D.D.C.: Flight from a potential encounter in a high crime area is RS; detention after that was reasonable based on collective knowledge

Flight from a potential encounter in a high crime area is reasonable suspicion. Detention after that was reasonable based on collective knowledge. The court also addresses at length vertical and horizontal collective knowledge and follows the Fourth Circuit rule that is based on Hensley and promotes promptness and efficiency. United States v. Gorham, 2018 U.S. Dist. LEXIS 131088 (D.D.C. Aug 05, 2018) (yes, filed on Sunday):

Those courts of appeals that have confronted the issue are divided. The First, Third, and Seventh Circuits have held that information may be aggregated “horizontally” among officers working closely together even absent evidence of a communication or directive. …

The Fifth, Sixth, Eighth, Ninth, and Eleventh Circuits have also permitted the aggregation of knowledge “regardless of whether any information giving rise to probable cause was actually communicated to the officer conducting the stop, search, or arrest,” albeit only when the officers are working as a team, as evidenced by some “communication among agents.” …

The Second, Fourth, and Tenth Circuits, in contrast, have categorically rejected the “horizontal” collective knowledge doctrine. …

On this question of first impression in this circuit, the Court finds the reasoning of the Fourth Circuit in United States v. Massenburg persuasive. The Fourth Circuit observed in that case that “[t]he rationale behind the Supreme Court’s collective-knowledge doctrine is, as the Court noted in Hensley, ‘a matter of common sense: [the rule] minimizes the volume of information concerning suspects that must be transmitted to other jurisdictions [or officers] and enables police … to act promptly in reliance on information from another jurisdiction [or officer].'” Massenburg, 654 F.3d at 494 (quoting Hensley, 469 U.S. at 231). Under this “vertical” understanding of the collective knowledge doctrine, “law enforcement efficiency and responsiveness [is] increased,” id., and individual officers are allowed to rely on the implicit representation from their colleagues that sufficient grounds exist for the search or seizure. In this sense, the executing officers are acting as the agents or proxies of, or are relying on information provided by, the officers who possess probable cause or reasonable suspicion.