Fox’s Batman prequel Gotham is staffing up, with TV writer/author John Stephens coming on board as an executive producer. The assignment is part of an overall deal Stephens has signed with Gotham producer Warner Bros TV. Gotham, from The Mentalist creator Bruno Heller, has a series commitment and is fully expected to go to series. Stephens, repped by UTA and and Jackoway Tyerman, previously worked on the WBTV series Gossip Girl (exec producer) and The O.C. (co-exec producer).