Approximately 17 years ago, the United States Supreme Court endorsed the use of drug sniffing dogs in a criminal investigation. A recent study at University of California has concluded that the basis of the Supreme Court's decision is nothing more than "scientific fiction”.

The study shows that drug dogs made over 200 mistakes when sniffing rooms that did not contain any essence of marijuana/pot during the testing process.  The animals, the researchers concluded, produced a high rate of false positive alerts when the handlers were conditioned to believe that drugs were in a specific location.   In short, the dog’s perception was influenced by the handler’s perception.

Moreover, a study at the University of Pennsylvania School of Medicine in 2004 was conceived to determine the capabilities of police officers to detect  the odor of packaged marijuana/pot secreted in the trunk of a motor vehicle.  Six of the nine participants could not discern the essence of marijuana/pot.   In another test each of the nine participants were unable to detect the smell of marijuana/pot coming from an exhaust fan at a grow house.  The study ultimately concluded that "blanket acceptance of testimony based on reported detection of odors of marijuana for probable cause is questionable"