Deandre J. Posey v. United States, 201 A.3d 1198

Officers received two radio lookouts reporting an armed robbery: suspect described only as a "black male dressed in all black," and later that a group of black males was seen heading toward North Capitol Street.
Officers Kasco and Orgel arrived on the unit block of M Street within minutes and saw a group of five or more black males, mostly in black jackets, walking toward North Capitol; Sergeant Ritchie and the complainant were already on scene.
Kasco drove within about 15 feet of the group; the group briefly stopped and looked at the marked cruiser. Kasco observed no illegal activity or furtive movements by Posey or others before Posey ran.
Officer Orgel chased and apprehended Posey; Kasco conducted a Terry pat-down and seized a handgun from Posey’s waistband. Posey was not identified as the robber in a subsequent show-up.
The trial court denied Posey’s motion to suppress, concluding officers had reasonable articulable suspicion because Posey matched the vague lookout, was near the scene shortly after the report, and fled when approached.
On stipulation of the facts regarding the gun, Posey was convicted of multiple weapons offenses; the convictions were stayed pending appeal.

Issue	Posey’s Argument	Government’s Argument	Held
Whether officers had reasonable articulable suspicion to stop Posey under Terry after approaching a group matching a vague description and Posey’s unprovoked flight	The vague lookout (race and clothing) plus mere presence in the group and subsequent flight did not produce particularized suspicion to stop Posey	The proximity in time/place to the reported robbery, the group matching the lookout in a predominately Black neighborhood, and Posey’s flight justified a stop (citing Wardlow)	Court held there was no reasonable, particularized suspicion; the stop was unlawful and the gun must be suppressed, requiring reversal of convictions

Terry v. Ohio, 392 U.S. 1 (1968) (establishing investigatory stop standard)
Illinois v. Wardlow, 528 U.S. 119 (2000) (discussing flight in a high-crime area as a factor in reasonable suspicion)
Navarette v. California, 572 U.S. 393 (2014) (assessing reasonable suspicion from reported facts)
Armstrong v. United States, 164 A.3d 102 (D.C. 2017) (cautioning against supporting stops on generalized descriptions)
Pridgen v. United States, 134 A.3d 297 (D.C. 2016) (requiring development of investigatory facts beyond an initial hunch)
Jackson v. United States, 157 A.3d 1259 (D.C. 2017) (describing step-by-step investigation needed to justify a stop)