AILSA CHANG, HOST:
OK, let's bring in someone who has been a part of past explosives investigations. David Chipman was a special agent for the Bureau of Alcohol, Tobacco, Firearms and Explosives. He was there for a quarter of a century. Welcome to the program, David.
DAVID CHIPMAN: Thanks for having me on your show.
CHANG: So what do you look for in the first several hours of an investigation like this?
CHIPMAN: Well, this investigation is a bit different because I would say it's ongoing. These were mailed. There could be other devices in the mail, multiple locations. So this is unique in that fashion. And I would say it's ongoing. So people are working hard just to make sure the communities are safe and that we don't relax too soon.
CHANG: Now, the recipients of these packages have an apparent ideology or a party affiliation in common. All of the targets are Democrats, people who could be described as left-leaning. How much will that fact drive the investigation, you think?
CHIPMAN: At this point, I don't think much at all. I know when we arrived at Oklahoma City...
CHANG: Yeah.
CHIPMAN: ...And I was recovering the remains of Americans from that scene, I wasn't making some calculus that Republicans or Democrats had been killed. This is an attack on our country, our institutions and an attack on the media. And I think that that's how investigators are viewing it. This is game day. They've trained for this their whole career. And they will solve this case. I don't know how long it will take. But this is a big deal. And we're just grateful that no one has been injured to date. And there's a mountain of evidence because these devices did not go off.
CHANG: But in trying to figure out the motivation behind these attacks, you say that the party affiliation of the targets wouldn't be relevant at this point.
CHIPMAN: Clearly it's worthy of speculation. All I'm saying is when I arrived at the Oklahoma City scene, it was two years earlier that I was working at the World Trade Center bombing. In the back of my mind, I just assumed that this was a foreign terrorist attack that blew up the Oklahoma City Federal Building. It turned out it was not.
CHANG: Right.
CHIPMAN: It was a fellow American. So I think that what you'll find is that the professionals are just looking at the evidence. They want to link the bombs together. They want to see how it was delivered. They want to develop clues. And I'm not saying that they're not blocking out the clear linkage in the - you know, the politics of the targets.
CHANG: Right, right, right.
CHIPMAN: But at this point, they've got all this evidence. Usually a bomb goes off, and you don't have all these clues.
CHANG: How else might investigators try to establish whether these devices are linked? We know that they arrived in different locations along the East Coast.
CHIPMAN: Yeah, so every bomber makes things a certain way. You know, it - you could see the same components being used, sometimes their tool marks. Sometimes there'll be fire - fibers in there. Sometimes you might even get DNA or a fingerprint. You know, it looks like in some of the photos I've seen on the Internet that the address was printed out. And the FBI will be able to compare those to see if a similar device was used. So I feel confident that they'll be able to link these devices. But then the real work will be, can you link it back to a person or persons unknown? And I know they're really looking at how were these delivered.
CHANG: And the fact that none of these devices actually exploded - that fact does help investigators - right? - when the devices are still intact and might still retain fingerprints, for example.
CHIPMAN: Absolutely. And that's why the first responders are taking so much time to render these devices safe without destroying the evidence. It's not like they're going to put another explosive device next to it and blow it to smithereens. They have techniques used to preserve evidence. This will be important as the investigation unfolds. But right now there are devices that could be in the mail not yet delivered. We saw this in central Texas recently where devices were going over time.
CHANG: All right, that's David Chipman, former special agent for the Bureau of Alcohol, Tobacco, Firearms and Explosives. Thank you very much for coming in today. Transcript provided by NPR, Copyright NPR.
