Study: Drug Dogs Most Likely To Err In Traffic Stop Scenarios

  • by Paul Armentano, NORML Deputy Director March 24, 2014

    Dogs trained to detect the presence of illegal drugs are most likely to provide false alerts in situations involving the search of a motor vehicle, according to the findings of a study published online in the journal Forensic Science International.

    A team of researchers from the United States and Poland assessed the ability of trained drug sniffing dogs to accurately detect the presence controlled substances – including marijuana, hashish, amphetamines, cocaine and heroin – in various environments.

    Dogs were most likely to correctly identify the presence of contraband, particularly marijuana, during searches of individual rooms. If the dog had previous exposure to the room prior to the search, it was least likely to provide a false alert (83 percent correct identifications versus 10 percent false alerts).

    Dogs were far less reliable in scenarios designed to mimic real-world traffic stops. In situations where dogs accessed the perimeter of a motor vehicle, the animals accurately alerted to the presence contraband only 64 percent of the time. Fifteen percent of the time dogs failed to recognize the presence of illicit drugs. Twenty-two percent of the time the dogs indicated that illegal drugs were present when they were not.

    Drug dogs’ failure rates were even more pronounced in situations where the animals had access to the inside of a vehicle. In this scenario, dogs correctly responded to the presence of contraband only 58 percent of time. They provided false alerts 36 percent of time.

    Previous studies have similarly documented drug dogs’ tendency to provide false alerts. In 2011, researchers at the University of California at Davis reported that the performance of drug-sniffing dogs is significantly influenced by whether or not their handlers believe illicit substances are present. That same year, a review of Australian government statistics, published in the Sydney Morning Herald, found that some 80 percent of drug dog alerts in New South Wales yielded no illicit substances.

    In 2005, the United States Supreme Court ruled in Illinois v Caballes that an alert from a police dog during a traffic stop provides a constitutional basis for law enforcement to search the interior of the vehicle.

    29 Responses to “Study: Drug Dogs Most Likely To Err In Traffic Stop Scenarios”

    1. Dustin says:


      You are correct about the law enforcement officer possible giving hand signs for the dog to alert. This is only my opinion, but I can testify as an expert on the stand, you can challenge this in court.

      You need to ask if the Officer was involved in the dogs training or if the dog was purchased from a private company. If the Officer was involved in the dogs traning from the beging. If they have been, it isery easly possible they train the dog to alert on objects buy the handler just reaching for the dogs reward, like ball or rolled up towel for example.

      I will give the benifit of the doubt for some officer’s who don’t know they are doing it but I have to believe some officers do it intentionally especially if they are looking for “Probable Cause” especially if they have been called out for the drug team, DEA ect…..

      Some DA’s are getting smarter now asking for more evidence than just an alert from a drug dog now. They want at least two differant things (reasons) for them to even conduct a search.



    2. Julian says:

      @Julian says (Dustin),
      Touch your nose!
      Julian says
      Vape a bowl!
      …go to the fridge…
      …you’re oooooout…

      Dustin, there are some serious scandals rising up from all three of those agencies you mentioned. Many of us have heard the tales of how the CIA ran planes with cocaine from Colombia since the 80s to fund private drug wars and sell weapons for profit. But now they’re facing a report that is going to be released any week now about how their torture techniques were useless since 911. And they were busted by their former defender, Senator Feinstein, for cyber attacking her Senate office files.
      As if the DOJ didnt have enough trouble, people are learning more every day about the DEAs SOD program, and the unjust hypocrisy of the Controlled Substances Act that created the agency in the first place. Recent movements from the State Department to deploy state troopers, or DPS to foreign nations under drug war contracts suggest the Obama administration may already be downsizing the role the Department of Justice plays in these, unjust, expensive, ongoing drug wars by switching Departments… Wait, like switching judges! Got us with the ol’ swap and scramble again, didntcha Obama!
      But the one that gets me the most is the ATF. We dont hear much about the Fast and Furious Scandal a few years back when the ATF was busted selling U.S. weapons to both sides of the Mexican drug war… That got a DEA agent killed and thousands of innocent immigrants and innocent Mexican people too.
      But when even less people know is that of a little known law passed in the 80s (backed by the NRA) that allows the ATF to conceal serial tracking numbers of weapons sales in the United States. If you think about what that means, a reporter can’t find out how many bushmaster rifles were sold in the wake of the Newtown massacre… Because the ATF doesnt have to tell them. (Moyers & Company) So they can sell weapons to the Mexican military and warring cartels to contrive a drug war and hide the deal by calling it a “tracer program.” …So they can sell more weapons. This bad law is an integrel component of the military-drug-prison-industrial-complex. (Say THAT hyphenation twice fast).
      Of course, we’re just “conspiracy theorists” if we believe the CIA isnt censoring our “free press” right? But it doesnt help that our free press follow decoy stories with a “look, squirrel!” call. Like when everyone lost focus on Obama’s response to international scrutiny to the failed drug wars at the 2011 Summit of the Americas because the DEA lead the Secret Service to a bunch of prostitutes in Cartagena. So much for the President’s response during an election year. It was a juicy sexpionage story!
      But people are getting their media sources from non for profits, internet sources, and from a rolling event of developing violence that keeps unfolding with “unclear motives…”

      We all wonder if the outcome of gun violence in America would be different if marijuana was legal.

      Im sitting here watching the Fort Hood story, and a reporter says the shooter was on prescribed medication for PTSD. Let me guess; the medication wasn’t reducing symptoms of violence and the prescription wasn’t medical marijuana.

    3. Julian says:

      Im sorry to hear that you live in New Mexico. Absolutely beautiful, but it’s absolute anarchy over there. It’s so corrupt in New Mexico you may as well call up the Governor to deputize you, put a star on your coat and call yerself Wyatt Earp, cuz there aint no real justice that I could find. From the trailer parks in the desert to the paid security in Angel Fire, there are places no cop in their right mind would go even if they were well trained. Seems to me like legalizing marijuana is one of the few ways we’ll ever reduce the violence in New Mexico. Too bad. Sure is a beautiful state.
      Just keep in mind that “nigger” don’t have the same meaning in every part of the Country. Don’t go to a march in Washington D.C. and get caught saying that out loud. The reaction you might get could take on a whole new meaning for you in life.
      Oh, and about the old “good judge, bad judge” argument; there are laws that prevent judges from speaking about the pending cases of other judges. But there are no laws, at least in our states of New Mexico and Texas, that prevent a judge from soliciting lawyers with pending cases for campaign contributions. In other words, if a crooked government agent, officer, prosecutor or judge want to close a drug case for kickback$ and a good judge isn’t cooperating, they simply SWITCH JUDGES.
      Just save yourself the migrane and donate to Norml.

    4. Dave Evans says:

      Julian, I just watched the nigger police of Albuquerque murder someone for no reason. What is happening to this country??? Let me guess, those pigs did everything by the book and they aren’t magically guilt of murder, right?

    5. Dave Evans says:

      Julian, I get what you’re saying, but I disagree that about words “becoming bad” for usage because some random sociopaths used those words in the past. It is freaking ignorant to effectively give these losers pieces of our language. Jessie Jackson and his rainbow coalition are just wrong about banning the word.

      I actually know people that are police. Some were stoners before they became officers. Slowly but surely they all turned into assholes and lost all their friends. They would complain about how “No one respects the police anymore” and I’d explain that it isn’t the police’s job to be assholes, pulling someone over for speeding and give them four or five tickets is abuse, that the police didn’t used to act this way… Now they feed off of people stepping over lines drawn in sand and don’t get in trouble if they shoot you for no reason. The fastest way to only have dicks for friends or no friends? Become a cop. I respect the job police do, but police in this country literally 50% garbage officers; their training is wack and they don’t police well and their “blue wall” keeps them from not being pigs.

    6. Dustin says:

      Just remember the officer is not going to say ” The dog alerted on marijuana.” The officer going to say ” The dog is trained to alert on the presence of the odor of narcotics.” After that the DA might ask the officer what narcotic “odors” has the dog been trained in.

      Now there is also the case of “residual odor” they might use. This is total bumpkin as far as I’m concerned (my opinion of course).

      This is the situation were the dog alerts on an object that possible “was in contact” with the drugs. An example would be money. But, what they don’t tell you is about 90% of all money is contaminated. If the dog alerts on your money. Ask the officer to pull a one dollar bill or twenty dollar bill out of his/her pocket and see if the dog alerts on that. I bet they they won’t because they know most money is contaminated. Even the money little old grandma an grandpa have.

      In most case the officer will seize your money because the dog alerted on it. Hopefully, with this knowledge you could possibly save yourself from getting your money seized by reminding the officer of these facts.

      If they do sieze your money just make sure you reminded them of this fact. Note the time and to write it down as soon as you can so that you have it documented.


    7. Dustin says:

      Huh, my last comment says “Julian says”. I apologize for that Julian. I guess my brain was a little gassy (brain fart). It is suppose to say ” Dustin says”

      Sorry for any confusion,


    8. @Julian says:

      Unfortunately, I cannot say about Texas. I’ve only lived here a short time. I can tell you more about another state that is unrelated to Texas and not a boarder state.

      I have never been around the DEA. I do strongly believe the agency should not eggsist along with the ATF and CIA. It is completely obvious of the corruption in system, or should I say corporate system. But I can’t give you much information other what other say like yourself as an example.

      I didn’t want to say this but I do have, let’s say, experience, in the drug “detection” dog area. When I say a lot I mean a lot. I’m afraid if I say more, it will start a verbal bashing compain and I will not be taken seriously. It’s not like I haven’t been verbally bashed before but, I just rather not this time.

      Thank for the information Julian,


    9. Dave Evans says:

      Julian, no, good judges are not being “silenced”. They must be too well trained to open their mouths because no one can actually stop a judge.

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