CA8: Dog’s instinctive head in the car window wasn’t a trespass

The dog touching the car was instinctive and not handler directed. Therefore, it’s not a trespass. There’s some doubt in the existing rule in this circuit, but not here. United States v. Munoz, 2025 U.S. App. LEXIS 8808 (8th Cir. Apr. 15, 2025):

Chacon argues the dog’s contact with the car was an unlawful trespass, thus an unreasonable search. “The use of a well-trained narcotics-detection dog … during a lawful traffic stop, generally does not implicate legitimate privacy interests.” Caballes, 543 U.S. at 409. “Absent police misconduct, the instinctive actions of a trained canine do not violate the Fourth Amendment.” United States v. Lyons, 486 F.3d 367, 373 (8th Cir. 2007) (holding a drug dog sticking his head through an open window was not a search because the dog did so “on his own” and “was not directed” to do so).

The district court did not clearly err by finding “no convincing evidence to show that the trooper directed the drug dog to make any physical contact with the vehicle.” “[V]ideo footage instead supports the Government’s position that the drug dog acted instinctively when the points of contact were made.” Because the dog acted instinctively, his contact with the car did not violate the Fourth Amendment. True, since Lyons, this court has cast doubt on the dog-instinct versus officer conduct distinction because “the subjective intent of police officers is almost always irrelevant to whether an action violates the Fourth Amendment.” United States v. Pulido-Ayala, 892 F.3d 315, 319 (8th Cir. 2018), citing Ashcroft v. al-Kidd, 563 U.S. 731, 736–37 (2011). Nevertheless, when, as here, “the dog’s alert alone, without” the instinctive act “would have given [officers] probable cause to search … the inevitable discovery doctrine justifies[s] admitting evidence.” Id.