its of intelligence like there is training for the rebels or maybe we saw a pew trucks. you have to have a lot more if you're an intelligence profession to put the president and secretary of state out with this level of confidence. i think they know a lot more than what they're telling us. >> david, i mean again, you've investigated crash sites. even if there is this electronic information, signals, intelligence. only tip of the iceberg is known at this point what the u.s. and others may have. how important is that crime scene? how important is the actual physical evidence? >> it's extremely important. even with that intelligence, it's surmizinsurmizing. it's saying because this, we know this. we know this. what really ties that together is the chain of evidence and the chain of custody of that evidence. >> you argue the black boxes are incredibly important? >> absolutely. as is any of the physical evidence on the site. for example, the evidence that the shrapnel went through the aircraft from the outside in. that's extremely important. and that could definitely be compromiseded here. ?