You really should've known. He always kept to himself, he never talked or showed his face, and he only ever hung around a few people. These people just had to have the most information on Task Force 141.

Everyone thought Roach was just shy, or he didn't like people very much. Turns out he just doesn't like your people, or that's what it seems like to you now that his gun is aimed at your head. Apparently he's the traitor that your team heard about. And even now, he's still not saying a word.