The selection of a police dog is a meticulous process that considers many factors, including physical attributes, temperament, and trainability. Breeds such as German Shepherds, Belgian Malinois, and Labrador Retrievers are popular choices due to their intelligence, drive, and eagerness to work. Handlers often evaluate potential candidates by observing their behavior in various scenarios, such as social interaction and reaction to different stimuli, to ensure they can perform well in the demanding environment of police work.