In Washington random, suspicionless stops are unlawful. See, e.g., City of Seattle v. Mesiani, 110 Wash.2d 454, 755 P.2d 775 (1988). The officer must have reasonable suspicion that criminal activity is afoot prior to making a traffic stop. See Delaware v. Prouse, 440 U.S. 648, 99 S.Ct. 1391 (1979); State v. Kennedy, 107 Wash.2d 1, 726 P.2d 445 (1986). In 2012, the Washington Supreme Court also opined that reasonable suspicion of a traffic infraction is also sufficient to justify a traffic stop. State v. Snapp, 174 Wash.2d 177, 275 P.3d 289 (2012). Nevertheless, the validity of the traffic stop should be scrutinized in every DUI case.

During the vehicle in motion phase of DUI detection, officers are trained to look for moving violations, an equipment violation, expired registration, evidence of drinking or drugs in vehicles, or unusual driving behaviors. Specific visual cues that officers look for include weaving, crossing or straddling a lane line, swerving, turning with a wide radius, drifting, stopping short or beyond stop lines, stopping abruptly or with a jerk, rapid acceleration or deceleration, varying speeds, slow speeds. However, such visual cues may not necessarily be sufficient to justify a vehicle stop in all cases. For example, a minor incursion over a lane line might not provide a sufficient basis to stop a vehicle. See, e.g., United States v. Colin, 314 F.3d 439 (9th Cir. 2002); State v. Archuleta, 160 Wash.App. 1031 (2011) (unpublished opinion); State v. Prado, 144 Wash.App. 227, 181 P.3d 901 (2008). Other visual cues officers have been trained to look for may also not give rise to reasonable suspicion. There are countless other reasons why a stop may be unlawful. Overall, it is important to scrutinize the validity of the vehicle stop. If an initial vehicle stop is unlawful the fruits (results) of the subsequent DUI investigation will be inadmissible. See State v. Kennedy, 107 Wash.2d 1, 726 P.2d 445 (1986) (citing Wong Sun v. United States, 371 U.S. 471, 83 S.Ct 407 (1963)); see, e.g., Campbell v. State of Wash. Dept. of Licensing, 31 Wash.App. 833, 644 P.2d 1219 (1982).

Driving behaviors are important to evaluate in DUI cases for purposes beyond the legal sufficiency of the stop. “Good driving” behaviors may undermine the allegation of driver impairment and may indicate sobriety. “Bad driving” behaviors may occur for reasons other than drug or alcohol consumption and may otherwise be explained.

DUI requires driving “within this state.” RCW 46.61.502(1). At times officers may arrest individuals who are driving under the influence, but not on or near public roads. This might not be sufficient to support a DUI charge. See, e.g., State v. Day, 96 Wash.2d 646, 638 P.2d 546 (1981). We see such cases on Whidbey Island, where there is room to roam off of the public roads.

Other times officers may arrest an intoxicated person for DUI when the officer did not witness the person driving. The officer may simply rely on the intoxicated person’s admission that he or she had been driving. This scenario oftentimes arises when officers respond to the scene of an accident. In Washington a defendant’s incriminating statement alone is not sufficient to establish the “corpus delicti” of DUI (i.e. “body of the crime”). The prosecution must present evidence independent of the incriminating statement. State v. Aten, 130 Wash.2d 640, 655-56 (1996). An intoxicated person’s admission to driving, without more, should not be sufficient to convict him or her of DUI. See, e.g., State v. Hamrick, 19 Wash.App. 417, 419 (Wash. Ct. App. 1978).