>> correct. >> are they pictures, are they like what we call screen grabs, they are some video or actual pictures of someone on the street or like head shots, mugshots unrelated to the actual incident? >> there are multiple pictures that could have been taken from any number of cameras that show these two men in different perspectives, from different angles. some head-on, some of them from behind. and there may be video, greta, that links the men in these pictures to the events of monday afternoon. there have been reports that a surveillance camera at a department store on boylston street had captured images of a man place ago backpack down and then walking away right before the explosion. it's quite possible the fbi saw that video and then went back and found the man in that video and then found another man next to him, and is now linking those two men to this series of events. again, we don't want to describe