IA: Mistake of law for stop voids search

Officer’s mistake of law denies the state application of a “good faith exception” to a warrantless stop and seizure. The court declines to follow its own federal circuit because that case law is now undercut and other circuits do not agree. State v. Louwrens, 792 N.W.2d 649 (Iowa 2010):

This case, however, presents a different question: May an officer’s mistake of law provide probable cause to authorize a traffic stop? We mentioned, but did not decide this question in Lloyd. 701 N.W.2d at 680 n.1. A majority of courts that have considered the issue have concluded a mistake of law cannot provide probable cause to justify a traffic stop. See United States v. McDonald, 453 F.3d 958, 962 (7th Cir. 2006); United States v. DeGasso, 369 F.3d 1139, 1144-45 (10th Cir. 2004); United States v. Chanthasouxat, 342 F.3d 1271, 1279 (11th Cir. 2003); United States v. Twilley, 222 F.3d 1092, 1096 (9th Cir. 2000); United States v. Miller, 146 F.3d 274, 279 (5th Cir. 1998).

The State, however, urges us to adopt the minority view held by the Eighth Circuit Court of Appeals. That court has concluded “the legal determination of whether probable cause or reasonable suspicion existed for [a] stop is judged by whether the mistake of law was an ‘objectively reasonable one.’ “ United States v. Washington, 455 F.3d 824, 827 (8th Cir. 2006) (quoting United States v. Smart, 393 F.3d 767, 770 (8th Cir. 2005)).

However, our review of the development of the Eighth Circuit’s position does not convince us to follow suit. In Smart, a case in which the officer “made neither a mistake of law nor one of fact,” the Eighth Circuit stated that “in our circuit the distinction between a mistake of law and a mistake of fact is irrelevant to the fourth amendment inquiry.” 393 F.3d at 769, 770 (citing United States v. Sanders, 196 F.3d 910 (8th Cir. 1999)). However, Sanders, the case cited by the court for this proposition, was not analyzed as a “mistake” case and did not discuss the distinction between a mistake of law and mistake of fact for Fourth Amendment purposes. See Sanders, 196 F.3d at 912-13. It was not until later that year that the Eighth Circuit applied the principle announced in Smart in a case actually involving a mistake of law. United States v. Martin, 411 F.3d 998, 1001 (8th Cir. 2005). It did so without any discussion of the competing view that a mistake of law cannot provide probable cause to justify a traffic stop. In a subsequent decision, the court acknowledged the development of a different rule in other circuits, but did not discuss the rationale supporting that rule. Washington, 455 F.3d at 827 n.1.