State v. Chacon Arreola173 Wn.2d 1013, 272 P.3d 246 (2012).

On October 10, 2009, an officer got an uncorroborated report of DUI.  When the officer arrived, he located a vehicle matching the description from the report. The officer followed behind the vehicle for approximately half of a mile.  The officer did not see evidence of DUI.  However, the officer did note an exhaust violation.  After pulling the driver over he noted the signs of impairment.  

At trial the officer acknowledged his primary motivation was the DUI investigation. The defense argued this was a pretextual stop.  

On appeal, the Court of Appeals upheld the trial court’s findings of fact from the suppression hearing but disagreed with the trial court’s resulting conclusion that the traffic stop was constitutional. Chacon Arreola, 163 Wn. App. at 796-97. The Court of Appeals acknowledged that the muffler infraction was an actual reason for the stop but held that because “it was clearly subordinate to the officer’s desire to investigate the DUI report,” and “only a secondary reason,” the muffler infraction could not provide authority of law for the traffic stop. Id. at 797. The State petitioned this court for review of that purely legal issue, and the State Supreme Court granted the petition for review. State v. Chacon Arreola173 Wn.2d 1013, 272 P.3d 246 (2012).

Warrantless traffic stops are constitutional under article I, section 7 of the Washington Constitution as investigative stops, but only if based upon at least a reasonable articulable suspicion of either criminal activity or a traffic infraction, and only if reasonably limited in scope. See Ladson, 138 Wn.2d at 350, 351-52 (citing Terry v. Ohio, 392 U.S. 1, 88 S. Ct. 1868, 20 L. Ed. 2d 889 (1968)); RCW 46.61.021(2); see also Snapp, 174 Wn.2d at 197-98; State v. Doughty170 Wn.2d 57, 62, 239 P.3d 573 (2010); Day, 161 Wn.2d at 896; Duncan, 146 Wn.2d at 173-74; cf. State v. Nichols161 Wn.2d 1, 13, 162 P.3d 1122 (2007) (warrantless traffic stop is constitutional if based upon probable cause that a traffic infraction occurred). The narrow exception to the warrant requirement for investigative stops has been extended beyond criminal activity to the investigation of traffic infractions because of “‘the law enforcement exigency created by the ready mobility of vehicles and governmental interests in ensuring safe travel, as evidenced in the broad regulation of most forms of transportation.'” Day, 161 Wn.2d at 897 (quoting State v. Johnson128 Wn.2d 431, 454, 909 P.2d 293 (1996)); Duncan, 146 Wn.2d at 174.

Pretextual traffic stops are unconstitutional under article I, section 7. See Ladson, 138 Wn.2d at 358; see also Snapp, 174 Wn.2d at 199; Nichols, 161 Wn.2d at 8-9. A pretextual traffic stop occurs when a police officer relies on some legal authorization as “a mere pretext to dispense with [a] warrant when the true reason for the seizure is not exempt from the warrant requirement.” Ladson, 138 Wn.2d at 358. Because the right to privacy in such cases is disturbed without reasonable necessity and only in furtherance of some illegitimate purpose, pretextual stops “are seizures absent the ‘authority of law'” required by article I, section 7. Id. (quoting CONST. art. I, $ 7).

A mixed-motive stop does not violate article I, section 7 as long as the police officer making the stop exercises discretion appropriately. Thus, if a police officer makes an independent and conscious determination that a traffic stop to address a suspected traffic infraction is reasonably necessary in furtherance of traffic safety and the general welfare, the stop is not pretextual.

That remains true even if the legitimate reason for the stop is secondary and the officer is motivated primarily by a hunch or some other reason that is insufficient to justify a stop. In such a case, the legitimate ground is an independent cause of the stop, and privacy is justifiably disturbed due to the need to enforce traffic regulations, as determined by an appropriate exercise of police discretion. Any additional reason or motivation of the officer does not affect privacy in such a case, nor does it interfere with the underlying exercise of police discretion because the officer would have stopped the vehicle regardless. The trial court should consider the presence of an illegitimate reason or motivation when determining whether the officer really stopped the vehicle for a legitimate and independent reason (and thus would have conducted the traffic stop regardless). But a police officer cannot and should not be expected to simply ignore the fact that an appropriate and reasonably necessary traffic stop might also advance a related and more important police investigation. Cf. Nichols, 161 Wn.2d at 11 (“‘[E]ven patrol officers whose suspicions have been aroused may still enforce the traffic code . . . .'” (quoting State v. Minh Hoang101 Wn. App. 732, 742, 6 P.3d 602 (2000)). In such a case, an officer’s motivation to remain observant and potentially advance a related investigation does not taint the legitimate basis for the stop, so long as discretion is appropriately exercised and the scope of the stop remains reasonably limited based on its lawful justification.

The Supreme Court held that a mixed-motive traffic stop is not pretextual so long as the desire to address a suspected traffic infraction (or criminal activity) for which the officer has a reasonable articulable suspicion is an actual, conscious, and independent cause of the traffic stop. As long as a police officer actually, consciously, and independently determines that a traffic stop is reasonably necessary in order to address a suspected traffic infraction, the stop is not pretextual in violation of article I, section 7, despite other motivations for the stop.