State v. Flynn, 2011 MT 48

Flynn pled guilty to DUI but reserved right to appeal the stop.
Deputy Lieurance observed Flynn's truck in three lane deviations while traveling ~50 mph on Highway 64 near Big Sky, MT, around 1:30 a.m.
At mile markers 1.7, 1.8, and 2.1, Flynn’s right-side tires crossed the fog line onto the shoulder without apparent road/weather cause.
Lieurance pulled Flynn over after these observations; Flynn was arrested for DUI.
Flynn moved to suppress the stop; the district court denied; Flynn appealed challenging particularized suspicion.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Did the deputy have particularized suspicion to stop Flynn?	Flynn argues crossing the fog line is insufficient for suspicion (cites Lafferty/Morris).	State contends totality of circumstances supports suspicion; Lafferty/Morris flawed; driving suggested impairment.	Yes; the stop was supported by particularized suspicion.

State v. Weer, 358 Mont. 130, 244 P.3d 311 (2010 MT 232) (establishes particularized suspicion framework)
State v. Larson, 358 Mont. 156, 243 P.3d 1130 (2010 MT 236) (limits and applies particularized suspicion standard)
State v. Gopher, 631 P.2d 293 (1981 MT) (early articulation of the standard focusing on officer’s knowledge)
State v. Lafferty, 291 Mont. 157, 967 P.2d 363 (1998 MT 247) (Lock on crossing fog line used to negate suspicion (overruled in later decision))
State v. Morris, 304 Mont. 114, 18 P.3d 1003 (2001 MT 13) (involved driver’s explanation affecting liability but not stop validity)
State v. Clawson, 351 Mont. 354, 212 P.3d 1056 (2009 MT 228) (totality of circumstances assessment for stops)
Lincolnshire v. DiSpirito, 1990 Ill. App. 3d 859, 552 N.E.2d 1238 (1990 IL App 3d) (proper consideration of after-the-fact explanations)
State v. Kinkead, 570 N.W.2d 97 (Iowa 1997) (illustrates subjectivity limits in suspicion analysis)