United States v. Terance Morice Highbull, 894 F.3d 988

Police responded to a domestic-disturbance call; Michelle Janis told Officer Mattson that Terance Highbull had photos of her 13-year-old daughter on his phone and that Highbull’s running Ford Taurus was registered to him at her address.
Janis entered Highbull’s running car while officers were nearby, located Highbull’s cell phone, and handed it to Officer Mattson, saying the phone contained nude photos of her daughter.
Officer Mattson did not direct Janis to search the car, did not open the car himself, and conceded he knew of and acquiesced in her retrieval of the phone.
Forensic analysis of the phone (pursuant to a warrant) uncovered child-pornography images; Highbull was charged under 18 U.S.C. § 2251(a).
Highbull moved to suppress the phone evidence, arguing Janis acted as a government agent so the Fourth Amendment should apply; the magistrate and district court found Janis was not a government agent and denied suppression.
Highbull pleaded guilty while reserving the right to appeal the suppression ruling; the Eighth Circuit affirmed, holding Janis’s conduct was private, not state action.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the private search by Janis implicated the Fourth Amendment because she acted as a government agent	Janis intended to assist police and retrieve evidence to secure an arrest, so her search should be treated as government action	Janis acted voluntarily with personal motives (protecting her daughter) and was not asked or directed to search; police merely knew and acquiesced	Court held Janis was a private actor: government knowledge/acquiescence existed but no government request and Janis was not primarily motivated to aid police, so no Fourth Amendment violation

Skinner v. Ry. Labor Execs.’ Ass’n, 489 U.S. 602 (private-party searches implicate Fourth Amendment only when the private party is an instrument or agent of the government)
Coolidge v. New Hampshire, 403 U.S. 443 (Fourth Amendment protects against searches by government or those acting at its direction)
Burdeau v. McDowell, 256 U.S. 465 (private-party searches generally not subject to Fourth Amendment)
Wong Sun v. United States, 371 U.S. 471 (suppression principles governing unlawfully obtained evidence)
United States v. Wiest, 596 F.3d 906 (8th Cir.) (three-factor test for private-party government agency: knowledge/acquiescence, private actor’s intent, government request)
United States v. Smith, 383 F.3d 700 (8th Cir.) (dual motives—part private, part to assist police—do not automatically create agency)