Mitchell v. United States, 314 A.3d 1144

MPD officers responded to a ShotSpotter alert indicating a single gunshot near 2316 4th Street NE, DC, on September 10, 2018, but heard no gunfire themselves and received no 911 calls or suspect descriptions.
Officers saw Maurice Mitchell biking away from the general area of the alert, dressed in dark clothing and a hood, and wearing a face mask that did not obscure his features.
When Mitchell saw the officers, he appeared to flinch and increased his biking speed, which officers interpreted as nervousness or evasiveness.
Officers followed and stopped Mitchell near the Edgewood Apartments, activated emergency lights, shouted commands, and observed a firearm in his bag before arresting him.
Mitchell moved to suppress the firearm as evidence, arguing the stop was without reasonable suspicion; the trial court denied the motion, leading to his conviction and subsequent appeal.
The appellate court reviewed whether reasonable, articulable suspicion justified the stop and seizure under the Fourth Amendment.

Issue	Mitchell's Argument	Government's Argument	Held (Court's Ruling)
Whether officers had reasonable suspicion to stop Mitchell	No particularized suspicion; proximity/dress/behavior were innocuous	Reasonable suspicion existed based on proximity, appearance, and behavior	No reasonable suspicion; factors not sufficiently probative of criminal conduct
Whether the discovery of the firearm should be suppressed	Evidence was fruit of unlawful stop	Stop was lawful, so evidence admissible	Suppression motion should have been granted; evidence excluded
Effect of temporal/geographic proximity to a ShotSpotter alert	Presence near alert not enough for individualized suspicion	Proximity and timing justified focusing on Mitchell	Proximity alone not probative; too large universe of potential suspects
Whether nervousness/fleeing, attire, or biking route supported suspicion	Conduct and dress were consistent with innocent explanations	Flinching, dress, and route were indicative of evasiveness	Such factors, without more, are too ambiguous to support a stop

Alabama v. White, 496 U.S. 325 (reasonable suspicion is a less demanding standard than probable cause)
Illinois v. Wardlow, 528 U.S. 119 (nervous, evasive behavior is a pertinent factor in determining reasonable suspicion)
United States v. Arvizu, 534 U.S. 266 (reasonable suspicion must be based on totality of circumstances)
Florida v. Bostick, 501 U.S. 429 (seizure occurs when a reasonable person would not feel free to leave)
Michigan v. Chesternut, 486 U.S. 567 (reasonable person standard does not vary with individual approached)
Brendlin v. California, 551 U.S. 249 (seizure by show of authority requires submission)