez-Soto, 205 F.3d 1101, 1106 (9th 

Cir. 2000)). Additionally, "if officers are allowed to stop 

vehicles based upon their subjective belief that traffic laws 

have been violated even where no such violation has, in fact, 

occurred, the potential for abuse of traffic infractions as 

pretext for effecting stops [could] seem[] boundless and the 

costs to privacy rights excessive." United States v. LopezValdez, 178 F.3d 282, 289 (5th Cir. 1999). And finally, the 

rule excluding evidence from stops based on mistakes of law 

aligns with the principle that courts should not use a statute's 

 

12 See Prosser, J., dissenting, ¶73. 

13 In an unpublished decision, the court of appeals held 

that "[a] tail lamp with a burnt out bulb cannot be said to be 

'in good working order.'" State v. Olson, No. 2010AP149-CR, 

unpublished slip op., ¶12 (Wis. Ct. App. Aug. 5, 2010). 
No. 2011AP2907-CR.pdr

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ambiguity or vagueness against a defendant. Chanthasouxat, 342 

F.3d at 1278-79. 

¶105 Criticism about the incentives this "boundless" rule 

would create are grounded in a misunderstanding of the proper 

inquiry. The question is not whether a particular officer made 

a mistake of law. Rather, it is whether, under a totality of 

the circumstances an objectively reasonable officer could have 

understood the law in such a way. The stopping point is 

reasonableness. Because a mistake of law must be reasonable, 

this approach does not invite abuse. 

¶106 As to the fact that sustaining a search premised on a 

mistake of law has the effect of using an ambiguity against a 

defendant, I agree with the following assessment of the North 

Carolina Supreme Court: 

[T]he reasonable suspicion standard does not require 

an officer actually to witness a violation of the law 

before making a stop. That rule generally applies 

regardless of the particular substantive law at issue, 

and results in part because Terry stops are conducted 

not only to investigate past crime but also to halt 

potentially ongoing crime, to thwart contemplated 

future crime, and, most importantly in these 

circumstances, to protect the public from potentially 

dangerous activity. 

Heien, 737 S.E.2d at 356-57 (citations omitted). I likewise 

conclude that "because we [should be] concerned for maintaining 

safe roadways, we [should] not want to discourage our police 

officers from conducting stops for perceived traffic 

violations." Id. at 357. 

¶107 I therefore conclude that when an officer's mistake of 

law is reasonable, the costs of excluding evidence are not 
No. 2011AP2907-CR.pdr

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outweighed by the benefit of deterrence. See Eason, 245 Wis. 2d 

206, ¶31. A reasonable mistake of law is, by definition, not 

the kind of police misconduct the exclusionary rule aims to 

deter. It is not the result of deliberate misconduct, 

recklessness, or grossly negligent performance of duty. See

Dearborn, 327 Wis. 2d 252, ¶36. It is an objectively reasonable 

interpretation that a later legal determination declares 

incorrect. In those situations, I see no reason to distinguish 

between mistakes of law and fact, and would uphold a traffic 

stop if under the totality of the circumstances the officer's 

interpretation of the law is objectively reasonable.

4. Application

¶108 I conclude that the officers acted reasonably 

notwithstanding the majority opinion's determination that Wis. 

Stat. § 347.13(1) does not require every panel in a tail lamp to 

be lit. Section 347.13(1) requires a tail lamp to be in "good 

working order." Although I assume, arguendo, that a tail lamp 

is in good working order when it is visible from 500 feet, a 

reasonable officer could have believed otherwise. In other 

words, at the time of the stop, "good working order" was 

ambiguous and the officers acted reasonably. See Teschendorf v. 

State Farm Ins. Cos., 2006 WI 89, ¶20, 293 Wis. 2d 123, 717 

N.W.2d 258 ("[a] statute that is unambiguous in one context may 

be ambiguous in another").

¶109 To explain further, a tail lamp is "a device to 

designate the rear of a vehicle by a warning light." Wis. Stat. 

§ 340.01(66). The individual panels of a tail lamp generally 
No. 2011AP2907-CR.pdr

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function together as a unitary device. The majority opinion 

concludes that the device is functional when the light it emits 

can be viewed from a distance of 500 feet.14 It takes no great 

leap of logic to conclude that an unlit panel might impair the 

function of the lamp. As Justice Prosser explains, "it is hard 

to imagine that a tail lamp or a stop lamp that has defective 

lights can be described as being 'in proper working 

condition.'"15 Put differently, a reasonable officer could have 

suspected that the unlit panel in Brown's tail lamp violated 

Wis. Stat. § 347.13(1) because an unlit panel could render the 

tail lamp less visible, or even invisible, from a distance of 

500 feet.16

¶110 I also note that the court of appeals has previously 

interpreted Wis. Stat. § 347.13(1) differently than the majority 

opinion does today. In State v. Olson, No. 2010AP149-CR, 

unpublished slip op. (Wis. Ct. App. Aug. 5, 2010), an officer 

observed "a slow moving vehicle equipped with four tail lamp 

bulbs, one of which was burnt out" and stopped the vehicle. Id.

at ¶2. The court of appeals upheld the stop, concluding that 

"[a] tail lamp with a burnt out bulb cannot be said to be 'in 

good working order.'" Id. at ¶12. "Though not dispositive, the 

fact that [courts] reached contradictory interpretations, 

 

14 Majority op., ¶33. 

15 Prosser, J., dissenting, ¶73.

16 Moreover, the record does not indicate whether the tail 

lamp was visible from a distance of 500 feet. It is possible 

then, given the record before us, that the tail lamp violated 

Wis. Stat. § 347.13(1).
No. 2011AP2907-CR.pdr

17

despite both courts concluding that the statute was clear, is 

indicative of ambiguity." Teschendorf, 293 Wis. 2d 123, ¶19.

¶111 The Mississippi Supreme Court upheld a stop based on a 

similar mistake of law to the one in the present case. In Moore 

v. State, 986 So. 2d 928 (Miss. 2008), an officer stopped a 

vehicle for having only one working tail lamp. Id. at 929. 

There, the court upheld the search even though it was "clear [to 

the court of appeals] that what the police observed did not 

constitute a violation of the cited traffic law." Id. at 931 

(citation omitted). The officers' mistake in the present case 

is equally reasonable.

¶112 The majority cites to two cases in support of its 

conclusion that the officers acted unreasonably because the tail 

lamp was functional and therefore in good working order: Kroft 

v. State, 992 N.E.2d 818 (Ind. Ct. App. 2013) and Vicknair v. 

State, 751 S.W.2d 180 (Tex. Crim. App. 1986).17 In Kroft, an 

officer stopped a vehicle with a dime-sized hole in the plastic 

cover of a tail lamp. Kroft, 992 N.E.2d at 820. Rejecting the 

State's argument that the tail lamp was not in good working 

order, the court concluded that "there [wa]s simply no evidence 

[the vehicle] posed any danger to motorists approaching [the 

vehicle] from behind" and the officer "did not testify that he 

had trouble spotting [the vehicle] from behind." Id. at 822. 

Vicknair involved a similar defect, a cracked tail lamp. 

Vicknair, 751 S.W.2d at 187. There, the court concluded that 

 

17 Majority op., ¶32.
No. 2011AP2907-CR.pdr

18

the device was in good working order because it was still 

visible from the requisite distance. Id. at 189-90. 

¶113 These cases are easily distinguished. Unlike in Kroft

and Vicknair, the defect in the present case implicates the 

function of a tail lamp, which the defects in Kroft and Vicknair

did not. Here, the totality of the circumstances on July 3, 

2010, could have led a reasonable officer to suspect that 

Brown's vehicle violated the law because a panel in the tail 

lamp was not functioning. 

III. CONCLUSION

¶114 For purposes of this dissent, I assume, arguendo, that 

the majority opinion's conclusion that Brown's tail lamp was in 

"good working order" under Wis. Stat. § 347.13(1) is correct. I 

write in dissent to explain why the majority opinion's 

conclusion that "an officer's mistake of law is not sufficient 

grounds for a stop" is not correct.18 See Longcore, 226 Wis. 2d 

at 9. I conclude that the legality of a stop depends on whether

under the totality of the circumstances a reasonable officer 

could have believed that a law violation was occurring. See

Martin, 411 F.3d at 1001 (a search is valid when "an objectively 

reasonable police officer could have formed a reasonable 

suspicion that [a defendant] was committing a . . . violation"). 

Therefore, "in mistake cases[,] the question is simply whether 

the mistake, whether of law or of fact, was an objectively 

reasonable one." Smart, 393 F.3d at 770. I further conclude 

that under the totality of the circumstances a reasonable 

 

18 Id., ¶25. 
No. 2011AP2907-CR.pdr

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officer could have believed that Brown's tail lamp violated 

§ 347.13(1). 

¶115 Accordingly, I would reverse the decision of the court 

of appeals, and I respectfully dissent from the majority 

opinion.

¶116 I am authorized to state that Justice ANNETTE 

KINGSLAND ZIEGLER joins this dissent.
No. 2011AP2907-CR.pdr

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