Officer Vanterpool's stop was an unreasonable seizure without probable cause; D.C. Court of Appeals affirmed, evidence suppressed.

1) The question: Did Officer Vanterpool violate the Fourth Amendment by seizing R.W. without a warrant or probable cause, based on a dispatch, flight by companions, late hour, and backing car with open door? 2) Relevant text: Fourth Amendment: 'The right of the people to be secure in their persons... against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.' Tenth Amendment reserves unenumerated powers like local policing to states/D.C. 3) Ratification-era understanding (1787-1791): 'Seizure' meant control of person/property akin to arrest; required probable cause (reasonable belief of crime) or warrant; barred arbitrary stops by customs officers via writs of assistance; constables acted only on felonies in view, hot pursuit, or breach of peace—no generalized 'suspicion' stops; Framers rejected lesser intrusions to protect liberty. 4) Holding: No probable cause here (no known crime, just odd behavior); ordering hands up while drawing gun was seizure, unreasonable without cause/warrant; suppress evidence, vacate adjudication/probation; Tenth Amendment lets D.C. Council enact rules if text-compliant. 5) Downstream changes: Ends Terry stops nationwide; police limited to consensual talks, probable cause arrests, or warrants; boosts personal security, cuts pretextual policing; invites state experiments (e.g., D.C. probable cause lite via statute, Tenth Amendment).