A Savannah-Chatham police investigative unit teamed with members of the public to arrest a five-time convicted felon on drug trafficking charges, worked with the city to close his business, and is partnering with federal officers for additional prosecution.Troy Dexter Williams, 45, has been charged with trafficking large amounts of cocaine after a Tuesday raid of his residence and his body shop, both on the 300 block of West 32nd Street and another business on the 1500 block of Montgomery, said Julian Miller, police spokesman.