Police dog
Different breeds of police dogs tend to be good at different things.  However, any good police dog should be intelligent, aggressive, strong, and have a good sense of smell. Many police dogs are male and unneutered (because neutering can make a dog less aggressive).  However, there are female police dogs, which are used for rescue, tracking, and locating bombs and drugs. German Shepherd Dogs and Belgian Malinois are the most commonly used; however, other dog breeds (and their specialties) include: