Stopping a vehicle is a seizure under the Fourth Amendment.  Under Terry v. Ohio the U.S. Supreme Court permits a brief investigative stop where there is reasonable suspicion to believe the person is engaged in criminal activity. All that is necessary is reasonable suspicion that the person is engaged in criminal activity.  A Terry stop requires particularized suspicion of criminal activity.  Police must be able to point to specific and articulable facts which, taken together with rational inferences from those facts, reasonably warrants that intrusion (stop).


  1. Investigate a traffic violation:● DTCD – disregarding a stop sign, traffic signal
  2. ● Equipment violation
  3. ● Speeding
  4. Suspicion of criminal activity. Terry allows for investigative stop.
  5. Anonymous tip.

Police may make traffic stops based on a citizen reports, U.S. v. Watts, 7 F.3d. 122.

U.S. v. Jackson, 918 F.2d. 236

U.S. v. Ridge, 329 F.3d. 539 (6th circuit)

U.S. v. Hensley, 469 U.S. at 229

Traffic Stop:  Turley v. Commonwealth (2011)

Holding – Once purpose of traffic stop has concluded any follow up conversation between police and detainee is presumed to be custodial except when it is clearly shown to be initiated by the motorist alone.  You must establish that the purpose of the original stop had ended and the defendants were free to leave.  Questions unrelated to the original stop are permissible only if the cop has objectively reasonable and articulable suspicion of illegal activity.