Gilliam's film career began in the early 1990s. He has starred in award-winning films such as
Still Alice. His other film credits include Sergeant Sugar Watkins in the 1997 action film
Starship Troopers and Sergeant Steven Altameyer in the 1996 film
Courage Under Fire. Gilliam has had a number of recurring roles on television, including during the seventh season of
The Cosby Show as Aaron Dexter, boyfriend of
Erika Alexander's character, and as Alan Deaton on
Teen Wolf. His most prominent role has been on
The Wire. In 2008, he attracted attention for criticizing the show being overlooked for Emmy nominations despite its critical success. He has had a number of guest roles in other shows such as
CSI: Miami,
Nurse Jackie,
Skins,
Person of Interest, and
The Good Wife. He played Clayton Hughes on
Oz. In May 2014, Gilliam was cast as
Father Gabriel Stokes in the fifth season of AMC's
The Walking Dead. Along with
Chad Coleman and
Lawrence Gilliard Jr., he is the third
The Wire alum to join the series. Gilliam has acted on stage, playing
Prince Edward in a 1993 production of
Richard III. He played the title role in
Othello, first in 2010 at Boston's
Commonwealth Shakespeare Company Gilliam has stated that he prefers acting on the stage although he loves his work in film and television: "Acting for the stage is a lot more fun to do. There is instant communication with the audience. An actor can tell whether or not he or she is connecting with an audience or whether they understand what's going on." ==Personal life==