H. Michael Steinberg has 38+ years of experience practicing Colorado criminal law. Mr. Steinberg strives to stay current with the ever changing aspects of criminal law issues and updates resulting in his extensive knowledge of successful criminal defense as well as appellate work. He is also an active member of the National Association of Criminal Defense Lawyers, the Colorado Criminal Defense Bar Association, the Colorado Trial Lawyer's Association, and the Colorado and Arapahoe Bar Associations.
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Colorado Law – The Police Use A Dog Sniffing Dog – What Next? By Colorado Criminal Defense Lawyer

First Some Basic 4th Amendment Search and Seizure Law

Colorado Dog Sniff Search LawA Dog Sniff Alone Is NOT A Search Under State And Federal Law

The Federal and State Constitutions give people the right to be free from unreasonable searches and seizures. U.S. Const. amend. IV; Colo. Const. art. II, § 7; A warrantless search is presumptively unreasonable, violating the Fourth Amendment unless it falls under an exception to the requirement
of a search warrant where there is a reasonable expectation of privacy – such as your car.

While the standard of proof know as “reasonable suspicion” is necessary for the police to “dog sniff” your vehicle, the sniff itself is not considered a search. Furthermore, a drug sniffing dog who does “alert” to the presence of illegal drugs in a vehicle can be used to support a finding of probable cause to conduct a legal search of that vehicle.

Reasonable suspicion means the police must have…

“specific and articulable facts, greater than a mere hunch, to support’ their belief that the person to be stopped is or may have been involved in criminal activity.”

A Court determines that reasonable suspicion exists by looking at..

“the totality of the circumstances, the specific and articulable facts known to the officer at the time of the encounter, and the rational inferences to be drawn from those facts.”

The “automobile exception” allows law enforcement with probable cause to believe that the vehicle contains evidence of a crime without obtaining a judge signed warrant.

Finally, both the United States and the Colorado Supreme Courts have ruled that deploying a well-trained drug-detection dog during a lawful traffic stop does not implicate the Fourth Amendment since, again, a ‘sniff is not a search.”

For many years it has been the law that if the police have reasonable suspicion to believe there are unlawful drugs in your car, they would summon a K-9 Unit – Drug Sniffing Dog to the scene to search for drugs.

Dogs trained to detect marijuana as well as other drugs provided the necessary probable cause for a thorough search of the vehicle. If illegal drugs were located, would be seized and the driver and, perhaps, other passengers arrested and charged.

Since The Passage Of Amendment 64 In Colorado – Everything Has Changed

The passage of Amendment 64 legalizing the possession of an ounce or less of marijuana for citizens 21 years and older changed everything. Marijuana has been decriminalized in Colorado. As of 2012 possession is not only not a criminal violation it is also not a civil violation.. Colo. Const. art. XVIII, § 16(3)(a) (Amendment 64

So Exactly What Changed In Colorado Dog Sniff Cases? What Does This All Mean?

Before Amendment 64 a drug sniffing dog trained to alert on the presence of drugs included the then illegal drug, marijuana. When the trained animal performed “an exploratory sniff” on your car and alerted to an unlawful substance, that formed the basis for a “there and then” search of your car.
Your “reasonable expectation of privacy” under the 4th Amendment could be breached and the search conducted under these circumstances.

Are Colorado’s Drug Sniff Dogs Being Retrained To Overcome This Issue?

Today it is unclear whether a drug sniffing dog can be trained to stop alerting to marijuana. If the police represent that a drug sniffing dog has been untrained, a criminal defense lawyer’s job is to challenge that representation in court.

The District Attorney who argues that the deployment of a “drug sniffing” dog is trained to detect illegally possessed drugs must now “credential the dog and the dog sniff alert” was not in part or in whole, the result of the detection of the presence of marijuana.


  1. A vehicle must be legally stopped before the police can conduct their investigation. That stop also cannot be “an unreasonably prolonged traffic stop.”
  2.  During the investigative phase following the stop, the State must establish, under the totality of the relevant circumstances, there was reasonable suspicion to conduct a dog sniff of the vehicle.
  3. If the drug sniffing dog is “credentialed” meaning that the dog has been retrained NOT to alert to marijuana, a police officer may develop probable cause to conduct a search. (Probable cause means ‘the facts available to the officer would warrant a person of reasonable caution in the belief’ that contraband or evidence of a crime is present.“ Probable cause is a commonsense concept that requires judges to consider the totality of the circumstances to determine “whether a fair prob of a particular place will reveal contraband or evidence of a crime.’”