People v. McDonough, 239 Ill. 2d 260

On Oct. 10, 2008, ~7:30 p.m., Trooper Brunnworth on SR 100, east of Grafton, found a car stopped on the shoulder with headlights off.
Brunnworth approached, activated emergency lights for safety; driver was McDonough, passenger his wife; no weapons observed.
Brunnworth detected a breath odor of alcohol shortly after the approach; defendant admitted drinking three drinks.
Defendant performed some field sobriety tests but refused the Breathalyzer; arrest followed; police report mentioned open alcohol.
Defendant moved to suppress evidence and quash arrest; circuit court granted; State appealed; appellate court reversed; Supreme Court granted leave to appeal.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Brunnworth’s emergency-light activation caused a seizure.	People contends seizure occurred but was justified as community caretaking.	McDonough argues no seizure or improper conduct; rights violated.	seizure occurred but justified under community caretaking; no exclusionary rule needed.
Whether the community caretaking seizure was reasonable under the Fourth Amendment.	People maintains objective facts show safety/public concerns warrant seizure.	McDonough argues seizure is outside Fourth Amendment bounds.	seizure upheld as reasonable under community caretaking; no fourth-amendment violation.

Whren v. United States, 517 U.S. 806 (U.S. 1996) (stop reasonable with probable cause; exceptions exist for reasonableness)
Cady v. Dombrowski, 413 U.S. 433 (U.S. 1973) (community caretaking functions separate from crime investigation)
Luedemann v. State, 222 Ill.2d 530 (Ill. 2006) (community caretaking distinct from consensual encounters; two criteria)
Ohio v. Robinette, 519 U.S. 33 (U.S. 1996) (reasonableness assessed by totality of circumstances)