State v. R. Kelm, 2017 MT 113N

On April 25, 2015 at about midnight, Sgt. Jesse Jessop observed Richard Kelm weaving within his traffic lane while traveling south on Highway 93 in Hamilton, Montana.
After a few seconds, Kelm turned into the Albertsons parking lot (a closed business) and then slowly drove toward and parked near the entrance of the adjacent K‑Mart (also closed), a location that had experienced numerous after‑hours alarms.
Sgt. Jessop followed, then initiated an investigative stop based on the weaving, the late hour, the quick turn into a closed business after being observed, and Kelm’s slow driving near the closed K‑Mart.
The stop developed into a DUI investigation; Kelm moved to suppress evidence and dismiss the charge in Justice Court, which was denied. He pleaded guilty but reserved the right to appeal the suppression denial to district court under § 46‑12‑204(3), MCA.
The District Court affirmed the justice court; Kelm appealed to the Montana Supreme Court arguing the stop lacked particularized suspicion.
The Supreme Court reviewed under the clearly‑erroneous/constitutional standard and affirmed the District Court’s conclusion that Sergeant Jessop had particularized suspicion to stop Kelm.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the officer had particularized suspicion to conduct an investigative stop.	Weaving within lane, late hour, abrupt turn into closed businesses after being observed, and slow driving near a location with recent alarms justified reasonable, particularized suspicion.	The facts (lane weaving and presence in closed parking lot) did not supply particularized suspicion to justify an investigative stop.	The totality of circumstances (weaving, time of night, turning into closed business, driving near a problem‑prone K‑Mart) gave the officer the requisite particularized suspicion; stop affirmed.

State v. Loiselle, 30 P.3d 1097 (discussing standard of review for suppression findings)
State v. Dupree, 346 P.3d 1114 (clarifying clearly erroneous standard for factual findings)
State v. Wagner, 303 P.3d 285 (weaving within a lane can indicate impairment)
State v. Clark, 218 P.3d 483 (State bears burden to show sufficient facts for particularized suspicion)
State v. Flynn, 251 P.3d 143 (observing a traffic offense is sufficient but not necessary for suspicion)
State v. Cameron, 264 P.3d 1136 (totality of circumstances approach to stops)
State v. Pratt, 951 P.2d 37 (considering time, location, and driving in totality of circumstances)
Weer v. State, 244 P.3d 311 (time of day and driving behavior are permissible factors in suspicion analysis)