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Probable Cause/Plain View Doctrine?

Richmond, VA |

I've read that the smell of marijuana is probable cause for a search of one's vehicle, but I've also read about something called the Plain View Doctrine, and I was wondering about "...if evidence of criminal activity or the product of a crime can be SEEN without entry or search." Since marijuana odor cannot be SEEN, is that really reason enough to search your vehicle?

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Attorney answers 3


The general rule is that the police may not search your home or your person without a warrant. There are multiple exceptions to this rule. One of these exceptions is the Plain Smell Doctrine. If an officer pulls you over for a valid reason and can smell marijuana eminating from your person or your vehicle, the officer does not need a warrant to search your person/vehicle.

Another exception to the warrant requirement is the Plain View Doctrine. If an officer pulls you over for a valid reason, or is even just walking past your vehicle and can clearly see a baggie of what appears to be marijuana sitting within the car, the officer does not need a search warrant under these circumstances.

These doctrines work independently of one another. You do not need to also see marijuana in order for the plain smell doctrine to apply. Hope that helps.

The information provided herein is intended solely for educational purposes and does not create an attorney-client relationship. Please contact a local attorney for assistance with your matter.


As long as the officer can articulate that through his training and experience that he knows the smell of marijuana there is plenty of case law supporting the "plain smell" doctrine.

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Florida v. Harris was decided this past week. Interesting blog article online:

“Probable Cause On A Leash”
Published 1, February 23, 2013

-Submitted by David Drumm (Nal), Guest Blogger

The United States Supreme Court recently issued a unanimous (9-0) decision in Florida v. Harris (2013) that deals with probable cause and drug detection dogs. The Court overturned the Florida Supreme Court ruling (pdf) and held that the police officer had probable cause, based on the dog’s reliability, to search Harris’s truck. The Court also held that: “If the State has produced proof from controlled settings that a dog performs reliably in detecting drugs, and the defendant has not contested that showing, the court should find probable cause.”

When testing a dog’s detection reliability in a “controlled setting,” a key factor would be whether the test is double-blind. That is, neither the dog and the handler know where the drugs are hidden. As is often the case however, it is the handler that designs the test and the handler will cue the dog. Lawrence Myers, a veterinarian and neurophysiologist at Auburn University who is an expert on dogs’ olfactory capabilities, notes the handler “can’t help” but cue the dog and skew the training.

The unconscious cueing of animals is known as the “Clever Hans Effect.” Clever Hans fascinated audiences solving mathematical problems by stomping its front hooves. An investigation determined that the horse was responding to subtle, subconscious cues from its handler to indicate when to start stomping and when to stop.Clever Hans

In a UC Davis study, researchers found that “detection-dog/handler teams erroneously ‘alerted,’ or identified a scent, when there was no scent present more than 200 times — particularly when the handler believed that there was scent present.” Even the best trained nose can be impacted by the handler. Anita M. Oberbauer, chair of the Department of Animal Science and the study’s senior author, said: “Dogs are exceptionally keen at interpreting subtle cues, so handlers need to be cognizant of that to optimize the overall team performance.”

Of course that implies that the handler wants to optimize the overall performance. Police have strong incentives to use a drug detection dog that alerts promiscuously. Asset forfeitures are a powerful incentive for cash-strapped police departments. When an officer’s performance reviews and potential promotion are based, in part, on the number of drug busts and drug seizures made, and the use of a dog prone to false positives is to an officer’s personal advantage.

K-9 teams use many tricks to conceal the dog’s supposed “alerts.” If the scene is being videotaped by a police dash-cam, the officer will stand between the camera and the dog, or take the dog to the front of the suspect vehicle where the dog is out-of-sight. Many police departments has stopped recording K-9 teams because “the dogs don’t alert when the cops say they alert.” Handlers also use excessive verbal encouragement and lavish praise to get the dog to respond.

An investigation of three years of data by the Chicago Tribune found that: “only 44 percent of those alerts by the dogs led to the discovery of drugs or paraphernalia.” When considering Hispanic drivers, the success rate fell to 27 percent. Justice Kagan, writing the opinion of the Court, noted that in such cases, “the dog may have smelled the residual odor of drugs previously in the vehicle or on the driver’s person.” Such an hypothetical claim is a little too convenient and should raise suspicions about its validity. According to J. Kagan, a dog’s alert “establishes a fair probability—all that is required for probable cause—that either drugs or evidence of a drug crime … will be found.”

The Supreme Court is set to decide Florida v. Jardines, a case involving a drug detecting dog that was brought up to the front door of Jandines’s home.

I am trying to give you a general answer to your question. We do not have an attorney-client relationship by this response on the avvo website. I have not been retained to represent you. I am licensed to practice law in Kentucky and in federal court in this state and the Southern District of Indiana. You need to seek legal advice from an attorney licensed to practice in your area..