Drug Dog Trainer Barry Cooper Police Dogs And False Alerts

How To Trick A Drug Dog
June 28, 2023 Barry Cooper 24 Comments

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In 2006, former narcotics officer and current criminal defense expert witness Barry Cooper was the first to blow the whistle on police dog false alerts, which he personally learned to trigger as an expert canine trainer (often shorthanded as “K9” or “K-9” by police).

Enjoy this comprehensive study of police dogs, which includes videos of false and true alerts.

Police canine false alert

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

Police canine true alert

See the difference?

Another True Alert

Notice how the handler allows the police dog to work and does not manipulate the movements or alert of the canine?


The ability to detect narcotic odors is not specific to just police dogs. All dogs have the ability to smell narcotic odors.

Properly trained police dogs are different because they can 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 canine detects the odor of a narcotic during a search, police dogs communicate 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.

Police dogs and odor separation

Never Get Busted

Unlike humans, trained police dogs have the ability to separate odors mixed together. When presented with a bowl of stew, a human sees all the different ingredients but smells just one odor. A police dog can smell, distinguish, and separate each ingredient contained in the stew simply by sniffing it.

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. However, this “odor separation process” takes time and police dogs cannot properly separate odors if rushed.

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 canine 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 police dogs work

K9 Dog Sniffing Car

Police dogs must also have room to work through invisible scent cones created by a multitude of odors surrounding the vehicle. Canines must have this space to track the odor’s source. Canine 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 canine’s head instead of allowing the dog to work freely. While teaching canine 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 canine lacks motivation to search a car, and stares at traffic instead of searching for drugs—especially in front of peers.

False alerts

K9 Dog on Alert

After police dogs have alerted, the handler encourages them 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 during 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 canine to be considered “dirty.” A dog that is dirty means the canine will scratch on anything to get its reward.

If drugs are located, the canine 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.

What to do if police dogs search your car

K9 Dog Sniffing on Mini Cooper Hood


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

Anytime police dogs are deployed to search your auto, announce loudly and boldly that you are aware police can make their canine 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.

How to store your stash


Weed on Hands

Police dogs cannot smell through material. Odors permeate out, creating a scent cone. Almost everything has microscopic pores for odors to permeate, even plastic baggies.

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.

However, lead is a heavy metal and nonporous. The trick is that if you hide your stash in a lead box, the police dog’s handler will become suspicious.

Temperatures also affect permeation. Colder temperatures slow permeation, so freezing your stash in a block of ice slows the permeation to almost nothing. However, those blocks of ice could also make a smart canine handler suspicious.

So, you must 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, glass, oils, and cold temperatures are all good because they all slow permeation.

Trying to mask odors does not work. So if you place your herb in a plastic baggie, spray it with perfume, seal it in plastic tubing, then drop it in your auto’s fuel tank, a scent cone will develop on the outside of the fuel tank. The canine will enter this scent cone and smell the plastic baggie, the gasoline, the perfume, the plastic tubing, and the marijuana. This explains how my canine detected hundreds of pounds of marijuana hidden in gasoline tanks.

Little-known fact

Canines 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 worse than the cages police dogs sleep in. Stay safe out there and NeverGetBusted.

And Remember It’s not the dog’s fault.



Consult with Barry Now!

Two fantastic articles covering Canine False Alerts:



24 People reacted on this

  1. 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!”

  2. 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.

  3. 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?

  4. 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.

    1. 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!

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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?

  10. 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?

    1. If the police did not have probable cause to detain the driver and occupants, they are in violation of Rodriquez vs. United States. Rodriguez v. United States was a United States Supreme Court case which analyzed whether police officers may extend the length of a traffic stop to conduct a search with a trained detection dog. In a 6–3 opinion, the Court held that officers may not extend the length of a traffic stop to conduct a dog sniff unrelated to the original purpose of the stop.

  11. Is there a specific distance that a drug canine can smell meth in ice form (18grams worth).

    Thank you

    1. The distance a dog can detect your stash depends on how far the scent cone extends from your stash. I’ve seen dogs track through scent cones with the source being 10 yards away. Good question.

  12. Lol you are a discrace to even say you wore a badge. But lol the things you are saying are so wrong it is so funny, dope dealers do exactly what this idiot says so when you come through my area I can bust your rear. Then you can go ahead and call this idiot for legal advice. A K-9 nose smells 120 million times better than we do. So do the math I can smell the marijuana you are transporting without a dog so keep coming up with stupid ways of trying to transport dope. I will be there and the other great officers of this nation to lock you up and take your money and your vehicle and anything else we can seize. Not to mention you are killing people. Keep up the good work dumb ass, see you soon. Oh and the next time one of you idiots need help don’t call the police call your local crack head and see how it goes.

    1. aaahhhhh just came across this “AHOLE” of an officers comment. You realize you are a servant of the people… not politicians or big pharma.. right? over 85% of the population want pot and all its associated LEGALIZED, yet you want to threaten, menace, disgrace, steal, and incarcerate the citizens that pay for you to eat, pay for you to have a roof over your head, and have internet for your teenage son to masturbate to Gay asian ass porn, because of your Jacked up moral belief system. What an idiot. You are the typical “I know what’s best for everyone around me, better than they do” jackass that most of run into, with a gun on their hip, and a badge that makes you think you are some Judge Dredd (yeah, just like that idiot Stallone) the iq of a peanut. THe ONLY thing that keeps the citizens from removing you from your self induced power trip is out of control legislatures, giving WAY too much power to these morons with limited to no education, but a loaded gun and radio to bring more guys with guys, to kill innocent civilians that question their authority, to dictate any judgement or self professed guidance on anyone. The brownshirts of nazi germany were eventually rooted out, and destroyed… we can only HOPE that you and officers LIKE you, are eventually removed from power, and given a job where you belong… repeat after us “Welcome to McDonalds drive thru, may I take your order?” for you deserve NO job were you have any power over your fellow citizens. Hopefully officers that know their position in life is to protect the citizens that pay their way in life, replace the likes of you at every corner . Some officers – the intelligent ones – know the drug war is only a way forJ the GovMint to felonize the entirety of the citizenry, and remove their rights, property, jobs, self worth. Just an avenue of suppression of a free society…. that is NO longer free.
      85% of the population of the US want MMJ legalized, yet the false “representatives” do NOTHING to represent this fact.
      The US incarcerates more civilians than Russia, China, North Korea, and Venezula …. combined!
      This is NOT a free society… nor a free country, any longer. US civilians have been the frog in the pot of water…. with the temperature raised 1 degree every month…. for 40 years…. Now it seems normal to have a police state, legalized theft(asset forfeiture), 60% taxation and out of control officers killing, maiming and illegally arresting civilians daily, all under the guise of “were are here to protect you” …. kinda fucked up, when the person I need protecting from, is YOU.

    2. Now I dont bash police I have many friends that are police some being k9’s and I personally know there is a command depending upon the language your dog is trained you can say and he will act like it was a positive hit when it’s not just so you can search and say you have probable cause, you as a officer though should act in a higher manner than you just did you should hold your self in a higher manner than that I’m disappointed in you but some things you said are true also you should never have said call your local crack head come on if your in the job for a calling and not for power you should want to help people smh

  13. The distance a dog can detect your stash depends on how far the scent cone extends from your stash. I’ve seen dogs track through scent cones with the source being 10 yards away. Good question.

  14. Hey Barry, is the dog in the Utah $500,000 case a “trashy” dog? Dog allegedly alerted on the vehicle stopped for following too closely. No drugs were found, but UHP is trying to keep the guy’s $500,000. Unbelievable the way cops lie when money is involved! The lawyers should hire you as an expert witness ASAP–if it’s an illegal search based on the dog, doesn’t that make the $500,000 “fruit of the poisonous tree” or whatever? Guy’s name is Kyle Savely, lawyer is Jim Bradshaw of Brown, Bradshaw & Moffat.


  15. Hi Barry, question didnt use turn signal within 100′ but did have it on just not soon enough i guess. Indiana officer pulls us over gets license and insurance of my boyfriend and has him get out of car. walk him behind car comes to passenger side asks me for registration. then goes back to driver and tells him hes calling the dog within a minute 3 more cars show up. officer walks dog around twice the first time i hear a loud thud on driver door and then a light bark and i guess dog laid down. he repeated this going around and when he came to drivers side agian dog hits thud was quieter this time. everyones pulled out of car its searched. there were drugs found under the passenger seat. they was in a ziplock and then in a leather backpack under seat. are they supposed to hit the door.

  16. Please help! I was pulled over last 4th of July. I sniff test was done and the dog alerted where my puppy was sleeping. Are they allowed to sniff while another dog’s in the car?

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