heat, shock or friction. >> laura: steve rogerers is a former member of the fbi terror task force and terry from the counter terrorism division of the fbi. gentlemen, this is wild. it took the fbi 20 years to trackdown the una-bomber. how did they find this guy so quickly? >> well, this is a very interesting week. we heard all kinds of theories. this reminded people it's tremendous when you can find intact devices. also on any case no matter how complicated, you have to make sure you say with shoe leather and policework and pay attention to the tedious. today we hear on one device the fbi lab was able to pull a finger print. the una-bomber was never