hospital. anyone will feel a huge urge to act about what they've seen. a smoking gun, perhaps not because it doesn't point. it doesn't connect this directly to bashar al-assad. that's what the videos can't show us at the moment. >> as you've said before, some of these videos, many of them have been seen on youtube before. they've been out there on the internet. they put them all together to show to this group of senators and to others who may be voting on whether or not there should be some military action in syria. >> reporter: they've focused on things like the eyes. pupils. when a human is exposed to nerve gas like sarin it contracts the eyes. they focused on the medical