Drug Dogs False Alerts – A Comprehensive Study Of Police Dogs By K-9 Expert Barry Cooper

Click To Hire Barry As Your K-9 Expert Witness 

In 2006, former narcotics officer and current criminal defense expert witness Barry Cooper was the first to blow the whistle on drug dog false alerts. Enjoy this comprehensive study of drug dogs, which includes videos of false and true alerts.

Police K9 false alert

If this cop can get his dog to alert, he can search the auto.

Police K9 true alert

See the difference?

Another true alert

Notice how the handler allows the dog to work and does not manipulate the movements or alert of the K-9?

Exactly how does a police officer make his dog false alert?  How do police dogs detect contraband?  Watch this short video taken from NeverGetBusted Volume 1:  Traffic Stops


True or False? Analyzing a K9 alert


By Barry Cooper

The ability to detect narcotic odors is not specific to just police dogs. All dogs have the ability to smell narcotic odors. A properly trained police K9 is different because it’s trained to communicate the presence of the narcotic odor. This communication is called an “alert.”

Change in Behavior, Then a Scratch

An alert includes noticeable behavior changes triggered by odor interest, followed by a scratch near the odor source. Behavior changes include a sudden “head jerk” in the direction of the odor source, slowing or speeding of a wagging tail, body posture changes and changes in breathing patterns. If the K-9 detects the odor of a narcotic during a search, the dog communicates this to the handler by scratching near the source. Behavior changes without a scratch are not enough to announce an alert, just as scratching without behavior changes is not an alert. Both must be witnessed by the handler in order for contraband to be considered detected.

A police dog goes through these behavioral changes, less the scratch, when curious about other odors such as urine or food, so it’s an error for the handler to call an alert after witnessing behavioral changes only. It’s also an error to call an alert after witnessing only a scratch because the scratch was not preceded by the necessary behavior changes that are always produced when a dog is interested in any odor.

Odor Separation

Unlike humans, a dog has the ability to separate odors mixed together. When presented with a bowl of stew, a human sees all the different ingredients but smells one odor. A K9, though, can smell, distinguish and separate each ingredient contained in the stew.

This explains why masking odors does not work. If a smuggler wrapped a pound of marijuana in sheets of fabric softener followed by a good wrap of foil, and finally placed it in a can of coffee, a dog smells the fabric softener, the foil, the coffee and the marijuana. This “odor separation process” takes time. A K9 cannot properly separate odors if it is rushed through this process.

Drug dogs are taught which odors provide the reward. A dog is rewarded for alerting to a baggie of marijuana. Empty and uncontaminated baggies must then be presented to the dog for an alert. When the K9 alerts, it is discouraged with a command of dissatisfaction and then pulled away from the baggie. This step is repeated until the dog stops alerting on plastic baggies. If this step is skipped, the handler is soon left with a “trashy” dog that alerts on every odor that surrounded drug odors during training.

Let the Dog Work

A K9 must also have room to work through invisible scent cones created by a multitude of odors surrounding the vehicle. K9s must have this space to track the odor’s source. K9 handlers should allow the dog to work freely by grasping the very end of the leash so its movements aren’t restricted or manipulated. In the video, the handler can be seen pulling and pushing the K9’s head instead of allowing the dog to work freely. While teaching K9 narcotic detector classes, I would often tell students who made the same error, “Don’t work the dog, let the dog work.”

After correcting this poor habit many times with students, I learned the reason for this phenomenon is the handler’s fear of the dog not performing by showing disinterest in the vehicle. It’s embarrassing for a cop when his K9 lacks motivation to search a car, and stares at traffic instead of searching for drugs—especially in front of peers.

False Alerts

After a K9 has alerted, the handler encourages the dog by repeating statements such as “get it, get it, get it out of there.” These verbal commands excite the dog into scratching harder and faster, and should never be used on actual street searches until the presence of a drug is confirmed by an officer. If the dog is encouraged to scratch and no drugs are found, the dog is left with the impression that a scratch on a door for legal odors or no reason at all is what the handler desires, causing the K9 to be considered “dirty.” A dog that is dirty means the K9 will scratch on anything to get its reward.

If drugs are located, the K9 should then be brought back to the previous alert area and encouraged to scratch. When the desired scratch is achieved, the handler “pays,” or rewards, the dog by throwing it a toy. The repeated process of verbally encouraging an alert and then rewarding the dog for compliance makes it possible to manipulate any and all police dogs into scratching without a narcotic odor being present! This is referred to as a “false” or “forced” alert.

Barry’s Proven Tip for How to Handle a K9 Search

This tip works. Dozens of citizens have told me of their success with it, and it has worked for me on one occasion.

Anytime a K9 is deployed to search your auto, announce loudly and boldly that you are aware police can make their K9 false-alert and you know what a true alert looks like. This scares the officer, who, after hearing this, will usually walk his dog around the auto and then leave.

Odor Permeation and Your Stash

K9s cannot smell through material. Odors permeate out, creating a scent cone. Almost everything has pores for odors to permeate. Even plastic baggies have microscopic pores. To demonstrate this, place tuna inside a plastic baggie and sniff the outside of the bag. You will notice you cannot smell the fish. Wait a few hours, and you will notice you can smell the permeated fish odor on the outside of the baggie. Lead is a heavy metal and nonporous, but if you hide your stash in a lead box, the K9 handler will become suspicious.

Temperatures affect permeation. Colder temperatures slow permeation, so freezing your stash in a block of ice slows the permeation to almost nothing, but blocks of ice could make a smart K9 handler suspicious. The trick is to hide your stash in materials that have a slow permeation rate, but be careful that you do not contaminate the outside of the packaging. You must then hurry and transport your stash before the pot odors have time to permeate and develop a scent cone on the outside of the packaging.

Foil and glass and oils and cold temperatures are all good because they all slow permeation.

Trying to mask odors does not work. K9s smell like humans see. When presented with a bowl of stew, humans see all the ingredients but smell only one odor: stew. Dogs can separate odors with their supernatural snouts. When a K9 sniffs the same bowl, it smells onion, pepper, tomato, beef, beans, etc. So if you place your herb in a plastic baggie, spray it with perfume, then seal it in plastic tubing and drop it in your auto’s fuel tank, a scent cone will develop on the outside of the fuel tank. The K9 will enter this scent cone and smell the plastic baggie, the gasoline, the perfume, the plastic tubing and the marijuana. This explains how my K9 detected hundreds of pounds of marijuana hidden in gasoline tanks.

Pro Tip

K9s are trained to detect marijuana, cocaine, methamphetamine and heroin. They are not trained to detect mushrooms or LSD.

Good Luck Out There

I hope this information keeps you out of a human cage that is far worse than the cages kops keep their dogs in.


Click To Hire Barry As Your K-9 Expert Witness 

Two fantastic articles covering K-9 False Alerts:



"You may have seen him on the pages of Maxim, or during one of his many appearances on CNN, Fox News and Spike TV. He’s the cop who turned against the drug war. In American pop culture right now, there’s nobody quite like him. As one of the former top drug cops working the Texas highways, he was ferocious, bringing down hundreds of people for possessing even tiny amounts of an illegal substance. In his new life as a humanitarian crusader and activist filmmaker, he’s just as ferocious. Cooper is on a mission to free America’s pot prisoners. In the terminology of war, Barry is an insurgent, lobbing bombs into the fourth estate as his form of penance for all the people he put behind bars on drug offenses.”—True/Slant

Barry recently starred with Woody Harrelson, 50 Cent, Eminem and Susan Sarandon in the anti drug war documentary, “How To Make Money Selling Drugs.” His internet fame via his website NeverGetBusted.com has received global attention by being reported in Rolling Stones, High Times, a feature in Maxim Magazine and a front cover feature in Cannabis Culture and the Texas Observer. His story was picked as a feature on NPR’s, This American Life. He has been a guest on scores of cable news channels discussing the Drug War. He has also appeared as a drug and legal expert in five episodes of SPIKE TV’s reality show, MANSWERS.

  1. danolred 4 years ago

    The police state continues to trample on human rights!

  2. SARm6 4 years ago

    The title should be “False Handler Alerts.” This is about handler errors not the dog errors. This is the lack of training of the handler and “retraining” of the dog. The dog, if trained properly, will alert; passively or aggressively, as trained. It is up to the handler to let the dog work and pay the dog properly. A dog will always take the easiest path to the reward. So if the handler is leading the dog, forcing the dog, then the dog will “alert” for the toy, not for the narcotics or explosives.
    NEVER are you to set the dog up for failure! This confuses the dog. If you have a blank room, and the dog shows no alert, you move on. If the handler believes there is something in the room, then it is a “forced alert” caused by the handler. You have now trained the dog to “alert” for the toy and not the narcotics or explosive. It’s called “Trust Your Dog!”

  3. Yeti 4 years ago

    This has been true for more than twenty years. Cops just simply cannot train dogs generally speaking, and the sliding scale has destroyed police dogs credibility.

    There are so many things wrong with the mindset of police “trainers” who buy dogs already trained, watching the handler more than the area they are searching.

    Then, as an added bonus, they show huge amounts of smelly pot as proof their dogs work. Everyone of us without a cold would find those amounts as well.

  4. duncan 4 years ago

    SARm6 has it right….Yeti, not so much.

  5. itsme 4 years ago

    if your pulled over and the cop wants a k9 to search your car, how much time do they have to get a k9 there?

  6. Portland_Oreogn 4 years ago

    I am so mad right now. Portland, Oregon is so corrupt. We have the worst police here. A stranger pulled a gun on me. I called the police niavely thinking they would want to get the person with the gun. Turns out , not so much. He was military and the police really like military. I did not know he was military or even know the guy. The police are rude to me. Ask me to serch my car about 5 times. I repeatedly say no. So they bring the k-nine unit over. The dog looked like a stupid dog. I am kind of a dog person too. It kind of playfully and not too interestedly rubbed his nose and snout/mought along the side of my car with his head tilted to one side like maybe a human in love might do to a person but not something a dog would do ever. Then the car went about a foot or two away from my car and I swear to god didn’t make any kind of signal or move. I thought they would sit, point, growl or glare or something that would indicate a signal. The dog also had something that looked like a single bundle of dark sage in his mouth and was slobbering the entire time. I don’t know what exactly he had in his mouth. It was dark and looked like a bundle of dark grass. I thought that he would drop the bundle as a sign that he smelled something. He never dropped the bundle. But after the dog stood not exactly still but not exactly moving a foot or two away from my car, one of the four cops I was surrounded by said that the dog had just made a signal that he smelled something in my car. The police open the back door and then the passenger door of my car and the dog kind of gleefully jumped in each side of my car and kind of sniffed or looked around. There was nothing in my car to be found or smelled. It was a rental car that I had had for almost four weeks so there is a possiblity that there could have been drugs in the vehicle four weeks prior, but I am sure the car company had cleaned the car prior to my renting so it seems that would have got rid of the smell. The police did effectively throw and scramble and screw everything up in my car, but they suprisingly missed a few things such as $ 30 dollars, a piece of paper showing that I actually did have a totally unrelated misdmeanor arrest ( not drug or gun related) in another state, and despite all their tearing and searching a bottle of mineral water with a couple of ounces of wine in it which would have been considered an open container of alcohol, I believe. I was worried about the mineral water bottle with wine in it. I had a six pack of mini bottles of water which they opened and dumped a small amount out of each for some reason. Anyway, I am mad. That dog did not signal but obviously I don’t know the dog singaling gestures. I want to sue the police for unlawful search without a probable cause. They confiscated my cell phones and $225 in cash as ” evidence”. They were trying to get a search warrant in order to search my phone. I called to see if they could get one. You can call the court in Washington County, Oregon to see if there is one issued to you. The friendly female clerk who answered told me that there had only been one search awarrant given in the last three weeks. In Oregon the police have to ask a judge or magistrate for warrants via a a sworn affadavit they write. In California I think the DA or an attorney can either ask for a warrant or issue a search warrant. Anyway forcing the police to write the affadavit and ask a judge versus an attorney must really cut down on seach warrants. My fingers are crossed that they still don’t have one, though it is still unclear to me whether that would implicate me. I think I have a good case and of course a better case without a search warrant.

    • Clever_Plover 4 years ago

      Portland, if you are pulled over and threatened with a dog search, Illinois v. Cabbelles is the case law you want to be familiar with. It states if they want to bring a dog in they can take no longer than the amount of time a reasonable and normal traffic stop would have taken. They can NOT hold you there longer and make you wait for a dog. What they can do though is continue to talk with you and chat with you, in a seemingly friendly fashion, while a dog is on the way. This is why it’s important to ask “Am I being detained or am I free to go?” or after you’ve signed your traffic ticket ask “Am I free to go now?” If a cop says you are free to go, LEAVE IMMEDIATELY.
      If a dog is already on site when they pull you over the dog can do a free air sniff around your vehicle, and if it hits they have probably cause to search. You best defense in either of these situations is to calmly state your non-consent to the search, and videotape/audiotape the encounter, which is legal in most states but not all, as long as one party is aware of the recording and/or not interfering with the police’s actions, and then shut up until you speak to a lawyer. Be calm, rational, and polite while asserting your rights. Hope that helps!

  7. Jenny 4 years ago

    To not leave readers hanging I felt the need to give an update on the falsely claimed alerted dog that led to an arrest without cause because someone pulled a gun on me. You would never beleive what happened. You think that all the states are trying to get down on gun use and of course, you would assume, people who attempt to use guns on people in a threatening manner, but not so in Oregon. The guy who pulled a gun on me admitted to attempting to menace, threaten or teach me a lesson and that is the reason he pulled a gun on me. He admitted it in the police report. He did play down what actually did happen somewhat but did admit for the reason he had the gun. Since we were both arrested I was transported to jail and had to sit in the county waiting area of the jail with him for several hours. I screamed at him a few times but the officers made me quiet down. You are supposed to talk to a medical person before or during your booking. I was sitting outsdie the medical office when he was called in to talk to the nurse. I overheard him also openly admitting to having mental problems of some sort. He is an admitting type of guy if nothing else. With all this admitting going on, one would think this would lead to some charges. I called the jail and court house a few times to check on my case and to see what was going on with his. I knew he had to pay bail to realease. And a week and half after my arrest I found out my charges were dropped. I had talked to a few attorney’s prior to this and one had told me he believed that the charges would probably be dropped. He also advised me not to claim myself as a victim in the ” gun guy’s ” case. He felt the police were doing something and they didn’t want me involved with the gun guy’s case. As it turns out the District Attorney decided to drop all charges against the gun guy. That’s right. No charges at all, not even one. So technically it is possible to pull a gun threaten someone and who knows what else and have the DA drop all charges. He or she can decide not to press any charges at all. He or she is the one to decide who is charged and for what even if they have evidence ( the gun) and the defendant, amazingly admits to the crime. I think that the one gun guy was military so that might have been at least in part of the rationale by the DA office, other than being low life worthless ******* ********. I feel much less safe in Oregon now knowing this. The county that this took place in was Hillsoboro. However, the police who arrested me were the Beaverton Police. They have one awards for their outstanding work with the K-nine unit. This maybe so, but the DA of Hillsoboro is working hard to keep gun pulling mentally unstable men with plans of retribution and menacing safely out of prison.

  8. William Maher 3 years ago

    Dogs can smell through WAX too? I’d like to know if you might (please) clarify this particular question please. As far as I understand it -it is not possible for odors to permeate through WAX IE candle wax?

    How about Dutch bred Bouvier Les Flandres dogs they are Dutch police dogs my brother owns one and he is an ass kicking dog real good all the way around.

  9. William Maher 3 years ago

    With a Bouvier Des Flandres it is necessary to select one who’s back legs stand like a cow’s legs stand as they have some that are with slanted back legs and it is a problem. I know this comment is awaiting moderation I just wanted to run the info by you and the reason for the numerous entries in the last comment is due the internet not immediately responding. Thank you.

  10. Donpo5 3 years ago

    Coming out of California towards Reno on 80- Friend got stopped and it seemed like they already knew what they were after. Pulled out the guy driving instintaly and had k9 all over the infected area. The dog did not hit AT ALL!!!!! But the cop thought the driver was nervouse( cold as Alaska standing outside) and then said the dog hit. That dog was calm as hell and never sat down or clawed at anything. Anyways the cops found the Pot very well 6 layer vacuum seal with dryer sheets on vicks rub plus plastic wrap. No WAY EVER the dog smelled that. Needless to say the guy got arrested as they continued searching. As the 2 men was about to head to jail the cops was talking about keeping some of the pot for them self to sell off. WTF?!?!?!?!? Is this right? It is Legal in many states. The guy was a card holder and care giver for cancer patients and what not. How can they treat this like a horrible thing. High bond and everything. Both of the guys had no arrest record one being 68Years old! Come on now. There has to be something that can be done.

  11. Jim 2 years ago

    In reviewing my covert recording of a seemingly clearly unconstitutional set of LEO actions, I noted that the K-9 sniff took about 5 minutes. I remember how at the time the handler kept running the dog around and around my vehicle. I also had the sense the handler was trying to manufacture an alert. Anyway, how long does a legitimate/admissible K-9 vehicle sniff take? Is something like 5 minutes prima facie that the LEOs are up to (their seemingly usual) no good?

  12. Kristy Cartwright 3 months ago

    Ww live in washington stste near spokane in a small town. My friends were pulled over after leaving a gas station on the edge of town and once pulled over for approx. About 15 minutes and a new police k9 was brought out to smell for narrcotics. The officer walked the dog around the vehicle 7 to 9 times with no alert then put back in the car. That officer left came back about 10 to 15 min later asked some questions spoke to other officers and as additional time went by brought a passanger outside the vehicle and olaced them in a olice car leaving stopped vehicles doir open and brought out this police dog a second time going around the car. This time while near open door the dog sat down alerting his handler. At this time the vehicle was impounded and is now being held indefinetly while taking time to get search warrants and search vehicle along with owner of vehicle being told they plan on keeping vehicle for as long as it takes the lab to come back with any samples results. This vehicle was borrowed by a personal family friend of the vehicles owner who had from what the owner new had a liscense and still believes they do however the person loaned the vehicle refussed to drive forcing an unlicensened driver to drive then the person loaned the vehicle gave false name and was arrested. Is any of this legal?

  13. […] to Barry Cooper, a former drug enforcement cop turned police accountability activist, a police dog needs to give […]

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