The Long Nose of the Law

Over at the The Volokh Conspiracy Orin Kerr notes that the Supreme Court has reaffirmed that getting sniffed by a police dog does not constitute a search under the Fourth Amendment. I wonder how this will play out if technology replaces the dogs?

There exists an emerging class of chemical detectors for which the best description is artificial noses. Like biological noses, these devices can detect a wide range of compounds wafting in the air. Some designs even use biological receptors embedded in microchips. Within 10 years or so these detectors will reach the level of sensitivity of a dog’s nose and they will fit in a handheld unit. Unlike a dog, these devices will be able to tell us exactly what they detected and in what amounts.

Let’s call these devices eSniffers. Their existence raises all kinds of interesting legal and cultural questions. For example, at what point does the use of an eSniffer become a search under the Fourth Amendment?

Each human being has a unique chemical signature, a scent. We shed our chemical signature as we move around, and its traces remain for hours or days, depending on environmental conditions. Dogs and other animals use this signature to identify individuals. A sufficiently advanced eSniffer could do the same. Moreover, an eSniffer could permanently store an individual’s signature electronically. Our individual scents would become as identifiable and as accessible as our fingerprints.

There are many possible uses for eSniffers in law enforcement. An eSniffer could record which individuals were in a certain area or whether they touched certain objects. Law enforcement could use an eSniffer on a fresh crime scene to record all of the signatures and then go looking for people who match them. Would a cop’s walking down the street with an eSniffer, sniffing each person he passed, constitute a search? What about eSniffers embedded in buildings like metal detectors, checking everybody who passes through?

It doesn’t stop at identifying and tracking individuals. The Law could also use eSniffers to go on fishing expeditions. Traces of drugs, illegal and otherwise, get secreted by the skin and respiration. In principle, an eSniffer could tell if a person used an illegal drug recently, by detecting this secretion in the air. Would an individual’s setting off of an eSniffer in a public area be grounds for suspecting that individual of illegal drug use? At present, being singled out by a drug dog is sufficient in most cases. If every cop carried an eSniffer that might change.

eSniffers might also raise other privacy concerns. Many diseases produce their own scent signatures, and a person with an eSniffer might be able to learn something about your medical condition (and what medicines you take) just by walking by you. Birth control pills alter a woman’s scent and that could be detected as well. Somebody could also tell what you recently ate or drank.

Compared to most animals, humans have a very weak sense of smell. Culturally, people in developed nations have developed an aversion to smell bordering at times on a phobia. We ignore scents whenever possible. Our legal and cultural concepts of privacy don’t currently deal with scent to any significant degree.

eSniffers are going to force us to change that.

13 thoughts on “The Long Nose of the Law”

  1. Will artificial noses be able to detect cancer one day?

    No lie, a Brit woman’s dog kept barking at 1 mole on her leg.

    Wouldn’t bark at any other.

    She was tested, it was cancerous. They thought the chemical composition had changed and emitted an odor. The dog’s nose was sensitive enough to detect it.

  2. We are somewhat halfway there with the swab tests in the workplace. You can swab a computer keyboard or phone at someones workstation and test the sample for drug residue. And it’s being used already.

    I can’t imagine why certain companies wouldn’t use the eSniffer if they are already using the swab tests-Fourth Amendment violation or not.

  3. Swab tests would only violate the Fourth if the results were turned over to the government. If they were simply used to fire someone, then the Forth wouldn’t apply (although in today’s world, this would probably be an ADA violation).

  4. Good point MP. I didn’t think about that. What about if the employer is a Government or Federal agency?

    Would that violate the 4th then?

  5. I think we’re fast approaching an enviroment where if you don’t take extraordinary precautions, such as lining your home with metal to block milimeter waves, your life will be an open book. While if you DO take such precautions, it will be considered evidence sufficient to justify a search warrant.

    It’s an unavoidable consequence of the war on drugs; Since everyone directly involved in a victimless crime intends for it to happen, the police have no way of even learning that a “crime” has taken place except by conducting a search prior to having any evidence. The courts, faced with either giving up on the drug war, or gutting the 4th amendment, are chosing to do the latter. They’re going to finish the job soon enough, if we don’t stop this madness.

  6. Sandy P,

    “Will artificial noses be able to detect cancer one day?”

    In principle although not all cancers. Some cancers express proteins on their surface that healthy cells do not. When those protein shed into the environment they can be detected (smelled). Not all cancers do so however. In fact, most probably don’t. That is the core problem with cancer. The cells are just regular cells of the bodies but growing uncontrollably. They appear to the immune system, medicines and probably sniffers of various sorts as just another cell in the body.

  7. eSniffers are long here. They’ve put breath analyzers for alcohol in police flashlights for many years. I was stopped in such a search when I was younger (they blocked the street and were testing everybody at a “random” roadblock), recognized what was going on, and felt nasty enough about it to screw with them.

    Whenever answering a question, I merely breathed toward the passenger side of the car, turned back toward the officer and held my breath, waiting for the next question. He made it clear that we were going to continue having a conversation until I breathed his way so I eventually had mercy on the growing line behind me and just gave him his little air sample. I hadn’t had a drink in days so, of course, passed. Since this was a stealth test, he wasn’t supposed to admit to me that this is what he was doing but he sort of did by saying “Was that so hard? You can go.”

    If I ever have enough spare money, I’ll get a privacy car that allows me to pass documents, get tickets, etc. without voiding my 4th amendment expectation to a right of privacy. I don’t expect to ever be that rich but it’s a nice fantasy. Eventually, though, somebody is going to build and market such a thing, especially if GM’s bolt on body hydrogen cars get off the ground.

  8. TM – do they make such a “privacy” rig? Can’t I install a retractable steal tray, with a gasketed, air-tight seal on my wife’s ’82 Accord hatchback, just to experiment? (Where’re my power tools?) What’s happened to all those surplus Bank drive-through window-trays, recently obsoleted by ATM’s?

    If you develop this idea, Lutas, you’ll get rich!


  9. The super sniffers may not be, but the random roadblock TM experienced certainly seems to be a violation of the 4th amendment.

    The random roadblock is an example of convienience being given precedence over princple; something that seems, regretably, more common in our culture as time goes by. Makes me want to get on my soapbox and scream “CONVIENIENCE ISN’T EVERYTHING!”

  10. Heh.

    If you drive south from Canada into NY state at Lake Champlain, you will get stopped by the INS (ICE I think, now) semi-permanent roadblock in the Adirondacks and probably asked a question.

    Since they stop everyone, that’s not unreasonable?

  11. Steve – I’ve never seen such a thing advertised anywhere so I’m guessing, no, they don’t make it right now.

    You would need a speaker and microphone (you do have to answer police questions). You would also need, for complete privacy, glass that could be polarized at will so all the cop sees once you stop is pure mirror (no, “in plain sight” excuse). You would also need to evacuate/exchange air so that even the most sensitive of sniffers can’t detect anything. A camera, to ensure police absense before you depolarize the glass to start moving again would make the system complete.

    I hope you see the problem. This is a car guaranteed to throw any policeman into full adrenaline mode. Criminals could misuse such a vehicle so that they could arm themselves and simply shoot an officer at a traffic stop and the poor guy wouldn’t get any warning. Even if you limited yourselves to tray passing documents and speaker/microphone rig, you’re likely to anger way too many cops to make this a vehicle for anybody but the pathologically committed to the cause of privacy.

  12. We’re well along the road to having no expectation of privacy.

    What is the trigger that allows a police officer to punch a license plate number into the database to see if there are any hits?

    Does that trigger still apply when video technology allows immediate, continuous capture of license plate numbers from a passing stream of traffic and immediate, continuous return of BOLOs from that stream?

  13. “What is the trigger that allows a police officer to punch a license plate number into the database to see if there are any hits?”

    Varies by jurisdiction. In many places the cop needs no ‘trigger’, just needs to be bored enough to type your plate number into his laptop.

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