People v. Cummings, 6 N.E.3d 725

On Jan. 27, 2011, Derrick Cummings was stopped in a van registered to Pearlene Chattic after Officer Bland discovered Chattic had an outstanding arrest warrant. Bland could not initially see the driver’s face.
After pulling alongside at a stop sign and following a short distance, Bland activated his lights, approached, and determined the driver was a man (not Chattic). He then asked Cummings for his driver’s license and proof of insurance.
Cummings had no license; he was cited for driving on a suspended license. He moved to suppress evidence, arguing the officer unlawfully prolonged the stop by requesting identification after the original justification evaporated.
The trial court granted suppression; the appellate court affirmed, holding that once Bland determined the driver was not Chattic, any reasonable suspicion dissipated and further detention to request credentials was unconstitutional.
The Illinois Supreme Court affirmed the appellate court: because the request for Cummings’s license was unrelated to the already-resolved purpose of the stop (identifying Chattic), it impermissibly prolonged the seizure and violated the Fourth Amendment.

Issue	State's Argument	Cummings' Argument	Held
Whether officer lawfully requested driver’s license after the initial raison d’être for the stop dissipated	Requesting license is routine, minimally intrusive, tied to statutory duties, and permissible as an ordinary inquiry during a traffic stop	Once officer saw driver was not the person with the warrant, reasonable suspicion evaporated and any further detention to request ID was unlawful	Court held request impermissibly prolonged the stop and violated the Fourth Amendment; suppression affirmed

Illinois v. Caballes, 543 U.S. 405 (2005) (a lawful stop can become unlawful if prolonged beyond time needed to complete its mission; ordinary inquiries incident to a stop may be permissible)
Delaware v. Prouse, 440 U.S. 648 (1979) (random stops to check licenses violate the Fourth Amendment absent particularized suspicion)
Terry v. Ohio, 392 U.S. 1 (1968) (brief investigatory stops permitted if reasonably justified and limited in scope)
People v. Harris, 228 Ill. 2d 222 (Ill. 2008) (traffic-stop duration must be tied to the stop’s purpose; stop becomes unlawful if prolonged)
United States v. McSwain, 29 F.3d 558 (10th Cir. 1994) (holding further questioning exceeded the scope once the stop’s purpose was satisfied; relied on by majority)