On Thursday, the St. Paul Dog Training Unit celebrated the graduation of a class of 12 new K-9 cops. The German shepherds traveled from abroad to undergo the specialized training and are now bound for law enforcement careers with various police departments across the state (some will venture into Wisconsin, as well). Completing the rigorous 12-week course is an accomplishment that is expected of only one-fourth of entrants. Dog trainers say their success depends on a keen understanding of the animals’ psychology and plenty of positive reinforcement, reportedly.