The use of dogs trained to detect drugs is a common interdiction tool used by the police. Typically, if a properly trained drug detection dog alerts on the presence of illegal drugs, the alert itself may be sufficient to establish probable cause to search a car.
Recently however, in the case of Florida v. Jardines, the U.S. Supreme Court ruled that that the warrantless use of a police drug dog outside of one’s home, in an effort to determine if illegal drugs are present inside the home, is a physical intrusion into a constitutionally protected area. Thus, the use of drug dogs even outside the home is subject to the Fourth Amendment to the Constitution’s warrant requirement.
In Collin County, Texas this method is also employed in drug interdiction efforts by local law enforcement. Recently, the Fifth Court of Appeals in Dallas, relying on Jardines,
affirmed the trial court suppression of evidence where a drug detection dog was used on the front porch of a home and alerted to the presence of narcotics in the home. The police obtained a search warrant based on probable cause from information developed, in part, by the drug dog’s alert. In Texas v. Williamson the Court made clear Jardines will control the rule of law in curtilage searches where drug dogs are employed