District of Columbia v. Wesby, 138 S. Ct. 577

Police responded to a late-night complaint about loud music and illegal activity at a house neighbors said had been vacant for months.
Officers entered after someone opened the door and found ~21 people, a near‑empty house (few chairs, one mattress), evidence of drug/alcohol use, a makeshift strip‑club, sexual activity, used condoms, and generally filthy conditions.
Many partygoers scattered or hid when officers arrived; interviews produced vague, inconsistent stories (claimed a "Peaches" invited them; no one could identify a bachelor or provide details).
Officers spoke to "Peaches" by phone; she was evasive, initially claimed she had permission but later admitted she did not; the owner confirmed no permission had been given.
Officers arrested the attendees for unlawful entry; charges were later dropped. Plaintiffs sued under 42 U.S.C. § 1983 and D.C. law for false arrest. District Court granted summary judgment to plaintiffs on probable cause and denied qualified immunity to two officers; D.C. Circuit affirmed in part.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Probable cause for arrest for unlawful entry — whether officers had reason to believe attendees "knew or should have known" entry was against owner's will	Partygoers: Peaches invited them; officers had no evidence they knew entry was unauthorized, so no probable cause	Officers/D.C.: Totality of circumstances (vacant‑looking house, drug/alcohol, strip‑club activity, scattering/hiding, evasive statements) supported reasonable inference attendees knew entry was unauthorized	Court: Under totality of circumstances, a reasonable officer could infer attendees knew entry was unauthorized; reversed D.C. Circuit and held there was probable cause
Qualified immunity — whether unlawfulness of arrests was "clearly established"	Partygoers: D.C. law (bona fide belief defense) clearly established that an uncontradicted invitation negates intent required for unlawful entry, so officers should not be immune	Officers/D.C.: No controlling precedent placing this outcome "beyond debate"; reasonable officers could have (mistakenly) concluded probable cause existed	Court: Officers entitled to qualified immunity — no clearly established law defeating arrests under these circumstances and no on‑point precedent

Maryland v. Pringle, 540 U.S. 366 (totality of circumstances test for probable cause)
Illinois v. Gates, 462 U.S. 213 (probable cause is totality‑of‑circumstances, not a checklist)
Illinois v. Wardlow, 528 U.S. 119 (flight on police approach is suspicious and may inform probable cause)
Devenpeck v. Alford, 543 U.S. 146 (officer need only have probable cause for any offense; untruthful/evasive answers can support probable cause)
United States v. Arvizu, 534 U.S. 266 (must consider whole picture; do not dismiss facts because they admit innocent explanations)
Anderson v. Creighton, 483 U.S. 635 (qualified immunity protects officers who reasonably — but mistakenly — conclude probable cause exists)
Brosseau v. Haugen, 543 U.S. 194 (in warrantless‑arrest context, a body of relevant case law usually required to clearly establish constitutional violation)
Atwater v. Lago Vista, 532 U.S. 318 (warrantless arrest is reasonable if officer has probable cause)
Payton v. New York, 445 U.S. 573 (Fourth Amendment protects against unreasonable seizures of the person)
Malley v. Briggs, 475 U.S. 335 (qualified immunity aims to protect all but plainly incompetent or knowing violators)
Hunter v. Bryant, 502 U.S. 224 (clearly established law must be settled at the time)
Saucier v. Katz, 533 U.S. 194 (rule must clearly prohibit officer’s conduct in the particular circumstances)