State v. Morris, 2011 UT 40

Morris was stopped at night on a two-lane Utah highway after Trooper Williams observed the car allegedly lacking a current license plate.
The stop was initiated based on an objectively reasonable belief of a traffic violation (no current plate) before the officer confirmed a valid temporary tag.
As the stop began, the officer discovered a valid temporary registration tag but still approached the vehicle and spoke with Morris.
The officer detected a fresh cigar odor and, through it, the smell of alcohol, prompting field sobriety tests and an arrest for DUI.
The district court denied suppression; the court of appeals reversed, leading to the Utah Supreme Court’s certiorari to resolve the post-suspicion conduct during a previously justified stop.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the stop was justified at inception	Morris: the initial basis dissipated once the tag appeared, making any contact unlawful.	State: stop was justified at inception based on an objective belief of a violation.	Yes, stop justified at inception.
Whether officer may approach to explain a mistaken basis	Morris: approaching to explain mistake violates Fourth Amendment and cannot occur.	State: officer may briefly explain mistake to end the stop.	Yes, officer may approach to explain and end the stop.
Whether new odor of alcohol justifies further detention	Morris: no new suspicion arose to justify further detention after the explanation.	State: odor of alcohol creates new reasonable suspicion.	Yes, odor of alcohol justified further detention.
Scope of the brief encounter and permissible inquiries	Morris: even brief contact cannot solicit identification/registration.	State: brief contact permissible; no requests unless new suspicion arises.	Brief encounter limited; May not request docs unless new specific facts showing risk arise.

State v. Baker, 229 P.3d 650 (Utah 2010) (two-part test for traffic stops; reasonableness at inception and scope)
State v. Applegate, 194 P.3d 925 (Utah 2008) (reasonableness standard for traffic stops; scope tied to purpose)
United States v. Jenkins, 452 F.3d 207 (2d Cir. 2006) (reasonable mistake may lead to initial contact; odor later provides basis for detention)
United States v. McSwain, 29 F.3d 558 (10th Cir. 1994) (reasonableness is the touchstone of the Fourth Amendment stop)
State v. Markland, 112 P.3d 507 (Utah 2005) (reasonable suspicion standard; supports dual inquiry)
State v. Roybal, 232 P.3d 1016 (Utah 2010) (reasonable suspicion and scope considerations in stops)
Lopez v. Utah, 873 P.2d 1127 (Utah 1994) (articulable facts and reasonable suspicion standard)