TODAY | April 17, 2013
>>> let's bring in nbc's justice correspondent pete williams into the discussion. good morning to you.
>> good morning, matt.
>> the first picture lester showed us, the immediate aftermath of the explosion taken from across the street looking down and as we go through the images you'll see a man in black, his clothing has been shredded and he is running away from the scene. are investigators looking at that? this is a different image, it's not the one i was looking for. okay, here is the one we're talking about. are investigators looking at this guy as a guy who may have been involved in terror or running away from terror?
>> i'd say running away . these pictures were taken by a man named ben thorndike who has a window right over the finish line and when we looked at his pictures we saw the man and the impact of the blast has partially ripped his clothes away. the same thing was said about this exchange student .
>> the saudi national.
>> it could be the exchange student , they're not sure but in any event the fbi no longer considers him of interest here, they think he was just a victim.
>> let's go to the other series of photos, we're looking in at the mailbox along the race route near the finish line , some sort of package, a bag at the foot of that mailbox. we zoom in on that one, and then the immediate aftermath of the explosion it looks like it took place almost exactly in that spot. what are you hearing from investigators on this?
>> they're definitely looking at this picture. they have other pictures that show the same thing so the question is whether the bombs were placed in those basic garbage or shopping bags and then that green thing in the picture is, in fact, a trash thing, whether they were set there to appear less conspicuous conspicuous. they believe the bombs were carried to the scene in black nylon duffel bags, i'm told their weight was up to 20 pounds so that is definitely a possibility. they're not sure. that's one of the reasons they want all these pictures.
>> pete, quickly, the type of device used, we know we think they were pressure cookers , was this perhaps foreign terrorism or perhaps homegrown terrorism ?
>> for sure pressure cookers because you can see the brand name of the pressure cooker in one of the pictures and the specifications of how much pressure it can build up but unfortunately, no, the recipes for this device are used for decades, all over the internet. it's not hard to find them. it doesn't lead them one way or the other.
>> pete williams in washington thank you.