Is it just me or is this guy talking on camera, starts off with "I don't want to upset people but I don't think things should be hidden", then every story is hearsay, and he's the one telling people a baby got shot. I dunno, maybe he was there and just wants to talk, entirely possible, but he just comes across as some attention seeking a-hole who wants to tell a story on camera.
They do seem to now think it was just the one guy, of course early on you'll get so many different storys that they'll probably think its two guys. Two different types of guns, tall people think he's short, short people think he's tall, you end up with two different descriptions. Sounds like he might have used a shotgun AND left other guns in the theatre, which somewhat explains how so many people got shot.