Civil Liberties

The Myth of the Infallible Police Dog


In Caballes v. Illinois, the 2005 Supreme Court decision that upheld the use of drug-sniffing canines during routine traffic stops, dissenting Justice David Souter noted that "the infallible dog…is a creature of legal fiction." Since false "alerts" seem to be fairly common, Souter warned, it's not safe to assume that signals from police dogs reliably indicate the presence of illegal substances, a premise underlying the Court's conclusion that a dog sniff does not count as a "search" for Fourth Amendment purposes. Now the myth of the infallible police dog is receiving attention in a new, even more troubling context: the "dog-scent lineup," in which a dog is expected to match a suspect's smell to olfactory evidence from a crime scene. Such tests, which can be compromised by cross-contamination of samples or by involuntary cues from handlers or detectives, do not merely provide pretexts for otherwise illegal searches; they can put innocent people in jail.

A front-page story in today's New York Times highlights several such cases in Texas. One man spent eight months in jail after a dog-scent lineup falsely implicated him in a triple homicide. Another was locked up for nine months after a police dog allegedly connected him to a series of robberies, even though security camera footage showed someone else. In both cases, the dog handler was Fort Bend County Sheriff's Deputy Keith A. Pikett, who consults widely throughout the state. The Innocence Project of Texas estimates that 15 to 20 people are in prison based mainly on Pikett's testimony, even though the FBI cautions that dog-sniff tests "should not be used as primary evidence." Rex Easley, a lawyer representing a man who was falsely accused of murdering his neighbor based on one of Pikett's lineups, calls the deputy a "charlatan" who "devised an unreliable dog trick to justify local police agencies' suspicions." The head of a British police dog unit who reviewed footage of the lineup that implicated Easley's client told the Times, "If it was not for the fact that this is a serious matter, I could have been watching a comedy." Pikett declined to be interviewed for the Times story.

I discussed Caballes in a 2005 column. Julian Sanchez considered the implications of its reasoning in a 2007 Reason article. This year Radley Balko noted the incredible forensic feats performed by police dogs under the supervision of the late Florida canine handler John Preston.

NEXT: Reason Writers Around Town: Shikha Dalmia on Ayn Rand at Forbes

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  1. What the hell is wrong with these people. You use Rover to sniff people out. But Rover has never been evidence for anything beyond probable cause. My God the idea of Rover sniffing someone out of a lineup and that being considered evidence as opposed to probable cause to go find real evidence is like some kind of a sick joke. It is a real life Far Side cartoon.

  2. I find it impossible to believe that police dogs are not routinely used to search people that you otherwise wouldn't have PC for, to justify suspicions, and so on and so on. We have seen abuse of authority and power in every other aspect of the police culture; why wouldn't it be just as bad with police dog use?

    1. Of course they are. There is lots of case law that says a dog sniffing your car or your person is a minimal intrusion on your privacy and doesn't require probable cause.

      And I don't know that that is wrong. Rover walking by you and sniffing you is not anywhere as humiliating or intrusive as a cop actually searching you. But this goes beyond that. It is one thing if Rover sniffs you as a way to get probable cause to search you for evidence. It is quite another thing to introduce Rover's sniffing as evidence of your guilt.

  3. Does the dog do arithmetic by "counting" with its foot?

    1. No, that's my horse, silly.

      My dog just barks his numbers.

    2. Beat me to it.

  4. I guarantee that every handler has a secret or semi-secret command that causes his dog to bark and sit.

    "Oh, we don't have enough evidence for a warrant."

    "Me and Rover will be there in five minutes."

    Problem solved.

    Goodbye 4th Amendment and thank you America!

    1. In the Never Get Busted DVDs they actually demonstrate how that's done.

    2. they don't even need that, they could give out completely unconsious signals and it would happen, which is why it's ridiculous to use a dog for anything outside of probable cause, and even that can be abused by an unscrupulous officer.

      The counting horse doesn't need to be a scam, the person just has to feel anticipation waiting for the horse to count, then relief when it reaches the right number. The horse sees your shoulders sag, or eyebrows, and realizes it's time to stop.

      They're like little cold readers. They know what their handler wants. Though I can't seem to get Pluto to understand in the winter we wake up an hour later, or how to get me a beer.

  5. Once I was smoking a bowl while driving, fairly standard practice because I couldn't smoke in the dorms. I was driving slowly because of the thin layer of snow on the road. I slipped off the road and gently went into the forest.

    Literally two minutes later a police van shows up. It was a K-9 unit.

    "Hey, Maddy needs to piss so I'm just gonna let her out."

    She ran right up to me. Cleverly, I just acted like a dog person and petted her extensively. Said "Good girl!" a lot.

    Dog went to the other side of the road, pissed and went back into the van.

    That was pretty fucking scary.

    1. OT: i was in the airport traveling domestic on my way to florida to get married and got on the special needs security line as it was the shortest. i had an ounce secreted on my person (in the pocket under the fly of my boxer breifs). Little did I know that the special needs line also had the scanner that sees through your clothes. I nearly shit a brick. Fortunately one of the TSA assholes told me i was in the wrong line and made me get into one of the longer normal lines.

      1. Do you think it is better to do as you did or to throw it in one of your checked bags?

        1. as long as you don't get scanned, keeping it on your person is better. you never know when they're going to go through your bags 'randomly' while at the airport.

    2. Not all K-9 units are for drugs. My cousin is K-9 - his dog is trained to find ditched firearms. You might have gotten lucky and it was a bomb sniffing dog or the like.

      1. I was in Bloomington, IN.

        If they have a fucking bomb-sniffing dog, that'd be an even more egregious use of public funds than normal.

        1. I also had a couple of shots before I left. (I was retarded.)

          After I got out of the car I just started chainsmoking, something which I just don't and never have done.

          I talked to the cop and asked "Hey, been drinkin'?"

          "Nah. Just smokin'" as I held up my smoke.

          Never do anything illegal drug wise in your car without cigarettes handy. They cause of, and solution to, all of life's problems.

        2. Just an idea. In any case, nice save.

        3. Our quaint little shithole with 13,000 people has 2 k-9s.

  6. holy crap that's nuts, a dog lineup? Any dog expert knows dogs are experts at reading your body language and know what you want them to do, there's no way a dog would not be influenced by the handler no mattter how objective the handler tried to be.

    Check out "How to speak dog" by Stanley Coren, he goes into all the cons and carnival exhibits like the dog that could speak a dozen languages, it was all body language even when the handler didn't know he was giving signals.

    how could anyone think to do that at all?

    I almost moved to Texas. I love it and love the people, but all these bad cop / prosecutor stories make me glad I never did. OTOH I live in Chicago so...we make the news just as much.

  7. Doctor Hayne is so pissed for not thinking of this himself.

  8. Our state patrol recently acquired three new dogs. I couldn't believe the police spokesman actually admitted the dogs were going to be used to catch drug runners transporting drugs through the state. What does that have to do with public safety? No fucking wonder our brand new parish prison is already full.

  9. Look up "Clever Hans" on Wikipedia.

    1. Jeff, look upthread about 10 comments.

  10. "I'm just a dog. I only know words like ball... and good... and [prison] rape."

    1. Carl: I don't know if I can sleep anymore. You ever been raped by a dog?

      Meatwad: [pause] Nuh uh.

      Carl: See, I think that's what hell is like. You know, constantly raped by dogs.

      1. Those dogs can smell anything! That's why you got to kick 'em in the throat!

  11. Criminal lawyer to client: "Take a bath in after shave before you show up for today's line up."

  12. How does a defendant cross-examine a dog that has testified against them?

    BTW, the fucked up server says this is not a valid URL. It work in my IE browser: Tophat.jpg

    Who's the cocksucking, mouth-breathing idiot at Reason who bought this shitty, shitty speech-quashing software?

    1. Apparently, the squirrels don't like the " " that goes between "Voodoo" and "Tophat" in the original link.

      1. " "
        that would be the "percent sign followed by the number twenty".

        This is some fucked up crap that salesman sold you guys.

        1. So you don't like the software then?

          1. That's an understatement.

            It tells me it thinks I am Spam
            (for posting the single word "Thanks". Of course Anonimity-bot can post with impunity)

            It tells me my URL is invalid
            (because it omits characters it doesn't like)

            It tells me my post doesn't appear to be in English when in fact it is
            (who'd you buy this from, Wacko Dobbs Software Inc.?)

            It only lets me hit "Reply" for a while
            (the only remedy appears to be closing the browser and starting again)

            It's Garbage

            1. I'm a crappy developer and I even know how to URLEncode the you said, "Crap!"

  13. Only the guilty need fear a search, citizen.

  14. I blame you rabid animal lovers out there, who think of Fido as a family member, capable of extraordinary feats beyond human comprehension. Or who believe that Mr. Whiskers at the nursing home actually communes with a higher power to determine which granny is closest to running out the clock and in need of purring guide to the afterlife. You should be barred from jury duty.

    1. Hey, Fido is a family member. And he is a lot better than most other family members. But he is still a dog.

      And yes animals do know when you are sick. You smell different when you are. And since dogs and cats have much better noses than we do, they can pick that up. They are training dogs to sniff out people with certain kinds of cancer.

      1. and they'll be working for the EvilInsuranceCompanies during pre-coverage physicals.

      2. They are training dogs to sniff out people with certain kinds of cancer.

        No, John, they're teaching them to sniff out people with cancer...who are smoking MJ.

          1. Science, you've broken my heart once too many times.

      3. and they'll be working for the EvilInsuranceCompanies during pre-coverage physicals.

      4. and they'll be working for the EvilInsuranceCompanies during pre-coverage physicals.

      5. and they'll be working for the EvilInsuranceCompanies during pre-coverage physicals.

      6. and they'll be working for the EvilInsuranceCompanies during pre-coverage physicals.

      7. and they'll be working for the EvilInsuranceCompanies during pre-coverage physicals.

      8. and they'll be working for the EvilInsuranceCompanies during pre-coverage physicals.

      9. and they'll be working for the EvilInsuranceCompanies during pre-coverage physicals.

      10. Hey, it's a living.

  15. I reserve the right to confront my accuser with a rolled-up newspaper.

  16. well. ummmm. alrighty then. ?

  17. As always, I advise anyone who gets arrested for anything that carries a prison sentence to post bail, then go on a killing spree. All it takes to go down for murder is a, so screw it. Take some fucks out.

  18. Who's a good police statist?



  19. Theirs lot of love for Hand Banana here.

    1. Smeghead,

  20. I might, just maybe, if I was high enough, say a dog sniff could be used to establish probable cause to search, but as evidence? Geezus. What sort of jackbooted inbred retard would believe a dog is so perfect when a man's freedom is at stake? These lobotomized swine not only believe in God, but they apparently think God is actually their police dog. This nation is screwed, fellas. If it gets any worse, we'll be sailing Chevrolets south to get into the bastion of freedom that is Cuba.

  21. I've had NJSP threaten to bring in a drug sniffing dog on two different occasions.

    The first time, the cop told me that the dog could smell the drugs in my stomach if had swallowed them.

    The other time he went on about using a chew toy to train the dog. If I had drugs stuffed down my pants, and the dog smelled them, he (the dog) would think my balls were a chew toy, and the cop would not be liable if the dog chomped on my balls. I swear to fucking God. I called his bluff, and he got nothing. Both times I did have illegal substances. There are people stupid enough to fall for that shit.

  22. Criminal lawyer to client: "Take a bath in after shave essence of female dog before you show up for today's line up."

  23. I prefer a liberal dusting of powdered Habanero for the cute doggy to snort.

    1. Ah, the old Cool Hand Luke technique.

  24. Much "forensic" science is not science.

    This bullshit should send every D.A. with a HS diploma into paroxysms of laughter before they say, "No really, what's the real evidence?"

    That it doesn't speaks volumes about our criminal "justice" system.

  25. I still don't understand why dog alerts can be used for probable cause. They have an incredibly high false positive rate (maybe that's why). Every time I read in the newspaper about the latest locker search at a high school, it states that the dogs alerted four or five tiimes, but no drugs were found. Has anyone actually done a controlled study to see how reliable the dogs really are?

    1. Actually, a number of studies have been done, and a properly trained dog is very reliable. The problem with the alerts on searches like you're describing is that the dog's nose IS sensitive enough to detect small traces, and scents linger. If someone's had dope in their coat pocket, purse, or backpack, the dog can still pick up the scent even if the dope's been removed.

      But at the same time, no matter how good a dog is, they're not 100%, and that's why courts have traditionally accepted their use as probable cause, but not for actual proof of guilt. In the case of the dog-handler listed, I'm not sure who is more to blame - him for thinking he could do a scent lineup, the prosecutor for actually presenting it as evidence, or the judge that allowed it in court in the first place.

  26. On the prosecutor's campaign-platform, nobody knows you're a dog.

  27. I've seen dogs used very successfully for detecting land mines. Handlers routinely trust their lives to their dogs by walking behind them in live minefields. So I don't have any problem with them fingering some drug-running a-hole.

    1. The difference is the handler looking for bombs, mines, cadavers, survivors, etc, has no interest in whether the dog finds it here or there. So dogs in those situations can be much more accurate since they are not distracted by the body language of their handlers.

      Dogs using to point out people, or even looking for probable cause, can be affected by the body language of their handler. If the handler thinks this person has drugs, his body language will be different, and send a signal to the dog "point this guy out and you'll get a treat" even if the handler isn't conciously trying to do it. The same reason dogs are easy to train makes them not reliable in situations like that.

    2. Yeah, Ed, sure hope you run across a K-9 cop who doesn't like the way you look.

    3. What if it is a drug-running person who is not an a-hole?

  28. Hell we use faulty lie detectors so this isn't really surprising at all anymore.

  29. Brian: Justice. For all? Or for some? Does a dog not feel? If you scratch him, does his leg not shake? Yes, he is man's best friend. But what, what manner of friend is man? I would like to cite, if I may, the case of Plessy v. Ferguson...

    Councilman: Wait a minute. Why are we listening to a dog? Take him away!

    Brian: But, but does not every dog have his day?

  30. How great is this Police Dog's training?:

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