Carroll v. Carman, 135 S. Ct. 348

On July 3, 2009, Pennsylvania police received a tip that Michael Zita (who had allegedly stolen a car and two loaded handguns) might be at Andrew and Karen Carman’s home. Officers Carroll and Roberts, unfamiliar with the property, went to investigate.
Officers first drove to the front of the house, could not park, then entered a side-street parking area and parked near the rear of the property.
They observed an open small structure and a sliding glass door leading to a ground-level deck. Carroll looked into the structure, announced his presence, then walked onto the deck and knocked at the sliding door.
A man (Andrew Carman) exited the house, acted belligerently, and appeared to reach for his waist; Carroll grabbed his arm, the man fell; Karen Carman identified herself and consented to a search. No Zita was found and no charges were filed.
The Carmans sued Carroll under 42 U.S.C. §1983 claiming a Fourth Amendment violation for entering curtilage/deck without a warrant; a jury found for Carroll. The Third Circuit reversed as a matter of law, holding the "knock-and-talk" must begin at the front door and denied qualified immunity.
The Supreme Court granted certiorari and reversed the Third Circuit, holding Carroll was entitled to qualified immunity because the law was not clearly established that his conduct violated the Fourth Amendment.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Carroll’s approach to the deck/side sliding door and entry onto curtilage without a warrant violated the Fourth Amendment	The knock-and-talk exception requires officers to begin at the front door; going onto backyard/deck was a warrantless entry	Officers may approach and knock where a private visitor could reasonably go (walkways, porches, driveways); sliding door was a customary entry	Court did not decide the general rule; found material dispute but treated jury verdict as consistent with visitor-access route; focus was on qualified immunity rather than resolving a new Fourth Amendment rule
Whether Carroll is entitled to qualified immunity	Carmans: Third Circuit correctly held law clearly established that officers must use front door before entering curtilage	Carroll: Existing precedent did not clearly establish that approaching a non-front entrance open to visitors is unlawful; reasonable officers could believe conduct lawful	Court reversed Third Circuit — law was not "beyond debate," so Carroll entitled to qualified immunity on this record

Anderson v. Creighton, 483 U.S. 635 (1987) (articulates the "clearly established law" standard for qualified immunity)
Malley v. Briggs, 475 U.S. 335 (1986) (qualified immunity protects all but the plainly incompetent or those who knowingly violate the law)
Ashcroft v. al-Kidd, 563 U.S. _ (2011) (clarifies that existing precedent must place the constitutional question beyond debate to deny qualified immunity)
Estate of Smith v. Marasco, 318 F.3d 497 (3d Cir. 2003) (Third Circuit decision on officers entering curtilage after knocking; remanded for factual findings)
United States v. Titemore, 437 F.3d 251 (2d Cir. 2006) (approach to non-front sliding door that is a principal entrance did not violate Fourth Amendment)
United States v. James, 40 F.3d 850 (7th Cir. 1994) (approach to rear/side door accessible to public did not implicate Fourth Amendment)
United States v. Garcia, 997 F.2d 1273 (9th Cir. 1993) (if front and back are readily accessible, officers may approach back door reasonably believing it is a principal entrance)