United States v. Pérez-Díaz, 848 F.3d 33

FBI undercover operation in Nov 2010 downloaded child pornography traced to Pérez’s former family home; agents executed a warrant there Apr 29, 2011 and learned Pérez had moved out and taken computers.
FBI located Pérez’s apartment, knocked (knock-and-talk); Pérez spoke through the door, then invited agents in and answered questions in the kitchen.
Pérez admitted searching for pornography and produced an old hard drive; agents asked to see a laptop, Pérez refused and became evasive; agents then secured the premises while Ortiz obtained a search warrant.
Agents obtained a warrant by ~12:20 p.m., searched, and seized computers that later yielded large quantities of child pornography.
Pérez challenged the entry, alleged forced padlock entry, coercive entry into his apartment, warrantless seizure, and sought suppression; district court held two hearings, credited agents’ testimony, denied suppression; Pérez preserved appeal in plea.

Issue	Pérez's Argument	Government's Argument	Held
Whether agents trespassed on curtilage by passing through back gate	Agents forced padlock/opened gate and traversed curtilage unlawfully	Agents used no force to enter gate and merely approached to knock	No Fourth Amendment violation; passing through to knock lawful
Whether agents’ entry into apartment was consensual	Entry was coerced: forced physical entry, sat and interrogated, not voluntary	Knock-and-talk; Pérez (a police officer) consented by inviting agents in and answering questions; withdrew consent re laptop	Consent to enter and initial questioning found voluntary; no clear error in crediting agents
Whether agents illegally seized apartment pending warrant	Agents unlawfully secured premises and detained Pérez beyond permissible limits	Temporary seizure satisfied McArthur factors: probable cause, risk of destruction, reasonable privacy accommodation, limited ~3-hr duration	Temporary seizure reasonable; no Fourth Amendment violation
Whether district court clearly erred in crediting agents over Pérez	Agent testimony contradicted by padlock photos and locksmith/neighbors	Photographs low quality, locksmith unsure, witnesses not present or unreliable; district court credibility determinations entitled to deference	No clear error; district court credibility findings affirmed

United States v. Stokes, 829 F.3d 47 (1st Cir. 2016) (standard of review for suppression rulings)
United States v. Rabbia, 699 F.3d 85 (1st Cir. 2012) (Fourth Amendment review principles)
United States v. Guzmán-Batista, 783 F.3d 930 (1st Cir. 2015) (deference to district court credibility findings)
Florida v. Jardines, 133 S. Ct. 1409 (2013) (curtilage and implied license to approach home for knock-and-talk)
Kentucky v. King, 563 U.S. 452 (2011) (knock-and-talk and voluntary conversation/consent)
Illinois v. McArthur, 531 U.S. 326 (2001) (test for temporary seizure of premises pending warrant)
United States v. Silva, 742 F.3d 1 (1st Cir. 2014) (probable cause standard: fair probability)
United States v. Vanvliet, 542 F.3d 259 (1st Cir. 2008) (government burden to prove voluntary consent)