CNN Starting Point May 30, 2013 11:11:00
Understanding how and why it happened, making sure that those who visit the park are really very safe. >> something that doesn't look like a prank, the ricin letters now to mayor bloomberg. that's sort of an interesting and frightening trend. you see these things kind of come up in twos and threes it feels like. what do you make of these letters to bloomberg and to also the person who runs as mayor against illegal guns and what kind of a serious threat that may be? >> the problem here is that the ricin recipe is basically the components of very easily obtained. it comes from caster -- ground u...