Dallas Drug Defense Attorney Explains When a Dog Sniff Violates Your Rights

Drug Crimes:  When Is A Dog Sniff A “Search” answers Dallas drug defense attorney John Helms

If you love dogs like I do, you know that, when dogs first meet a person or another dog, the first thing they do is to smell the new acquaintance.  Some breeds of dog have remarkably good senses of smell.  For that reason, law enforcement has used trained dogs for many years to detect illegal drugs by smelling for them.  This is called a “dog sniff,” says Dallas drug defense attorney John Helms

Can that sniff violate your Constitutional rights?  The answer is that, in some cases, it can.

The Fourth Amendment to the United States Constitution prohibits the government from conducting “unreasonable” searches and seizures.  Whether an activity is a “search” for purposes of the Fourth Amendment depends not on the activity itself, but on whether the activity seeks information and intrudes on a person’s “legitimate expectation of privacy.”

In a series of cases, the United States Supreme Court has held that the following types of dog sniffs are NOT “searches,” so that they do not violate the Fourth Amendment:

-Sniff of a car that has been lawfully stopped by the police.  See United States v. Caballes.

-Sniff of a car stopped at a drug interdiction checkpoint.  See City of Indianapolis v. Edmond.

-Sniff of luggage at an airport.  See United States v. Place.

In each of these cases, the Supreme Court has emphasized that people do not have a legitimate expectation of privacy in the air around a car or luggage.  If all a dog does is sniff the air to determine whether there is an odor of illegal drugs, the Fourth Amendment is not violated.

In Florida v. Jardines, however, the Supreme Court held that a search occurred when police officers brought a dog to the porch of a suspect’s house to sniff for drugs.  The Supreme Court justified this because the law has always recognized that people have a high expectation of privacy in their homes–much higher than in a car or at an airport.  This meant that the drugs found in the home were suppressed and could not be used as evidence.

In an interesting recent case called People v. McKnight, the Colorado Court of Appeals held that, under Colorado law, a dog sniff of a car was a search because the dog was trained to detect a number of illegal drugs and marijuana, but small quantities of marijuana were legal for adults to possess in Colorado.  The Colorado court held that a search had occurred because motorists in Colorado have a legitimate expectation of privacy in their cars for conducting lawful activity, and the dog was trained to “alert” if it smelled marijuana, the possession of which was lawful.  The court therefore suppressed the controlled substance and drug paraphernalia they found when they searched the truck after the dog alerted.

One technique that police officers sometimes use is to call for a K-9 unit to come to a traffic stop to sniff a car even if there is no indication of drug use.  Since the dog sniff is normally not a “search,” they can generally do this.  However, in a recent case called Rodriguez v. United States, the United States Supreme Court held that the police violate the Fourth Amendment protection against unreasonable SEIZURES if they detain the driver after legitimate law enforcement activity is over in order to give the K-9 unit time to get there.


The law of searches and seizures is very complicated.  If you or a loved one has been charged with a crime following a search, you should contact a lawyer who has expertise in this ever-changing area.  As a criminal defense lawyer who has successfully fought these battles many times, I can tell you that it is always important to hire a skilled and experienced lawyer to protect your Constitutional rights.

If you or a family member have been charged with a drug crime or any other drug related crime in Dallas or the nearby counties and have any questions about drug laws, contact Dallas drug defense attorney John Helms at 214-666-8010 or fill out this online contact form. We can talk about the situation, how the law could apply in your case and the best legal options to protect your rights and maintain your freedom.