ABSTRACT
K-9 units contribute tremendous value to law enforcement, search and rescue organizations, and society. Dogs are experts in locating hidden people and objects, like cash, cadavers, narcotics, and bombs. In general, canine officers generate goodwill in the community and may improve public opinion regarding officers, especially among youth. The importance of working dogs in criminal justice has amplified since the first use of war dogs on police forces sixty years ago. State, federal, and US Supreme Court cases have challenged constitutionality of criminal procedures involving K-9 units. Canines' sense of smell penetrates exterior barriers and dogs detect contraband; thus they have a similar effect as searches. During routine traffic stops canines may sniff the outside of any vehicle. One of the most controversial uses of canines is dog scent lineups. Canines may have superhuman talents, but they are neither invulnerable nor infallible. When canines have been killed in the line of duty, their deaths have been deeply regretted within departments.
