Something very significant happened to make Carter as angry and emotional as he was. Clearly he had seen that sketch well before the last few days, and had seen the video as well. Simply the holding of a press conference wouldn't cause him to be in the state he was. Whatever happened - it's personal to him, beyond his obvious desire to catch this guy. Something affected him deeply and profoundly. He seemed to be horrified, angry, and even incredulous - like he'd been shocked and appalled by some new development. Either someone he knows, or a person in a position of trust to the girls or children...there's a sense of betrayal there.