They've already changed up a good bit, but comic version he never really turned bad per se, his real name got leaked and the terrorist group ended up killing his parents. He snapped, killed/maimed a bunch of them and became very unhinged after that. Combination of parents death and trying to live up to the Cap legacy did a number on his psyche.
Something definitely pushes him over the edge on the show, could just be failure to complete the mission, but might end up having Battlestar get killed that starts the implosion.