State v. Richard Glenn Morris, 365 P.3d 407

Officer followed Morris a few car lengths on a residential street and observed Morris’ passenger‑side tires fully cross a solid white line (into a bike lane or parking area) for 2–3 seconds. Neither officer nor Morris perceived any need to leave the lane at that time.
Officer pulled Morris over, smelled marijuana while approaching the vehicle, and requested a drug dog; the dog alerted to a purse on the passenger floorboard containing nearly one-half pound of marijuana.
Morris told the officer he was on probation; a probation officer was contacted; Morris and his passenger were arrested and Morris was charged with possession of marijuana with intent to deliver (later convicted of the lesser included misdemeanor possession).
Morris moved to suppress evidence, arguing the stop lacked reasonable suspicion and disputing the factual finding that his tires crossed the solid white line; the district court found the officer credible and denied the motion.
On appeal, the Court of Appeals reviewed the district court’s factual findings for substantial evidence and reviewed legal conclusions de novo, and affirmed the denial of the suppression motion.

Issue	Plaintiff's Argument (State)	Defendant's Argument (Morris)	Held
Whether there was substantial evidence to support the district court’s factual finding that Morris’ tires crossed the solid white line	Officer’s testimony (direct observation from a few car lengths), corroborated by the officer telling Morris at the stop, was credible and sufficed as substantial evidence	Officer’s testimony was inaccurate in parts and not sufficiently reliable to support the finding that the tires crossed the solid white line	Court held there was substantial evidence; trial court credibility determinations are entitled to deference and supported the finding
Whether the stop was supported by reasonable suspicion under the Fourth Amendment and I.C. § 49-637(1)	Crossing a solid white line into a bike lane/parking area when it was practicable to remain in the lane constituted a traffic violation, giving reasonable suspicion to stop	The brief lane crossing fell within normal driving behavior and did not amount to a violation or reasonable suspicion	Court held the crossing (with no exigent circumstance making staying in lane impracticable) violated I.C. § 49-637(1) and provided reasonable suspicion to stop

Delaware v. Prouse, 440 U.S. 648 (Fourth Amendment seizure rule regarding police stops of vehicles)
United States v. Cortez, 449 U.S. 411 (totality of circumstances standard for reasonable suspicion)
United States v. Arvizu, 534 U.S. 266 (reasonable suspicion for investigative stops need not identify particular offense)
State v. Atkinson, 128 Idaho 559 (standard of review for suppression rulings: defer to factual findings)
State v. Perez-Jungo, 156 Idaho 609 (reasonable suspicion standard for traffic stops)
State v. Emory, 119 Idaho 661 (facts that fall within range of normal driving do not automatically create reasonable suspicion)