STEVE INSKEEP, HOST:
The thousands of people near the beach last night in Nice, France included David Coady. He is an Australian journalist. And like so many others, he was watching fireworks on France's Bastille Day - then this.
DAVID COADY: People started screaming and running. People were tripping over. We heard bangs behind us. And we didn't know at the time what they were. You know, fireworks had just been going off. I now know they were gunshots. So with each bang, the crowd became more panicked. And people were just trying to find shelter wherever they could, going into hotel lobbies, going into restaurants, just trying to get off the street.
INSKEEP: What we know is - more than 80 people were killed as a truck drove into the crowds and continued for more than a mile. What we don't know is who's responsible. Let's talk through the evidence we do have with Dan Byman. He's a counterterrorism expert at Georgetown University. Welcome back to the program, sir.
DAN BYMAN: Thank you for having me.
INSKEEP: OK. French police have said they found an ID on the man. We don't actually know if the ID matches the person. What evidence that you've heard is relevant to you?
BYMAN: We, of course, look for the background on the man himself. We're watching Islamic State social media and other sites for claims of responsibility. We're looking for known associates. So all these things together paint a picture of who did it and the broader forces behind them.
INSKEEP: You mention Islamic State - obvious possible suspect. You could also think about al-Qaida or other groups. Is there any reason to think it is Islamic State?
BYMAN: The Islamic State is the ascendant movement in France and in the broader jihadist community. So it's more likely. But at this point, anything is open. And it could be a broader sympathizer who feels affiliation with both groups.
INSKEEP: Let me ask about a difference between this attack and a couple of other attacks that struck Paris, France in the last year and a half. Those attacks in Paris seem to be coordinated - multiple gunmen, spectacular attacks. This, at least as far as we know so far, was one guy with a truck.
BYMAN: This seems like a even bloodier version of something Americans have seen in places like Orlando, where one person, enraged, has proven exceptionally lethal. I will say - the Islamic State and other groups have talked about ramming people and killing people with vehicles. So it's not completely out of the blue. But the scale of this is far beyond what you'd expect for that sort of attack.
INSKEEP: OK. You've said two valuable things there, I think. You said the Islamic State and other groups have proposed killing people with trucks in this fashion. So we don't know, certainly, that this is evidence that it's ISIS. It could be one of the other groups, as well.
BYMAN: That's quite possible. This sort of propaganda theme is out there, albeit not the most prevalent.
INSKEEP: And the second thing you've said that's valuable to keep in mind - and we don't have the full facts here. We're trying to just gather information as best we can. You mentioned the attacks in Orlando and elsewhere in the United States. Individuals who may have proclaimed some allegiance to a group but may not have had any real connection to them - that's what you're talking about there.
BYMAN: That's right. And that's something the Islamic State has pushed - and actually pushed much more in recent months - is trying to inspire wannabes and supporters to act on its own, even though the Islamic State doesn't have direct operational control.
INSKEEP: Let me ask about another thing because France is extending a state of emergency, as you know - state of emergency that was declared after the earlier attacks. It's raised many concerns about civil liberties in France. But my question for you as a security expert is this - has it done any good?
BYMAN: That's always tough to tell because you're looking for things that didn't happen. Part of it, to me, is a resource issue. France needs to make sure its police and security services have a lot of support. So the state of emergency helps with that. But in general, it's hard to stop attacks like the one we saw in Nice.
INSKEEP: What questions are still on your mind now, Dan Byman?
BYMAN: Big question to me is - who's behind this? And if so, was it top-down directed by the Islamic State or simply a sympathizer who acted on his own?
INSKEEP: OK. Dan Byman of Georgetown University - he is also, by the way, a senior fellow at The Brookings Institution. Thanks for joining us this morning.
BYMAN: Thank you. Transcript provided by NPR, Copyright NPR.