USA v. Demarco L. McDonald, 453 F.3d 958 (7th Cir. 2006)
(Editor’s note: the United States Sureme Court granted cert in Heien v. North Carolina, No. 13-604 on this issue: Whether a police officer’s mistake of law can provide the individualized
suspicion that the Fourth Amendment requires to justify a traffic stop. Cert papers and the decision below can be found here: http://www.scotusblog.com/case-files/cases/heien-v-north-carolina/ ).
Demarco McDonald was arrested for possession of a firearm by a felon, in violation of 18 U.S.C. § 922(g)(1). Police found a gun in his car when they stopped him for using his turn signal while rounding a bend in a street. McDonald contends on appeal that his use of the turn signal was not illegal under Illinois law and that a police officer’s mistaken belief about the law could not support probable cause for his arrest. We agree and therefore reverse the decision of the district court.
Police can stop an automobile when they have probable cause to believe that the driver violated even a minor traffic law. United States v. Muriel, 418 F.3d 720, 724 (7th Cir.2005). Probable cause exists when an officer reasonably believes that a driver committed a traffic offense. Id.
In addition, under Terry v. Ohio, 392 U.S. 1, 30, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968), police may conduct a brief, investigatory traffic stop if they have reasonable suspicion based on articulable facts that a crime is about to be or has been committed. United States v. Baskin, 401 F.3d 788, 791 (7th Cir.2005). A stop and search can be reasonable even if the defendant did not actually commit an offense as long as the officer reasonably believed an offense occurred. United States v. Cashman, 216 F.3d 582, 587 (7th Cir.2000).
The government has not provided any evidence that § 5/11-804(d) was intended to address McDonald’s act of proceeding on the same street after engaging his signal 961*961 at a bend in the road. Officer Pearce was thus mistaken in his belief that McDonald’s conduct violated the law, and now we must consider whether the officer’s erroneously held belief could nonetheless provide probable cause to justify the stop.
It makes no difference that an officer holds an understandable or “good faith” belief that a law has been broken. Whether the officer’s conduct was reasonable under the circumstances is not the proper inquiry. Rather, “the correct question is whether a mistake of law, no matter how reasonable or understandable, can provide the objectively reasonable grounds for providing reasonable suspicion or probable cause.” Id.
The answer is that it cannot. A stop based on a subjective belief that a law has been broken, when no violation actually occurred, is not objectively reasonable. Even though Officer Pearce may have acted in good faith, there is no good faith exception to the exclusionary rule when, as here, an officer makes a stop based on a mistake of law and the defendant is not violating the law.
Finally, we note that the mistake of law at issue here is distinguishable from the circumstances in several cases cited by the government where an officer stopped a defendant based on a reasonable belief about a fact that later turned out to be wrong. See Muriel, 418 F.3d 720; Cashman, 216 F.3d 582; United States v. Dexter, 165 F.3d 1120 (7th Cir.1999); United States v. Smith, 80 F.3d 215 (7th Cir.1996).
Accordingly, the district court’s decision is REVERSED and we REMAND for further proceedings consistent with this opinion.