Roberts is primarily based in
New York City, where he regularly appears in theatrical productions.
Off-Broadway he has appeared in a
revival of
Lanford Wilson's
Burn This, opposite
Edward Norton and
Catherine Keener; in
Adam Rapp's
Nocturne, for which he was nominated for a
Drama Desk Award; and in
Caryl Churchill's
A Number, opposite
Sam Shepard and later
Arliss Howard, among others. Roberts' film work includes the screen
adaptation of
Michael Cunningham's
A Home at the End of the World, and supporting roles in
Walk the Line and
The Notorious Bettie Page, among others. He had a regular role on the
Showtime drama The L Word. He starred in the
AMC original series
Rubicon as Miles Fiedler, a genius
intelligence analyst at a national
think tank. He appeared in twelve episodes of
The Good Wife as Owen, the
gay brother of
Alicia Florrick (
Julianna Margulies). He has also made many appearances on
Law & Order and its spinoff,
Law & Order: Special Victims Unit. He also appeared in a crossover arc between
SVU,
Chicago P.D. and
Chicago Fire as
serial killer Gregory Yates. From August 2012 through March 2013, Roberts was in the cast of
The Walking Dead as scientist
Milton Mamet, who studies "walkers" (zombies). From 2013 to 2015, he played Eliot Delson on
Unforgettable. ==Personal life==