State v. Bui-Cornethan, 490 P.3d 191

Late at night an informant told police about suspected street-level drug activity near a cul‑de‑sac, identifying a tattooed Hispanic male and others. Officers responded and found HT (matching description) and defendant Tu Fan Bui‑Cornethan (Bui) at the scene.
Officers parked, illuminated the men with headlights/spotlight, approached within ~5 feet, and questioned them; they did not activate emergency lights or siren.
Officers quickly separated the men; HT was frisked and emptied his pockets; Bui voluntarily emptied his pockets and showed his wallet. A search of the area produced only a discarded broken crack pipe.
After about twelve minutes and after Allred had questioned Bui and searched the area, Allred spoke ~90 seconds with backup officer Ruff, who told him Bui had gang history and carried firearms.
Immediately after that exchange Allred asked Bui about weapons, said he would pat him down, and Bui admitted a handgun; officers recovered the gun and charged Bui with firearm offenses.
The district court denied Bui’s suppression motion (finding a consensual encounter or, alternatively, lawful stop and scope). Bui entered a conditional guilty plea reserving appeal; the Court of Appeals reversed, holding the encounter was a level two stop and the detention was unlawfully extended.

Issue	Plaintiff's Argument (State)	Defendant's Argument (Bui)	Held
Whether the officers’ interaction was a consensual (level one) encounter or a seizure (level two)	Interaction was consensual or, alternatively, officers had reasonable suspicion to detain based on the informant tip	The encounter was a seizure (level two) because presence of multiple officers, illumination, separation, direction to wait, and accusatory questioning would make a reasonable person feel not free to leave	Court: It was a level two stop (seizure).
Whether the detention/search was lawful in scope or unlawfully extended after initial suspicion was dispelled	Continued questioning and Ruff’s input were part of investigating reported drug activity and did not unlawfully prolong the stop	Any reasonable suspicion of drug activity was dispelled by the questioning, area search, and emptying of pockets; the 90‑second exchange with Ruff was unrelated and unlawfully extended the stop, rendering the subsequent weapons search unlawful	Court: Even if initial detention was justified, it was unlawfully extended after suspicion was dispelled; suppression required.

Terry v. Ohio, 392 U.S. 1 (establishes stop‑and‑frisk reasonableness standard)
United States v. Mendenhall, 446 U.S. 544 (consensual encounter vs seizure test)
Rodriguez v. United States, 575 U.S. 348 (on limits of stop scope and impermissible detours)
State v. Alverez, 147 P.3d 425 (Utah 2006) (framework for three encounter levels)
State v. Hansen, 63 P.3d 650 (Utah 2002) (stop purpose conclusion and end‑of‑stop rule)
State v. Chism, 107 P.3d 706 (Utah App. 2005) (continuing detention after suspicion dispelled is unlawful)
State v. Simons, 296 P.3d 721 (Utah 2013) (de minimis extensions and stop conclusion principle)
State v. Adams, 158 P.3d 1134 (Utah App. 2007) (factors converting consensual questioning to a seizure)