United States v. Perez-Diaz, 848 F.3d 33

FBI undercover download traced to Pérez's former family home; agents executed a warrant there and learned Pérez had moved and taken computers with him.
Agents went to Pérez's apartment, entered the building via a back gate, knocked, and conducted a knock-and-talk; Pérez spoke through the door then invited agents inside.
During the conversation Pérez admitted searching for pornography, produced an old hard drive, but refused to let agents access a laptop; agents stopped the interview and secured the premises while an agent obtained a warrant.
After obtaining a warrant (~3 hours later) agents searched the apartment and seized electronics; forensic analysis revealed extensive child pornography.
Pérez contested the entry, arguing agents forced the locked back gate, entered and seized property without consent or a warrant; district court credited agents’ testimony, denied suppression after two hearings; Pérez preserved appeal in guilty plea.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether agents trespassed on curtilage	Pérez: back-gate entry and passage to door invaded curtilage	Govt: agents merely passed through to knock; no force used	No Fourth Amendment violation — passage to knock permissible under implicit license (Jardines)
Whether entry into apartment was consensual	Pérez: agents forced entry, coerced him into letting them in	Govt: Pérez voluntarily invited agents inside and answered questions; withdrew consent before warrant	Entry was consensual; consent voluntarily given and then withdrawn appropriately; agents ceased and sought warrant
Whether temporary seizure/securement of apartment pending warrant was lawful	Pérez: agents unlawfully seized apartment and detained him without warrant	Govt: probable cause existed; risk of evidence destruction; seizure was reasonable and limited	Seizure reasonable under McArthur factors — probable cause, risk of destruction, minimal intrusion, limited (~3 hours) duration
Whether district court clearly erred in credibility/findings	Pérez: objective evidence (photos, locksmith) contradicts agents and shows forced entry	Govt: photos inconclusive; witnesses not persuasive; court properly credited agents	No clear error; appellate court defers to district court credibility determinations

Florida v. Jardines, 569 U.S. 1 (2013) (implicit license to approach home to knock informs curtilage analysis)
Kentucky v. King, 563 U.S. 452 (2011) (knock-and-talk and limits on compelled entry and questioning)
Illinois v. McArthur, 531 U.S. 326 (2001) (four-factor test for temporary seizure to prevent destruction of evidence)
United States v. Vanvliet, 542 F.3d 259 (1st Cir. 2008) (government bears burden to prove consent voluntariness; totality-of-circumstances test)
United States v. Silva, 742 F.3d 1 (1st Cir. 2014) (probable cause standard for searches of particular places)
United States v. Guzmán-Batista, 783 F.3d 930 (1st Cir. 2015) (deference to district court credibility findings on suppression issues)