good evening, everyone, i'm erin burnett in boston and we begin out front tonight with breaking news, a possible suspect in the boston bombings. here's what we know at this moment. according to sources who talked to cnn, authorities have a poss based upon analysis of video of a department store, lord & taylor department stores right near the second blast. federal investigators have made in their words significant progress in the case. the possible suspect is being described as a male who was wearing a white baseball cap backwards, a light colored hoodie and a black jacket. we're awaiting an fbi press conference within the hour and we're going to bring that to you live as it happens. i want to bring in our national