This year, the U.S. Supreme Court has decided two cases involving drug dog sniff tests. In the first case, Florida v. Harris, the Court ruled that a positive test by a drug dog whose abilities are supported by training and testing records, and whose abilities are not undermined by other evidence, is sufficient for probable cause to search inside a car. In the second case, Florida v. Jardines, the Court ruled that a sniff test by a drug dog on the front porch of one's home is a search.
Florida v. Harris involved a drug dog test during a routine traffic stop. The officer asked to search the car he pulled over, and the driver refused to give consent. The officer subsequently performed a sniff test with a drug dog, and the dog alerted on the car. The officer concluded he had probable cause and searched the car. He found contraband, but not contraband the dog was trained to detect. Later, the officer pulled over the same driver in another traffic stop and conducted a sniff test with a drug dog again. The dog alerted on the car again and the officer searched but found nothing. The driver attempted to suppress evidence of the searches but his motion to suppress was denied. The Supreme Court held that if a State can produce evidence that a dog detects drugs reliably in controlled tests, and a defendant does not rebut that evidence, then a positive test will be sufficient for probable cause. However, a defendant may rebut evidence of certification and testing of a drug dog by offering evidence to challenge training standards or any problems with his particular situation. Then the issue of probable cause is decided by the totality of the circumstances.
Florida v. Jardines also involved a drug dog, but this time the question was whether using a drug dog to detect drugs from the front porch of someone's home is a search. If so, then the drug dog test would require a warrant. In this case, police took a drug dog to the defendant's front porch and the dog alerted to the presence of drugs. The defendant moved to dismiss this evidence in the trial court but his motion was denied. Here, the Supreme Court held that performing a dog sniff test on someone's front porch is a search. The Court explained its decision by stating that the "very core" of the 4th Amendment is the right to retreat into the home, including the curtilage, and "be free from governmental intrusion." The curtilage is the area immediately surrounding the home. Since the officers were in the defendant's curtilage, they had to have a warrant before they could use the drug dog.
These cases are split in that Harris is a win for the government while Jardines is loss for the government. Drug dog reliability can be presumed simply by certifications of controlled tests instead of reliability in the field. This makes it easier to introduce drug dog evidence in court. A police department could simply not keep records of field tests by drug dogs and therefore limit the amount of evidence a defendant could use to rebut the presumption of validity created by a certification. There are a few examples of the unreliability of drug dog tests. Of course, if decent field test records were kept by a police department, and the records terribly disfavored reliability, then that evidence might be sufficient enough to outweigh certification evidence in support of a defendant's motion to suppress.
Jardines tells us that a drug dog sniff test in the curtilage of a home is not sufficient and never will be for probable cause simply because the sniff test is a search and therefore requires probable cause. In this case, there must be other evidence to support probable cause before officers can obtain a warrant and search a home.