about as tight as it can get in boston right now, erin. >> joe, i'm just looking at the latest information that we're getting. they talk about the bombs weren't sophisticated. the fbi saying this is something a lot of people could have figured out how to do. this suspect some complex creation, that they were ball bearings, zippers and blades inside of this. does that make law enforcement more afraid, that someone was able to kill this many people and get this far with apparently from what we understand no warning? >> right. it's a very disturbing thing, because remember, there was an element of coordination in that there was one explosive going off and just a few seconds later, another explosive going off. when we say we don't think at this time it was very sophisticated, that means plastic explosives wasn't involved, more like black powder