He'll play Detective West, a surrogate father to Grant Gustin's Barry Allen in the "Arrow" spinoff pilot from Greg Berlanti, Andrew Kreisberg and Geoff Johns. The network has enlisted Law & Order alum Jesse L. Martin to co-star in the Arrow spinoff built around speedster The Flash , The Hollywood Reporter has learned. Grant Gustin stars as Barry Allen/The Flash in the pilot, which will be an origin story similar to what producers did with Stephen Amell starrer Arrow. Barry, who appeared in Arrow's two-part winter finale, is described as a Central City assistant police forensic investigator who arrives in Starling City to look into a series of unexplained robberies that may have a connection to a tragedy in his past. Martin -- who played Det. Ed Green for nearly 200 episodes on the Dick Wolf procedural -- will portray Det. West, an honest, blue-collar cop who is a surrogate father to Barry. A soulful, funny and caring father to Iris -- Barry's po