“But introducing a trained police dog to explore the area around the home in hopes of discovering incriminating evidence is something else. There is no customary invitation to do that. An invitation to engage in canine forensic investigation assuredly does not inhere in the very act of hanging a knocker. To find a visitor knocking on the door is routine (even if sometimes unwelcome); to spot that same visitor exploring the front path with a metal detector, or marching his bloodhound into the garden before saying hello and asking permission, would inspire most of us to—well, call the police. The scope of a license—express or implied—is limited not only to a particular area but also to a specific purpose. Consent at a traffic stop to an officer’s checking out an anonymous tip that there is a body in the trunk does not permit the officer to rummage through the trunk for narcotics. Here, the background social norms that invite a visitor to the front door do not invite him there to conduct a search.”
In other words, the officers did have a legal right to enter the curtilage of the home to conduct a “Knock and Talk”, but when they brought the canine along, it was no longer legal. The officers turned the typical “Knock and Talk” into a search, which as stated above is prohibited by Fourth Amendment protections.
Now for my opinion, which since I’m not one of the Justice’s, it doesn’t mean much. Every being has a different sense of smell, hearing and vision. I have been in situation where I have smelled marijuana and my partner (human) didn’t. Does that put me in the same boat as a canine? Just because a canine has more olfactory receptors than a human, doesn’t make them special. You could walk through a cloud of marijuana smoke with the common house dog and I’m sure it is going to start sniffing around, not that it knows what it is. Dogs sniff. Narcotics dogs are doing what they are trained to do. They pick up on one of the trained odors, bracket until they zero in on the strongest point (source) and generally sit to indicate they found it. It is all training. During training we are not enhancing their born abilities; we are just getting them to focus on specific odors. Until marijuana was put in front of me for the first time and told what it was, I didn’t know what that odor was. But with training, now I do, so how is that much different with a trained narcotics canine? I don’t see much difference between me or a canine smelling marijuana other than they are able to pick up on much smaller traces of marijuana and other narcotics.
I agree and disagree with S.C.O.T.U.S. on this matter. Although we can walk down a public sidewalk in a neighborhood with a narcotics canine, we shouldn’t be leading that canine down every driveway and walkway in hopes of getting a hit on some narcotics. I do think that if I’m need to go do a “Knock and Talk”, that I should be able to have my canine partner by my side. Whether it is me or the canine smelling a narcotic, it shouldn’t matter. Then again, my opinion doesn’t matter as much as S.C.O.T.U.S.
Read the Florida v. Jardines opinion for more detailed information.