State Of Washington v. Shane Ahearn, 46645-7

At 3:15 AM on Feb. 2, 2014, Trooper Kyle Dahl observed Shane Ahearn swerving within lanes, crossing the fog line, failing to stop at an exit stop sign, and turning without signaling; Ahearn delayed pulling over after lights were activated.
On contact Ahearn was profusely sweating, spoke fast and brokenly, had watery/bloodshot eyes, struggled with simple vehicle/jacket tasks, stumbled, and exhibited violent body tremors and circular swaying.
Trooper Dahl administered field sobriety tests: HGN (zero clues), walk-and-turn (questionable performance on a sloped surface), one-leg stand (poor performance), and a Romberg-type balance/time test (approx. 34s); portable breath test read .000.
Trooper Dahl concluded the signs suggested stimulant influence and arrested Ahearn for DUI; after consent to search, officer found a syringe containing methamphetamine in the vehicle.
Ahearn moved to suppress evidence, arguing lack of probable cause; after a suppression hearing the court denied suppression. Ahearn then waived jury and stipulated to facts for a bench trial and was convicted of DUI (driving while ability impaired by drug) and unlawful possession of a controlled substance.

Issue	Ahearn's Argument	State's Argument	Held
Whether Trooper Dahl had probable cause to arrest for DUI	Trooper Dahl lacked probable cause; observed signs had alternative explanations (time of night, cold, fatigue); some tests were invalid due to slope	Totality of observations (driving, behavior, tremors, sweating, attention deficits, field tests) provided probable cause	Probable cause existed; denial of suppression affirmed
Whether body tremors/sweating could be credited as signs of drug impairment	Tremors could be from cold/sweating and not indicative of stimulant use	Trooper’s training/experience supported that severity of tremors, plus other signs, pointed to stimulant influence	Trial court reasonably credited trooper’s testimony; tremors were properly considered
Sufficiency of evidence to convict of DUI by drugs	Evidence insufficient: no blood test or drug-recognition expert; field tests invalid or equivocal; syringe presence alone insufficient	Circumstantial proof OK: driving impairment, physical signs, and methamphetamine in vehicle together support drug-impaired driving	Evidence was sufficient beyond a reasonable doubt; convictions affirmed
Whether trial court erred in findings re: stimulant inference	Finding that signs "suggested" stimulant use not supported in written report	Other unchallenged findings (impairment + drugs in car) supply basis for conclusion	Any error was harmless; overall findings support conclusion of drug-impaired driving

State v. Cole, 122 Wn. App. 319 (court reviews suppression findings for substantial evidence)
State v. Mendez, 137 Wn.2d 208 (standard for reviewing suppression rulings)
State v. Grande, 164 Wn.2d 135 (probable cause legal question reviewed de novo)
State v. Terrovona, 105 Wn.2d 632 (definition of probable cause)
State v. Fricks, 91 Wn.2d 391 (probable cause depends on totality of circumstances)
State v. Conner, 58 Wn. App. 90 (probable cause need not establish guilt beyond reasonable doubt)
State v. Chamberlin, 161 Wn.2d 30 (treatment of findings vs. conclusions on appeal)
State v. Stevenson, 128 Wn. App. 179 (bench-trial sufficiency and review standards)
State v. Salinas, 119 Wn.2d 192 (standard for sufficiency review)
State v. Myers, 133 Wn.2d 26 (circumstantial evidence can support findings)
State v. Woolbright, 57 Wn. App. 697 (chemical tests not required to prove intoxication)