Yes, in most jurisdictions. In Florida v. Harris (2013) 568 U.S. 237, the Supreme Court held that the test to be applied is “whether all the facts surrounding a dog’s alert, viewed through the lens of common sense, would make a reasonably prudent person think that a search would reveal contraband or evidence of a crime. A sniff is up to snuff when it meets that test.” Harris, supra, at 248. The 5th, 8th, 9th, and 10th Circuits indicate that a failure of a final indication was not fatal to the finding of probable cause. In United States v. Villafranco-Elizando (5th Cir. 2018) 897 F. 3rd 635, the court held that the failure of the K9 to come to a final indication did not vitiate the probable cause LE had already developed. See also United States v. Lakoskey (8th Cir. 2006) 462 F.3d 965, 977; ; United States v. Thomas (9th Cir. 2013) 726 F.3d 1086 (lack of final response not fatal to probable cause); United States v. Ramirez (10th Cir. 2003) 342 F.3d 1210, 1212; United States v. Parada (10th Cir. 2009) 577 F.3d 1275. The 6th Circuit has ruled otherwise. See United States v. Davis (6th Cir. 2005) 430 F.3d 345, 356.
Some state jurisdictions indicate no final indication necessary. So long as the handler is able to articulate a specific, reasonable description of the K9’s behavior that signaled the presence of illegal narcotics, the court will not engage itself in the evaluation of whether that K9 should have an alternative means to indicate the presence of the drugs. This is consistent with the approach outlined by the United States Supreme Court, which is whether all the facts surrounding a dog’s alert, viewed through the lens of common sense, would make a reasonably prudent person think that a search would reveal contraband or evidence of a crime. See, for example, State v. Bowden 2018 Tenn. Crim. App. LEXIS 361.
The takeaway here is, then, that the handler must be able to describe with particularity what alert behavior is for that particular K9 and also be able to articulate reasons why the K9 did not come to a final indication/response; for example, environmental factors such as temperature, wet surface, unsteady surface or not enough room as well as factors relating to the investigation itself, such as an overwhelming smell or a very slight smell.
But be warned: a new case with bad facts could be a problem. In Hernandez v. Boles (6th Cir. 2020) U.S. App. LEXIS 2948, a K9 performed a sniff during a traffic stop and alerted to the outside of the vehicle. Then the handler put the K9 inside the car where the K9 was distracted by a bag of fast food. The handler, admittedly embarrassed, then told other LE at the scene that the K9 failed to hit. Handler also shook hands with the occupants of the vehicle and gave them a “thumbs up” as if to say they were in the clear. Supervisor on scene authorized a vehicle search anyway. Court held that the PC from the alert outside the car was dissipated upon the failure of the K9 to alert inside the car. However, since there was no case law directly on point, the court found qualified immunity, which protected LE from civil liability. The criminal case, however, was dismissed because the evidence was suppressed. This was a case of the handler not trusting the first alert and by having the K9 search inside, ended up erasing probable cause from the situation.