People v. Thomas, 2016 IL App (1st) 141040

On Sept. 15, 2009, two plainclothes Chicago officers were flagged down in person by an unidentified man who said a black male in a red shirt had placed a handgun into a backpack and was walking east on 80th Place.
Within about a block and a half the officers located defendant Lamont Thomas matching that description holding a backpack; officers announced and moved to detain/pat down him on a front porch.
As an officer reached for Thomas’s waistband the backpack hit the porch with a “thud”; a struggle ensued, the officers opened the pack and recovered a loaded revolver and ammunition.
Thomas was later arrested (after being detained again in 2011), charged with AUUW and UUW counts, and convicted at a bench trial of unlawful use/possession of a weapon by a felon; sentenced to five years.
Thomas moved to quash arrest and suppress; trial court denied the motion, finding the in-person tip sufficiently reliable and predictive to justify a Terry stop; this court reversed.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether officers had reasonable, articulable suspicion to conduct a Terry stop based on the in-person anonymous tip that defendant had a gun	Tip was reliable: face-to-face informant, officer observed matching suspect and direction of travel, corroboration within seconds justified a stop	Tip was anonymous/unverified and insufficient to supply reasonable suspicion; stop was unlawful	Stop was initially justifiable under the then-valid AUUW statute, but post-Aguilar the statute is void ab initio, so no valid basis exists now; stop violated defendant’s Fourth Amendment rights
Whether evidence (gun) seized after the stop is admissible despite later invalidation of the statute	State argued officers acted under the law prevailing at the time and good-faith exception should permit admission	Defendant argued exclusionary rule bars evidence obtained from enforcement of a statute later held void ab initio	Good-faith exception rejected under Illinois void ab initio jurisprudence; evidence suppressed

Terry v. Ohio, 392 U.S. 1 (establishes standard for investigative stops requiring reasonable, articulable suspicion)
Illinois v. Krull, 480 U.S. 340 (good-faith exception where officers reasonably rely on statute later invalidated)
United States v. Calandra, 414 U.S. 338 (exclusionary rule purpose and scope)
Weeks v. United States, 232 U.S. 383 (root of the exclusionary rule)
Mapp v. Ohio, 367 U.S. 643 (exclusionary rule applied to states)
Michigan v. DeFillippo, 443 U.S. 31 (later-invalidated statute does not automatically mean officers acted unreasonably)
People v. Krueger, 175 Ill. 2d 60 (Illinois rejected application of federal Krull good-faith exception under state constitution)
People v. Carrera, 203 Ill. 2d 1 (void ab initio doctrine bars retroactive application of a later-declared-unconstitutional statute; good-faith exception not applied)
People v. Aguilar, 2013 IL 112116 (Illinois Supreme Court held portion of AUUW statute banning public handgun possession facially unconstitutional)