Who is Tanner in the motion picture, The Thin Man?

Thanks to his connection with Julia, Tanner works as a bookkeeper for Clyde Wynant. Although he has previously served time in jail, he is not involved in the murders. Tanner assists Julia in stealing money from Wynant. As the number of deaths increase, he tries to erase all evidence of his partnership with Julia so that he will not become the killer's next victim.