So, basically, K9 is a dog that is specifically trained for one purpose and this is to serve the police and other law agencies. These dogs are trained in locating drugs and explosives, finding a missing person, searching for evidence on a crime scene, and attacking people pointed out by the police. Police dogs are required to remember verbal cues and hand signs. The most regularly used breeds are the German Shepherd, Belgian Malinois, Bloodhound, and Dutch Shepherd. In Matthew’s case, his best pal was the German Shepherd who was a K9 police dog. But the department was about to do something really grave with Ajax.