ABSTRACT
Only the rst of these situations, adapted from parts of cases and studies, describes a canine function-tracking-that existed before 1970. Scienti cally conducted scent lineups date from after 1990. Remote explosives detection systems using dogs have been studied with regard to landmines and have begun to be used for airfreight. The rst dog devoted solely to nding cadavers was deployed in 1974, the rst arson dog in 1986. Even the tracking situation described in the rst scenario involves the use of a device, a scent transfer unit, which was patented in 1998.1
Police dogs today look much as they looked 50 years ago, though they now often travel in crates rather than in the backseats of squad cars, but it would be a mistake to think that there has not been a considerable amount of change in police work involving canines.
