We've been hearing about casting for The Hunger Games: Mockingjay Parts 1 & 2 for some time now. While we're still waiting to hear word on who will play Tigris, Lionsgate has gone and announced Prison Break's Robert
Source:
http://www.hungergamesbuzz.com/panem/hunger-games-mockingjay-cast-character-not-in-the-books-the/