Police departments in Texas and around the country routinely use trained dogs to sniff the air around vehicles during traffic stops, and the courts have ruled that this does not violate rights protected by the Fourth Amendment. One of the most important rulings dealing with the admissibility of evidence discovered after a K9 unit alert during an air sniff was handed down by the U.S. Supreme Court in the 2005 case Illinois v. Caballes. In that case, the justices ruled that the Fourth Amendment did not apply because the dog alerted to the presence of an illegal substance and did not violate the defendant’s expectation of privacy.
Pulled over for speeding
The case involved a man who was pulled over for speeding in Illinois. A K9 unit alerted while sniffing the air around the man’s car, which led to the discovery of marijuana. The case made its way to the U.S. Supreme Court after the Illinois Supreme Court ruled the search illegal because the man had been pulled over for speeding and police had no reason to believe that he was violating drug laws.
The U.S. Supreme Court ruling makes it clear that police officers can use dogs to sniff the air for the presence of drugs during a legitimate traffic stop. However, the justices said in their ruling that traffic stops cease to be legitimate when they are prolonged unreasonably to give K9 units time to respond to the scene. This is why experienced criminal defense attorneys may study the timeline very carefully when their clients are charged with drug possession or trafficking because a K9 unit alerted during a routine traffic stop. This was not a factor in Illinois v. Caballes because the officer who initiated the traffic stop was still writing a speeding ticket when the police dog arrived.
Consenting to searches
Fourth Amendment arguments are rendered moot when suspects give police officers permission to search their vehicles or admit that they are transporting illegal drugs. This is why an experienced criminal law attorney may advise their clients to not consent to searches or make incriminating statements even if their situations seem grim. Instead, attorneys could urge individuals pulled over by the police to state that they do not consent to any searches and wish to remain silent.