by Sherry F. Colb
In my column for this week, I discuss a case from Minnesota that may make it to the U.S. Supreme Court. The case raises the question whether a dog sniff of a private resident's door constitutes a "search" for purposes of the Fourth Amendment bar on unreasonable searches and seizures. The Minnesota Supreme Court held that the answer was "no" and that police therefore needed no warrant, probable cause, or other indices of reasonableness for having brought the drug-sniffing dog to detect narcotics in the house from outside of the house.
The answer to the question may turn on how the Court defines a "search." The Katz v. United States definition (really the Harlan concurrence's definition) is the invasion of a reasonable expectation of privacy. The more recent (though also more ancient) definition has to do with the invasion of property, of "persons, houses, papers, and effects," rather than an inquiry about privacy and the expectations that people do and ought to be able to hold. We could answer both questions the same way, to be sure, but one might head in different directions depending on which question one selected as critical. Should people be able to expect privacy from K9 police detecting drugs in their homes? Does the use of K9s interfere with a person's enjoyment of his property rights in his home?
As I discuss in my column, Justice Kagan writes a concurring opinion in an earlier case involving a dog sniffing at a person's home, Florida v. Jardines. She says that the reason a dog sniff of a person's home ought to count as a search is that the dog is very much like a special technology that people can use to find out that something undetectable by human senses is inside a private residence. An earlier case involving a special technology, a thermal detection device, held that police could not use it without obtaining a warrant.
One can identify a number of distinctions between Jardines and Kyllo, the latter of which involved a thermal detection device. For this post, though, I want to focus on one distinction in particular--that between a living, sentient being like a dog, on the one hand, and a mechanical device that detects the presence of light or some chemical, on the other. I discussed the dog/machine distinction in a column I wrote a while back. But my emphasis there was the perspective of the dog/machine. Dogs have wishes and thoughts, while machines (at least for now) do not. In my column, I pointed out that because they have wishes and a theory of mind (which enables them to tell us things that we did not know), dogs can "lie" to us if they see an advantage in doing so. The bomb-sniffing dog who alerts to a car trunk containing nothing but a tennis ball, which the dog grabs in his mouth, provides an example of such deception. Machines, by contrast, are either accurate, inaccurate, or somewhat accurate. They do not try to deceive us to fulfill their own needs.
The fact that dogs have a perspective and a theory of mind means that dogs can be curious about things that we already know but they do not. For example, dogs detect things about a growing fetus/baby in the womb. How do I know? When I was pregnant with my younger daughter, I had two dogs, Scooter and Mandy. One night, I went to the hospital and returned two days later with a little infant in tow. Ordinarily, my dogs were extremely curious about babies. They sniffed at them and tried to kiss them. I like to think that my dogs found babies cute in the way that so many people found my dogs cute. When I returned home, however, my dogs showed no interest whatsoever. They did kiss the baby now and then, but our entry into the house--which I thought would yield significant canine drama--triggered nothing at all from the dogs. They reacted as though they had already met my new daughter, and our coming through the door was nice but nothing special. I concluded that the dogs had thus not only determined that I had been pregnant but somehow knew that the little bundle I held was the very one with whom I had been pregnant. They had detected the baby, maybe by heartbeat sounds (to which I had dutifully/obsessively listened with my two-year-old every day for months). Dogs acquire such knowledge, whether or not a police officer "deploys" them and whether or not a human can "read" the dog's mind.
I mention the difference between dogs and investigative devices to pose the following question, which is the point of this post: Do we feel like someone has invaded our privacy when dogs figure out something about us? Imagine that a police officer holds a thermal detection device in his hand, and the device detects heat patterns in your home (which, if precise enough, could provide a kind of picture of the inside of you home). If you feel that the police have invaded your privacy (which you likely do), it is because police officers will be looking at the quasi-photograph, either immediately or at some later point. You probably do not feel a sense of shame in thinking about the device itself "knowing" what the inside of your home looks like. Only someone can invade your privacy in a recognizable way, in other words. Something (such as a device) cannot. To be more graphic, if a robot walked in on you while you were using the bathroom, you would probably be relieved that it was just a robot (until, that is, you noticed that the robots' arms held automatic weapons).
So what? What am I trying to say? I am suggesting that there is an "I-Thou" aspect to the relationship between A and B when A invades B's privacy. If A is simply a piece of property, a thing, then B will not experience A's "witnessing" of B's personal matters as intrusive. If I am writing something personal on a piece of paper, I have no problem with the fact that there are walls and a ceiling there. If I worry about something, it is that a camera or other recording device will take down what I write and then provide it to others who can read. But really, it is not so much the capacity of others to read as it is their capacity to judge that bothers me. It is their ability to know that what I have written confesses a misdeed or reveals an embarrassing fact about myself. If the only entities that will ever learn of what I wrote are machines, then no one can judge me or what I have written. A machine will not think of my prior robbery conviction, confessed in my writing, whenever it "sees" me.
If I am correct about what I have said, then it follows that dogs do not invade our privacy. I do not mean to suggest that dogs cannot be a necessary link in the exposure of private matters. A dog can tell a police officer that you have illicit drugs in your home or even that you have cancer (which some dogs can sniff out better than existing devices). My own "pet" theory on disease detection by dogs is that the reason dogs sniff each other's butts every day (often several times), even when the dogs know each other well, is to examine each other's health. Within a wolf pack, the selection of a leader would presumably turn in part on the respective health of the various pack members. Like another human who spies on you, then, dogs can take in a piece of information--information that he or she wants to know--and think about it. Dogs thus achieve step 1 of what it takes to make you feel intruded upon.
The dogs do not, however, judge you (at least not to our knowledge). Indeed, the characteristic of dogs that most of us find enchanting is their willingness to adore their people regardless of what the latter do. A dog will never look down upon his human for being too inert, for failing to fit into last year's swimsuit, or for doing or not doing anything in particular. Indeed, dogs are so loyal that most would rather remain with a human who cannot take decent care of them than move to a new person who can. Dogs are like what doctors pretend to be--someone who cares about you but has no subjectively negative reactions to the facts that they turn up about you.
In dog sniff cases, it may therefore seem sensible to speak of the dogs as though they are detection devices. Dogs do not judge us, and they accordingly seem unable to make us feel like our privacy has been invaded. Does it really matter, then, that they are sentient?
I think it matters. First, I should point out that some people do feel that dogs can invade their privacy. I have had people visit my home, where three dogs live. Upon approaching the restroom, my guest might find one of my dogs attempting to join him or her there. The guest sometimes would prevent the dog from entering the restroom and explain that they wanted privacy. Why they wanted "privacy" from a dog is another question, but they did. Therefore, unlike a device, a dog might be able to invade the privacy of some people.
Second and perhaps more importantly, understanding that dogs are sentient beings rather than machines can help explain why dogs make errors. They make errors in detecting things not because every machine has an error rate, but because dogs are better and worse at an activity in the ways that humans are. If a dog is hungry, uncomfortable, nervous, or otherwise "off his game," he will make errors. If he senses that his handler wants him to indicate a finding, he is motivated to do so even if it is wrong. Once we understand such things, we might test whether police have probable cause by considering the dog at the end of the sniffing nose.
Whether dogs can invade our privacy also strikes me as an independently interesting question.
As we begin, hopefully soon, to take seriously the moral implications of animals' sentience, it will become increasingly important to notice the difference between utilizing an inanimate object, on the one hand, and exploiting a living, breathing being, on the other. We can then appreciate that the moral questions surrounding the use of an animal to detect facts about a suspect go well beyond the question of the suspect's interest in privacy.