>> there are sources that we've had that have told us that there are at least two other bombs that weren't detonated as well. so you can look at the brighter side of it, say, it could have been worse without the medical hospitals that we have so clear. without the triaging that's there for the marathon anyway. it's small solace to those people that have lost their loved ones and, you know, the people that have been injured. but this could have been worse. >> as a former d.a., though, one of the things that occurs to me about having unexploded devices in custody is that's very valuable evidence in terms of tracking the types of devices these were. and in terms of giving you leads for investigative -- >> it is. >> -- process. >> the devices that have exploded, they're very valuable, too, in terms of evidence. so that kind of forensic evidence, we're bringing the best people in the country to boston. we have some of the best to