Booker worked at the police station in the GameCube Animal Crossing, and now works as the gate guard in Wild World and City Folk. He is a nervous dog, and frequently mumbles. He won't question you for taking everything from the town lost and found. He will tell you what's new in your town. He also will let you change your town flag if you want.
In New Leaf, Booker will work in your police station if you choose the 'classic' design.