the official says investigators they know of from overseas and no conclusions about what may have radicalized them. there's that, but that's only the beginning. in a moment, you're going to meet the man who came face-to-face with the bombing suspect in his boat. his account different from what we've all been hearing. just imagine what you'd do in his shoes. you go into the backyard and see this, only not from a chopper, not in black and white, up close. in bloody, living color. your' going to hear from him in the hour ahead. you'll also hear from a watertown man who photographed the firefight on the street outside of his house. this is the fight that took place very early morning. the images, utterly breathtaking. this one showing the two suspects taking aim at police at the end of that chase thursday night. another shows the police suv that a police officer used in a