Jesse L. Martin (AP Photo/Evan Agostini)

[Hollywood Reporter]

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.

AP Photo/Evan Agostini

The CW is rounding out the cast for The Flash.

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 potential love interest — West came up through the foster care system and took Barry in after his mother’s slaying and father’s imprisonment. He believes in Barry and supports his efforts to prove his father’s innocence.