While patrolling one night in 2014, police officer Jeff Packard noticed a car with a hole in one of its red taillights.1 The white light bulb inside was visible. Packard believed that Indiana law required a taillight to be red and not to show white light, so he stopped the vehicle. The driver, Kolyann Williams, had drugs with him.2 Williams was charged and convicted with misdemeanor marijuana possession.3 On appeal, Williams argued that, because Indiana law did not in fact prohibit other colors of light from being emitted so long as red light is visible from a certain distance away, the stop was unlawful.4 After examining the statute,5 the Indiana Court of Appeals agreed with Williams and held that the stop violated the Fourth Amendment.6

Shortly after the decision, the US Supreme Court announced in Heien v North Carolina7 that police do not violate the Fourth Amendment when they conduct a search or seizure premised on a mistake of law, so long as the mistake was a reasonable one.8 In light of the Supreme Court’s decision, the state of Indiana asked for and received a rehearing of Williams’s case, and the court reversed itself after applying Heien.9 “A reasonable person unversed in statutory interpretation,” the Indiana court stated, “would very likely” make the mistake of thinking that the statute required that only red light could be emitted by the taillights.10 Officer Packard was mistaken but reasonable, and defendant Williams’s conviction was affirmed.

For many years, the Supreme Court recognized that police officers can have probable cause (sufficient to support a search without violating the Fourth Amendment) even if their suspicion is based on a mistake of fact, so long as the mistake was reasonable.11 Whether the same permissive rule should apply to mistakes of law was a question on which the courts of appeals were split, with the majority of courts nationwide holding that it should not.12 The Supreme Court resolved that issue in 2014, unexpectedly adopting the minority rule when it announced in Heien that a search or seizure based on a reasonable mistake of law is not a Fourth Amendment violation.13

Lower courts have applied Heien inconsistently.14 As it turns out, it is far from self-evident how a court is to recognize when a mistake of law is reasonable. The Court’s opinion in Heien told readers more about what the standard is not than about what it is: the “reasonable mistake” standard is tougher than the standard for qualified immunity.15 This is not very informative.

Some courts have taken a forgiving approach to police mistakes.16 These courts reason more or less as follows: ordinary people make mistakes, and if the law is complex, arcane, or confusing, the police are reasonably likely to get the benefit of the reasonable-mistake rule.17 In other areas of the law, ignorance is sometimes thought to be rational. For example, it might be a rational decision to not read contracts or licenses in full before signing (or clicking “I accept”).18 One might intuitively think that such ignorance is sometimes reasonable. The same intuition could apply in favor of a police officer trying to enforce a complex and confusing statute. Surely one does not expect the police officer to spend the time and effort of a lawyer (or a judge) to figure out what the law means.19 But whatever its intuitive appeal, this approach is in fact quite troubling in the area of police mistakes. Critics of the Heien decision have suggested that the rule in Heien creates unseemly favoritism toward police, according them generosity not accorded to criminal defendants.20 They have suggested that it is in tension with the principle applied in most areas of the law—ignorance of the law is no excuse.21

But not all of the lower courts applying Heien have been so forgiving. Some have held that, when police have made a mistake about the criminal law in deciding that there exists probable cause for a search or seizure, the court should look to that criminal law and decide whether that law is ambiguous.22 For instance, one court suggested that there is “a condition precedent to even asserting that a mistake of law is reasonable,” and that condition is “that the statute be genuinely ambiguous, such that overturning the officer’s judgment requires hard interpretive work.”23 Another court has likewise suggested “that in order for an officer’s mistake of law while enforcing a statute to be objectively reasonable, the statute at issue must be ambiguous.”24

This Comment argues that requiring statutory ambiguity as a precondition to a claim of reasonable mistake is the best way to implement the rule in Heien.25 Further, it argues that the ambiguity analysis should draw on the cases applying the rule of lenity in substantive criminal law. The rule of lenity is a rule of construction that provides that an ambiguous criminal law should be construed in favor of the defendant.26 Courts have applied the rule of lenity rather sparingly in favor of defendants in recent years. Generally, the courts have read a given criminal statute with all the tools of statutory construction at their disposal (including even legislative history as evidence of statutory purpose) in an attempt to resolve the ambiguity before finding that the rule of lenity applied in favor of the defendant.27 This Comment argues that, in the application of the Heien rule, the courts should use the same tools of statutory construction in reading the criminal statute on which the police predicated their search or seizure. Some scholars have suggested that the “reasonable mistake” standard in Heien is in tension with lenity because lenity reads ambiguity in favor of defendants and Heien apparently reads ambiguity in favor of the police.28 This Comment suggests that lenity can actually work in tandem with the Heien rule. By drawing on the rule of lenity, the courts can foster the symmetry between substantive criminal law and the law governing police search and seizure that the Heien majority sought. The rule proposed in this Comment is that Heien should apply (in favor of the police) in any case in which the rule of lenity would be applied (in favor of the defendant) as to the statute on which the search or seizure was predicated. In this manner, the courts can develop the Heien doctrine so as to limit the police discretion about which the Heien decision’s many critics have worried. Because the rule of lenity is applied only in a narrow set of cases, the police will be limited to a very small universe of cases in which they could claim to have reasonably misunderstood the law. Additionally, in order to argue that they reasonably misunderstood a given law, the government will then be put in the position of arguing that a law is so ambiguous that a criminal defendant charged under the law should be acquitted under the rule of lenity. This will presumably lead the state to be cautious about how often it claims the benefit of the Heien rule, lest they establish precedents about the rule of lenity’s application to specific laws that will benefit defendants in future cases.

Part I describes the decision in Heien and the reaction to it from courts and commentators. Part II sketches the doctrines of qualified immunity and the rule of lenity. Part III argues that Heien should carry a statutory ambiguity requirement while Part IV contends that the rule of lenity should be used to guide the ambiguity analysis.

  • 1. Williams v State, 22 NE3d 730, 732 (Ind App 2014) (“Williams I”).
  • 2. Id at 733.
  • 3. Id.
  • 4. Id. The practical goal of this argument was to get all of the evidence collected pursuant to the stop suppressed under the exclusionary rule.
  • 5. The statute allegedly violated was Ind Code § 9-19-6-4, which provides that “a motor vehicle . . . that is registered in Indiana and manufactured or assembled after January 1, 1956, must be equipped with at least two (2) tail lamps mounted on the rear that, when lighted, . . . emit[ ] a red light plainly visible from a distance of five hundred (500) feet to the rear.”
  • 6. Williams I, 22 NE3d at 734.
  • 7. 135 S Ct 530 (2014).
  • 8. Id at 536.
  • 9. Williams v State, 28 NE3d 293, 295 (Ind App 2015) (“Williams II”).
  • 10. Id.
  • 11. See, for example, Illinois v Rodriguez, 497 US 177, 183–86 (1990) (reviewing Fourth Amendment cases on mistake of fact); Brinegar v United States, 338 US 160, 176 (1949) (“Because many situations which confront officers in the course of executing their duties are more or less ambiguous, room must be allowed for some mistakes . . . . But the mistakes must be those of reasonable men.”).
  • 12. Prior to the decision in Heien, the Eighth Circuit held that police mistakes of law could be reasonable. See, for example, United States v Rodriguez-Lopez, 444 F3d 1020, 1022–23 (8th Cir 2006); United States v Martin, 411 F3d 998, 1001 (8th Cir 2005); United States v Smart, 393 F3d 767, 770 (8th Cir 2005). The DC Circuit indicated in dicta that it agreed. See United States v Southerland, 486 F3d 1355, 1359 (DC Cir 2007). The other circuits that considered the issue rejected the argument that a police mistake of law could be reasonable. See United States v Miller, 146 F3d 274, 279 (5th Cir 1998); United States v McDonald, 453 F3d 958, 962 (7th Cir 2006); United States v King, 244 F3d 736, 741 (9th Cir 2001); United States v Nicholson, 721 F3d 1236, 1244 (10th Cir 2013); United States v Chanthasouxat, 342 F3d 1271, 1279–80 (11th Cir 2003). See also Wayne A. Logan, Police Mistakes of Law, 61 Emory L J 69, 74–82 (2011).
  • 13. Heien, 135 S Ct at 534.
  • 14. See Part I.C.
  • 15. Id at 539 (“[T]he inquiry is not as forgiving as the one employed in the distinct context of deciding whether an officer is entitled to qualified immunity.”). Qualified immunity protects officials from civil liability when the official has acted without violating “clearly established” legal rights that a reasonable person would have known about. Mullenix v Luna, 136 S Ct 305, 308 (2015) (per curiam), quoting Pearson v Callahan, 555 US 223, 231 (2009).
  • 16. See, for example, Karen McDonald Henning, “Reasonable” Police Mistakes: Fourth Amendment Claims and the “Good Faith” Exception after Heien, 90 St John’s L Rev 271, 305–08 (2016) (discussing the various ways in which courts have treated police mistakes in a forgiving manner).
  • 17. See, for example, Williams II, 28 NE3d at 295.
  • 18. For rational ignorance in the contract context, see, for example, Shawn J. Bayern, Rational Ignorance, Rational Closed-Mindedness, and Modern Economic Formalism in Contract Law, 97 Cal L Rev 943, 947–49 (2009).
  • 19. This would, presumably, require spending substantial time studying the law, learning how to do legal research in a graduate school context, and then actually conducting research into the meaning of any relevant statute.
  • 20. See, for example, John W. Whitehead, Is Ignorance of the Law an Excuse for the Police to Violate the Fourth Amendment?, 9 NYU J L & Liberty 108, 117–18 (2015).
  • 21. Id.
  • 22. See, for example, Flint v City of Milwaukee, 91 F Supp 3d 1032, 1057 (ED Wis 2015).
  • 23. Id (quotation marks omitted).
  • 24. State v Eldridge, 790 SE2d 740, 743 (NC Ct App 2016).
  • 25. This builds on a suggestion in Justice Elena Kagan’s concurrence, Heien, 135 S Ct at 541 (Kagan concurring), and on an argument in Henning, 90 St John’s L Rev at 307–08 (cited in note 16).
  • 26. See McNally v United States, 483 US 350, 359–60 (1987). See also Albernaz v United States, 450 US 333, 342 (1981) (“[T]he rule of lenity is a principle of statutory construction which applies not only to interpretations of the substantive ambit of criminal prohibitions, but also to the penalties they impose.”).
  • 27. See Note, The New Rule of Lenity, 119 Harv L Rev 2420, 2428–31 (2006).
  • 28. See, for example, Richard H. McAdams, Close Enough for Government Work? Heien’s Less-Than-Reasonable Mistake of the Rule of Law, 2015 S Ct Rev 147, 198–200 (arguing that Heien institutes a “rule of severity” that contrasts with the rule of lenity).