Any time an appellate court hands down a ruling involving drug-sniffing dogs, I pay attention. Not for personal reasons, mind you—strictly a political junkie here—but because I've long been interested in the unique (or sui generis, as the courts prefer) legal status of the dog-sniff. Because they're non-intrusive and detect only the presence or absence of contraband, something in which the law recognizes no legitimate privacy interest, they've been ruled not to constiute a Fourth Amendment "search" in most contexts. Because dogs are cumbersome tech, the impact of that rule is limited, but as precise, portable, and cheap sensory tech becomes ubiquitous, those dog-sniff precedents could become enormously significant. With apologies to Erica Jong, I call these "zipless searches."
Via FourthAmendment.com, I see the Second Circuit has handed down a decision fleshing out the scope of the dog-sniff exception. The particular ruling hinges on a less-interesting question about whether the "curtilage" of a home (the protected area surrounding a house, such as a fenced in yard) extends to the brush behind the house where one too-clever-for-his-own-good fellow appears to have been hiding his stash. What's more important, though, is that notwithstanding the Supreme Court's 2005 holding in Illinois v. Caballes reaffirming the special status of the sniff, the Second Circuit held to the logic of its own 1985 ruling affording special protection to the interior of the home.
That didn't do much good for the appellant in this case, since the court considered the brush behind the house too "public" to be due the heightened level of protection due that homes are afforded under the Fourth Amendment. But, invoking the Supreme Court's ruling in Kyllo v. U.S. (2001), which involved the use of infrared scanners to detect a marijuana-growing operation, the Court made clear that it still believed a dog sniff (and presumably the technological equivalent thereof) would constitute a search if it were used to detect the presence of drugs within the interior of the home.
In a way, that's surprising, because the logic of Caballes potentally has rather broader implications. The special features of dog-sniff type searches—targetedness and the absence of physical intrusion—hold true wherever the contraband happens to be located. On the other hand, the broad language of Kyllo can be read to suggest that the expectation of privacy within the home is so strong as to establish a kind of per se rule: Everything in the home, even contraband, is presumed to be private.
This actually creates an interesting quandary, though. It turns out that the drug stash in this case was located beyond the curtilage of the home. But there was no way to know that in advance. Given a sufficiently sensitive nose or scanner, the dope could have been in the garage, or perhaps even the interior of the home. Now, you might think, so what? If a dog or a device picks up traces of drugs, and following that lead suggests that the stuff is inside a protective space, the cops just go get a warrant to go in and search the premises.
The problem is this: As I understand the court's reasoning, whether or not a Fourth Amendment "search" has taken place depends on the location of the drugs—on whether the sniff or scan has revealed information about the interior of a protected domain—not on the location where the search is conducted. (That's why in Kyllo, the infrared scan of the home was a "search" even though the cops stayed parked across the street.) If the stash had turned out to be in the garage, then the sniff would have been an improper search, even though the cop would not have had any way of knowing this in advance. And (intuitively—please bear in mind that I'm a layman here) that would seem to entail that the results of that search are "fruit of the poisonous tree," which would preclude using that information as the basis for a warrant to search the home.
Here, too, none of this would have mattered in the particular case under consideration, since the cops had ample other grounds for a warrant, which was already on the way when the pooch discovered the stash. But questions like this seem bound to arise if, ten years from now, every beat cop is equipped with an inexpensive handheld device that acts as a geiger-counter for drugs. (Not a huge stretch given that working prototypes of such tech have been in development for at least five years.) The rule articulated by the Second Circuit, under which police can't know in advance whether a particular scanning action constitutes a "search," seems destined to become unworkable.