Truth be told, practically anything can be an effective police partner with the right sort of training, in the right type of situation. Many pokémon are even trained for particular specialties, such as psychic-types for investigation, canines and flying-types for search and rescue (as they’re hardier than psychics), ghost-types for psychic crimes, and so on.
In mawile’s case, while the species can in general be effective for interrogation (given their usual special abilities), it wouldn’t be unusual at all to find one on the beat as well, given their size and ability to startle fleeing suspects.
So in short, absolutely. Best of luck!