MS. DIANE REHMThanks for joining us. I'm Diane Rehm. President Obama visits Boston tomorrow to attend a memorial service in honor of the victims of Monday's bomb attacks. The investigation into who planted the two devices that killed three and wounded 176 is ongoing.

MS. DIANE REHMJoining me to talk about the attack and questions it raises about risk and security in the post-9/11 world: Dr. Alan Newman, associate professor of psychiatry at Georgetown University Medical Center, Gary LaFree, professor of criminology and criminal justice at the University of Maryland, and, joining us from a studio at NPR in New York City, Philip Mudd of the New America Foundation.

MS. DIANE REHMHe's a former counterterrorism expert at the FBI and the CIA. I do welcome your participation in this conversation. Give us a call, 800-433-8850. Send an email to drshow@wamu.org. Follow us on Facebook or send us a tweet. Good morning to all of you.

DR. ALAN NEWMANGood morning, Diane.

MR. PHILIP MUDDGood morning.

REHMPhilip Mudd, if I could start with you, I know they have reportedly found fragments of pressure cookers. They found pieces of mesh. What can you tell us about the investigation at this point?

MUDDWell, I didn't -- haven't seen that much new this morning. I think most Americans are probably looking for sort of a TV style resolution to this. But a lot of the work that has to be done right now is going to be drudgery in at least four big categories. The first is tips coming in on tip lines. We're already talking about thousands of people saying they might have seen something. The second, you're talking about at least hundreds or more witnesses, people at the scene who might have seen something.

MUDDThird, you're talking about interviews with the victims, obviously, and what they have seen. And also, you've got a lot of work to do at the crime scene, looking for materials, even tiny bits that might show you what kind of device was used, what kind of bag this device was in. So there's a lot of drudgery going on there, and, finally, to add to that, the 21st century phenomenon of video, video from local surveillance cameras or from smartphones.

REHMAnd so all of that would indicate a fairly strong effort not to jump to conclusions.

MUDDI think that's right. If we had clear signs of who this was, for example, if we had a claim that we took credibly, it might take you down a path quickly. But this doesn't look like a lot of what I chased during the past 25 years, that is, Islamic extremism that we saw hit America shores and that we witnessed in places like Madrid and London.

MUDDIt may be those guys, but again, it doesn't look like them. So you can't immediately assume it's those guys or it's the kinds of people that we've seen rise more commonly in recent years, that is, people like sovereign nation, sovereign citizen groups or white supremacist groups.

REHMNow, I understand we have seen the use of pressure cookers before. Isn't that right, Phil?

MUDDThat's correct.

REHMWhere?

MUDDI don't recollect the specific locations. I think what's notable here is what we're not seeing, and that is, if you wanted to immediately jump to a conclusion that this was a same kind of group that did, for example, London subway in 2005 or Madrid in 2006, you would have seen a couple of things that we did not see, that is an explosive device that was fundamentally different than the device we saw set into target that was in an enclosed space and represented the transportation, something like a subway or a plane.

MUDDAnd third, that target, I would argue, would have to be more iconic than this target for an international audience. For Americans, we understand what the Boston Marathon is. For an international audience, if you're trying to win recruits or gain funding overseas, I'm not sure the Boston Marathon gets you what the London subway does.

REHMGary LaFree.

PROF. GARY LAFREEYes. At the START Center, we have a database called the global terrorism database. It goes back to 1970. And before the show, we actually tracked pressure cooker bombs in the database, and we found a total of 30 attacks using pressure cooker bombs. The first one, interestingly enough, was in Madrid in 2001, and it was connected with the Basque separatist group, ETA. The largest number of them have actually been in Nepal to this point in time, and they have not produced a lot fatalities to this point in time.

PROF. GARY LAFREEIn fact, we could only identify two prior to the Boston case, all about 40 people wounded. The first attempted use of a pressure cooker bomb that we know about in the United States occurred in 2010. This was the one where the alert street vendor tipped police off to suspicious SUV parked in Times Square.

PROF. GARY LAFREEAnd inside the vehicle, the police discovered about 250 pounds of urea-based fertilizer packed into a metal pressure cooker, as well as, I think, a large number of M88 firecrackers. It's a little, you know, with 30 cases, little hard to predict longitudinal trends. But of the 30 cases, 13 of them are from 2012. So it does look like the use of pressure cooker bombers is definitely on the rise.

REHMBut for most of those cases outside of this country.

LAFREECorrect. Most -- over, well, half of them in the country of Nepal. The next most common was in Pakistan, then India, then we're down to just a couple of them in, well, one in Spain and one in the United States and two in Italy.

REHMI see. Alan Newman, in terms of the emotional reactions, what kind of level anxiety does a bomb placed at a marathon project?

NEWMANWell, the anxiety would be tremendous. I think one of the things that is probably the intent of the choice of a bomb is to terrify and frighten as many people as possible in addition to the physical injuries that are created by the bomb. And this is magnified even more by the fact that with YouTube and Skype and all the video that the effect of the bomb is transmitted instantaneously to the entire population.

NEWMANWe were all seeing the bomb explode, if not in real time, within minutes to hours, and so the effect on a population is tremendous because everyone actually sees the event as it's happening in people's responses.

REHMPhilip Mudd.

MUDDYou know, I remember being evacuated from the White House executive office building on Sept. 11 during the attacks, and I see a change in resilience. We're not a resilient country, by any stretch, compared to what I've seen from my counterparts in countries like Israel of Britain. But a couple of notable things, the first is, back then, people were saying, how could this happen here? And you're not necessarily hearing that. People understand that a country with a global footprint is at risk.

MUDDAnd second, as a personal level, I took the train up from Washington to New York yesterday and I was running on 6th Avenue at 5 a.m. this morning, I didn't sense any palpable fear. I didn't sense people saying, wow, I've got to honker down. There's a bit larger security presence but not significant for the train, so I take that, frankly, as a plus. We're not resilient, but we've taken at least a step to saying, hey, there's risk in this country. We've got to live with it.

REHMAlan.

NEWMANI agree completely. I was actually at the New Orleans Airport when I found out about this, and I was waiting for a flight back to D.C. And I know that in some previous disasters, the televisions would be turned on to something else. And the -- what I found, what's interesting was in the airport, all of the TVs were on news channels, and everybody in the airport is watching what's going on. And yet it didn't seem to trigger any kind of anxiety and panic about getting on a plane or related to airline safety.

REHMInteresting. Gary LaFree, this has been described as the second most lethal event since 9/11. But we are told that there've been a great many incidents prevented. What do you know about that?

LAFREEWell, our database, going back to 1970, tracks about 2,400 total attacks against the United States during this period of time. And, of course, 9/11 is, far and away, the most -- in fact, the most lethal in the world, the most lethal terrorist attack in our whole database. If you go -- you get a little bit different results if you go with total casualties where people are both killed and wounded versus total fatalities. If you look just at fatalities, the second most lethal attack against the United States was the Oklahoma City bombing in 1995.

LAFREEThen after that, there was a bombing at LaGuardia Airport in 1974 which had 11 dead. More recently, the Fort Hood attack, 13 dead. And then if you look at casualties, you get a somewhat different set of numbers. For example, the Atlanta Olympic bombing in 1996 had 111 casualties but only one death, the Amtrak rail sabotage in Arizona in 1995, 75 casualties, but again, only one dead. So this will rank as one of the more violent in terms of total casualties.

REHMAnd, Philip Mudd, I want to get to this question of the use of the word terror. Yesterday, we had a long discussion as to whether the White House was going to use it. Finally, President Obama did come out and use it. In your mind, what is it that constitutes an act of terror? When should that word be used? And doesn't it, to a certain extent, imply foreign involvement?

MUDDI don't think it implies for an involvement. For example, I would see Oklahoma City as an act of terror on U.S. soil by someone who is U.S.-born and raised. But I think the layman's definition would be the purposeful targeting of innocent civilians for a political end. I personally, having done this business for so long, don't like the word.

MUDDTerrorism in the eyes of the people who commit these acts is acceptable, especially in the Islamic groups I followed. When they can't go toe to toe with an adversary like the United States, they think it's perfectly legitimate to use these means. They cannot, however, defend against the word murder. And so I would prefer to get out of the terror business and get into the murder business. They killed people.

REHMInteresting.

MUDDThey did not have any end that is legitimate.

REHMGary LaFree.

LAFREEYeah, I think I'd agree with Phil's suggestion here. And actually, for the purposes of our database, we pretty much use the definition that Phil gave. So it has to be violence or the threat of violence by a non-government source and -- with a political motive. So we would include it.

REHMGary LaFree, professor of criminology, he is at the University of Maryland. Philip Mudd, he is former deputy director of the National Security Branch of the FBI. Alan Newman of Georgetown University Medical Center. Short break. Right back.

REHMAnd welcome back. We are continuing the discussion on the bombings in Boston at the end of the marathon on Monday. Here with me in the studio, Gary LaFree, he is professor of criminology and criminal justice director at the University of Maryland. Dr. Alan Newman, he is professor of psychiatry at Georgetown University Medical Center. And Philip Mudd is on the line with us from the NPR studios in New York City.

REHMHe is former deputy director Counterterrorist Center at the CIA and former deputy director of the National Security Branch at the FBI. I have a question from Steve in Birmingham for you, Phil, "Please ask Philip Mudd how effective community or group profiling of the type that you brought in at the FBI is at catching terrorists."

MUDDFirst of all, I don't buy that I brought in group profiling. What I brought in was an idea, I think he's referring to, called domain knowledge, that is, if you are looking in 2006, 2007 as a national security organization, which the FBI is, at a phenomenon like Somali extremism, should you be responsible not only for investigating crimes in your area of responsibility, in this case, Minneapolis would be a good example, or should you know who the community leaders? Should you have a relationship with them?

MUDDSo I'm not talking about going and spying in mosques. I'm talking about if you're a security organization, you cannot just react to what has happened. You have to think in this age of globalization about what's going on globally. In that case, unrest in Somalia, whether it has an impact in your community and whether you have enough of what we call domain knowledge to know who to talk to in your community.

REHMAnd here's an email from Bill in Winston-Salem, who says, "How often to bombings like this happen around the world with no one claiming responsibility? Does that possibly tell us anything about the bombers themselves?" Gary LaFree.

LAFREEOf the approximately 105,000 terrorist attacks that we've tracked back to 1970, globally, about 50 percent of those cases we never identify a suspect. The number is actually much lower in the United States. It's about 30 percent with no suspect identified. We are finding that there are big differences in attacks based on when someone claims responsibility.

LAFREEFor -- one of the more interesting ones is if people attack something like a mosque or a Christian church, a lot of times they don't identify themselves because the attack target makes it obvious what kind of organization they're with. On the other hand, when they attack, like, a chemical plant or transportation where it's not so obvious, they more often identify themselves. So...

REHMInteresting. And, Alan Newman, going back to that question of terror or murder, how do those words shape people's thinking about an event?

NEWMANWell, I think terror has definitely become a loaded word because it does have often different meanings. People often will perceive that it's international in origin. I think if you look at what we know about many bombers who have been apprehended and then studied, many of them do not see themselves as murderers.

NEWMANThat's not their identity. They feel that they are soldiers, that they are very justified in their actions. Timothy McVeigh, in the Oklahoma City bombing, although he reported that he might have chosen a different target if he had known that there were so many children, he felt that a certain amount of collateral damage was inevitable in the kind of actions that he was engaged in.

NEWMANAnd so I think that often times, the justification that the people that are engaged in these behaviors keeps them from seeing themselves as murderers. The -- it's unusual in the psychiatric world for us to attribute this behavior to somebody with a typical mental illness, but sometimes, we do see that. And they often also feel highly justified but not see themselves as murderers.

REHMAnd what about the rest of our population? Do you see or have you seen the incidents of PTSD, post-traumatic stress disorder, from or within an individual who wasn't there but who, perhaps, has seen these events unfold?

NEWMANThat's one of the aspects of post-traumatic stress disorder that has gone through a rethinking over the past few decades. When the psychiatric community first added post-traumatic stress disorder to our diagnostic manual in 1980, it was really seen in the context of people who had personally experienced some extraordinary trauma outside of the realm of normal human experience.

NEWMANSo people who were military, combat survivors, people who had been raped or kept in concentration camps. As time has gone by, we've realized that many people who simply observe something happening to someone else, who experience it through some other way may develop the symptoms of post-traumatic stress disorder, and sometimes it's hard to predict. You often have people who experience a tremendous trauma but yet have a good recovery.

NEWMANThe actual long term -- people who develop post-traumatic stress disorder are a minority of those that are traumatized. After a year, maybe somewhere between 10 and 20 percent will have post-traumatic stress symptoms. Most people will actually recover pretty well. But you'll have other circumstances where somebody has what appears to be a minor trauma or even having post-traumatic stress symptoms. After 9/11, people reported complaints of PTSD...

REHMExactly.

NEWMAN...who were living in Montana and other places in Middle America. So there's a certain vulnerability that some people have to the symptoms, and you don't necessarily have to experience the trauma directly.

REHMAnd, Phil, that gets back to the whole question of resilience. And to what extent this has become a resilient nation because of what we've seen?

MUDDI hesitate to answer this 'cause I don't think the answer is going to be that welcome. But we talk about resiliency, we do not practice it. And as a practitioner, for example, I was called down to testify in front of the Congress or brief the Congress on the 2005 attacks in London before my counterparts in London were called before parliament. I'm guessing that within -- and I've already heard this in some of the public airwaves -- within days, people will start to say, what went wrong in this case?

MUDDAnd my answer is going to be, if you want to – we'd not live in the land of the secure. We live in the land of the free and the home of the brave. And if you want to live that way, you have to accept risk. So to close, we say we accept risk, but then when we face it eye to eye, we don't really have the capability to handle it when it's new. We handle it on murders. We handle it in drug trafficking organizations, and bluntly, we handle in child pornography, which we seem not to focus that much on. But in this new phenomenon, we are not resilient.

REHMTell me what your thinking is if it should be discovered that the attackers were foreign as opposed to domestic.

MUDDMy thinking is that we ought to sit back and acknowledge one simple fact. Back when I was sitting at the threat table from about 2003 to 2005 when things were really intense at CIA -- we met every night -- I thought we were losing. We saw attacks in Kenya, Saudi Arabia, Indonesia, and I thought the revolution of al-Qaida had metastasized beyond the point that we could contain it.

MUDDToday, indisputably, not only are we winning but the group of al-Qaida is almost destroyed and the revolution is in the midst of being shattered. We ought to step back and say this is not an indication that we should change that judgment. And furthermore, if we overreact to this, we pretend that an adversary that is now three-feet tall is 10-feet tall, and that's exactly what they want. So we shouldn't step into their game.

REHMBut suppose it turns out that it is al-Qaida or an affiliated group.

MUDDI would say we have the tools now that we didn't have 10, 12 years ago to go against al-Qaida or its affiliates, and that is to eliminate leadership through incredibly lethal and effective operations and to work with partners who are also getting better at that. I wouldn't say we step off the gas pedal in terms of executing those operations. I would just say we ought to sweep up the glass and not talk about it.

MUDDIf we do talk about it, we ought to put it in the context of murder and not call them what they want to be called. They want to be called terrorists. They can't explain. And Zawahiri, the second-in-charge of al-Qaida, has publicly tried to explain why they kill innocents. He can't do it. So we ought not to focus too much on it, and we ought to, if we have to talk about it, simply put them in the context of murder.

REHMGary.

LAFREEI totally agree with what Phil is saying, but I was a little surprised. When we actually looked at our 2011 data and we take the 20 groups that were most prone to attacks during 2011, we count 12 of those are al-Qaida affiliates, groups like Boko Haram, al-Shabab and others, which actually -- so it is true that al-Qaida's central is very much in the sidelines, but a lot of al-Qaida affiliates are actually pretty active throughout the world.

REHMAll right. I'm going to open the phones now, 800-433-8850, first to Frank in Baltimore, Md. Frank, you're on the air.

FRANKGood morning. Thanks for taking my call.

REHMCertainly.

FRANKI have a question for especially the psychiatrist and the psychologist about the delivery of mental health services and the problem associated with "professional distance," which means most people who have any inclination to get into this behavior would never even bump up against someone who is anywhere near the mental health system. My suggestion is that they consider -- and going back to your -- what you do understand around domain knowledge.

FRANKI mean, I think that's a critical step in the right direction. To somehow employ or engage therapists who live in the community, who have bonding directly in a given community and who are in a position not to necessarily spy on anybody, but bump into people who have, you know, questionable -- have questionable ideas of...

REHMAll right. Alan.

NEWMANIt's a great question. One of the things that comes up with many of these cases is, is there a way that the mental health field can prevent these events from happening from identification? And it's extraordinarily difficult. When you look at -- certainly if you look at the various small handful of bombers who have been later diagnosed with a mental illness, these were almost always people that were completely averse to the idea that they actually had any psychiatric problem.

NEWMANSo Ted Kaczynski, the Unabomber, was later diagnosed with paranoid schizophrenia, but he was absolutely resistant to the idea even though his motivation for sending the bombs was tied to his delusional thinking. In the 1940s and '50s in New York, there was a man known as the Mad Bomber, George Metesky, and he was later found not guilty by reason of insanity. But these are extraordinarily rare.

NEWMANOne of the problems that I think we have in the mental health field is that if you look at the broader issue of dangerous people -- this has come up with the Virginia Tech shootings and with many of the mass shootings, the shooting in Colorado -- one of the problems is that the tools that we possess to identify people at high risk are not as sophisticated as we like. We'd get too many people if we use them.

REHMAnd you're listening to "The Diane Rehm Show." Philip Mudd.

MUDDLet me just back up what was just said, and that is Americans tend to extrapolate when they see an event like Virginia Tech or that shooting at Fort Hood a few years ago. They take a single event and say, if I piece together the three or four pieces of information that were available, you should have seen it. They look through, in hindsight, a perfect kaleidoscope. I would suggest that rather extrapolating, they try to analyze.

MUDDWe might have been able to find somebody like Nidal Hasan or the Virginia Tech shooter, but there's going to be another thousand or 10,000 people who come into the sites as false positives, and they fail to understand what happens not only in terms of investigative resources in the budget, but also what happens to American values. If you start backwards and say, we'll start with 100,000 people, boil it down to 10,000 and start investigating, 99.9 percent are going to be honest, hard-working Americans, and we've just put them in an investigative net. It's just not that easy.

REHMAnd easy is the question that so many people are concerned about. How difficult is it going to be to find the perpetrator or perpetrators, Phil, of this heinous act?

MUDDThat, to me, is more a function of time than a function of certitude. This person or persons, I believe, will be found over time if you measure time in terms of months or even years. The likelihood to me with this level of investigative effort that we don't know over some period of time, again, might be measured in years. If you remember the anthrax attacks in 2001, again, a major investigative effort, but it took us a long time. So I would say high likelihood that these people will be or this person will be identified. Not certitude, though. It's not 100 percent.

REHMAnd to you, Gary LaFree. Do I understand correctly that an envelope containing a very suspicious substance, Ricin, was sent to a member of Congress today?

LAFREEThis just happened, I guess breaking news today, that's absolutely right, and has been confirmed as indeed being Ricin.

REHMNow, would you see that in any way connected to what happened in Boston?

LAFREEI certainly wouldn't at this point in time. However, the Boston case, on its own, is what we refer to as a coordinated attack. So, in other words, more than one attack that's timed to go off in close proximity and close time. And interestingly, of, you know, the 100,000 or so attacks we've looked at, about 12 percent of them have been these sort of coordinated attacks, where there's more than one related incident, like the 9/11 attacks.

LAFREEAnd interestingly also, these have become more common in the United States than the rest of the world since 9/11. There's a higher proportion of these coordinated attacks in the U.S.

REHMAnd, Phil, the London Marathon is due to take place this Sunday. As a specialist, what would you be advising London Police?

MUDDThey have been dealing with these problems from the Irish era more than we have. So when I was at the bureau, my view is we can learn a lot more from them than they can from us. I would be advising them on a tactical level, but not on a strategic level. It'd be like a child talking to an adult in some ways. And the tactical level will be quite simply every hour I'm telling them what's going on in the investigation. And obviously if we find any leads in the U.K. or Europe, I'd be talking to them. But there's not much we can teach the Brits. They are the best in the business.

REHMAnd this is wide open.

LAFREEWe actually tracked -- we were interested from the database of how common these attacks on marathons were, and we actually found seven of them in the database. The most recent one -- the first one we can find was back in 1994. It took place in Bahrain. But it's interesting that Phil mentions our colleagues in the U.K. because three of them happened related to Northern Ireland. Four of them have happened since 2003. So they seem to be on the uprise.

REHMGary LaFree of the University of Maryland. We'll take a short break here. Your calls, your email, when we come back.

REHMAnd as we talk about the aftermath of the acts of terror in Boston that occurred at the marathon on Monday, here's an email from Bernadette in Laconia, N.H., "Why is it that public school systems continue to keep the statistics of children who are in need of serious therapy a deep dark secret? When are we going to realize the sooner this population is helped through the mental health system, the better it will be for all concerned?" Alan.

NEWMANI think one of the challenges, and this gets back to what we were talking about a few minutes ago, is what's referred to as hindsight bias, that when somebody commits a criminal act and then you look at their lives, you see a tremendous number of warning signs and clues that make us think why wasn't more done. Part of the problem, though, is that if you follow a population over time, that has a lot of risk factors.

NEWMANIdentifying on the front end which one of those people is going to actually engage in a tremendously violent act is extremely hard to do. And if you try to do things like civilly commit to a psychiatric hospital, all the people that are a high risk, you might be hospitalizing a hundred people or more for each person that might have done something.

NEWMANAnd then, of course, you can't prove it because if they were detained, you won't know. So even though there are a lot of children where you look back in hindsight and was obvious that they were at risk, there's so many that we forget about who showed tremendous risk but yet did not engage in anything near that's dangerous.

REHMGary LaFree.

LAFREEYeah. I was just going to come back to something that actually Phil said earlier about differences in civil liberties and resilience in the United States. I was at a conference yesterday at the United Nations involving a guy from the home office in the U.K. He was talking about that they'll have some perhaps very controversial or incendiary speaker at a university in England, and we just said well, we'd go in and cancel the talk.

LAFREEAnd I think the Americans in the audience were kind of -- the idea that the government would come in and cancel a university lecture just was appalling to the Americans. So I think there's also, you know, our willingness to go in and label people and to publicly pronounce them as having these sorts of mental problems as, you know, we have a pretty high bar for doing that in the United States.

REHMAll right. To Wilton, N.H. Good morning, Ruth.

RUTHI'm delighted you can talk to me on such a busy day. I am really proud of us that we are essentially back to normal today. Runners in Manhattan are maybe fewer in number, but they're out there. I don't know anything about terrorism, but I think that the main objective of -- I think the main objective of terrorism is fear. And we're not afraid of them. They can bite us, and they can make us nervous. But we will annihilate them.

REHMAll right. I'm going to follow that with an email from Dave in Mason, Ohio, who says, "One of your commentators presented the idea that we Americans talk about being resilient but are not. I totally agree. We talk a good game but do not perform that way. I think part of the reason is we're so TV-oriented. We see major crime solved in 37 minutes -- "CEI," (sic) "NCIS", "Law and Order" or the infamous "24" -- instant solutions to extremely complex events." Phil.

MUDDThe first is we've -- the Brits, for example, have dealt with terrorism, and it's not that they accept it, but their resiliency, compared to ours, is the same ballpark. On the other hand, if there are few knifings in London -- I was in London a couple of years ago when there was a spate of knifings -- that is national news for -- I'm not talking about murders. I'm just talking about knifings, not even killings. In this country, we'll probably, I'm going to guess, have this year 12, 14,000 murders.

MUDDSo we're resilient in areas where we have an esoteric understanding of the problem and accept it, which I find odd. We're not resilient in areas that are new and random. The second thing I'd say that I find curious, as a former person who both paid taxes and spent a lot of taxpayer money, is that we don't want to pay taxes.

MUDDPeople don't know it here, but we're relative low taxed compared to the rest of the world, especially Europe. But when we think about the explosion and expectations for the government, that we should not only protect America offshore but that we should protect an American in a shopping mall, people have a vastly greater belief in what the government can do to protect them than their tax dollars pay for.

REHMBut then, Phil, if you argue that we are less than resilient, what do you mean? Where does that leave us in terms of our outlook, our thinking about ourselves, our thinking about the entire country?

MUDDAs a practitioner, I don't necessarily think this is bad. I'm a glass half-full kind of guy despite all the years of watching kids who wanted to blow themselves up. And I look at the debates we have today and I look at the experience I had in government in every night watching a new threat come into the threat matrix, and there was always a threat, whether or not Americans knew about it.

MUDDAnd I'm kind of happy that we succeeded in what we did enough to give people space to both almost forget about what happened in their day-to-day lives and to get on with real life. So I look at the lack of the resiliency and say, as an optimist, I don't necessarily like it in terms of being an American. I wish people would just move on. But as a practitioner, I'm sort of proud that we gave him the space to be less resilient than other people are around the world.

REHMAlan.

NEWMANYeah, I think that, to get back to what Phil was saying a minute ago, the cost of doing more is something that I think the average person is not aware of. The -- in addition to the civil liberties issues of hospitalizing, providing in-patient psychiatric treatment, the cost that are involved are extraordinary. If you look in Washington, D.C. in the early 1970s and before, you might have 7,000 people hospitalized at St. Elizabeth's Hospital, whereas now the number is less than 300.

NEWMANSo the -- So people have an expectation that things get done, but the cost of doing what a lot of people ask for are simply prohibitive, I think, for the world we want to live in.

REHMPhil.

MUDDLet's do a reality check here to play off each other. People who watch TV shows, I suspect, believe that the FBI and others have thousands or tens of thousands of people under surveillance. Let me tell you something and take you into the real world: surveillance means three teams, 24/7. They've got to rotate off because you're going to recognize someone, if you're the subject, after a couple of days. You've got to be up on their automobile, their workplace, their car, their friends.

MUDDYou got to be listening to their phone calls, watching the emails and text. If it's foreign language, you've got to have surveillance. If they travel, you got to coordinate with foreign services. People think this is a surveillance society or that we can do more. Let's me tell you, we can't do that much because the money it would cost to do what people think we do would be outrageous.

RUTHSo do you think we're going to have to rely on luck to find out who did this, Phil?

MUDDNo, I don't think so. I think it's going to be a combination of classic investigative work and a break. I mean, a lot of these cases rely on breaks, and a break to me is somebody making a mistake we can exploit. Somebody says something wrong in a bar, we do a sweep in a house that we think is vaguely suspicious and realize there is a pair of wire cutters that look like the same kind of wire cutters that would've built a device, so you make your own luck. It's not to say that breaks aren't critical. In fact, they are extremely important in investigation. But you make your won luck.

REHMAll right. Let's go to Moultrie, Ga. Hi there, Frank. You're on the air.

FRANKYes. Thank you for taking my call, Diane.

REHMSure.

FRANKI enjoy your show.

REHMThank you.

FRANKWe were watching the news yesterday, and it's really just bewildering for everybody, like, who would be so angry to bomb people at a Boston Marathon? I mean, it's ridiculous to think who would have the motivation to do that. And then I remembered -- it just dawned on me that there were so many people at the New York City Marathon that were so angry, fighting mad about the situation because they were trying to have a -- the New York City Marathon in the wake of a big storm.

FRANKAnd there were people that were so upset. They were fighting mad about, well, let's run it. And then there were people that said, no, let's don't run it. And then when they had all this equipment there for the New York City Marathon, people got mad because they weren't using it to help the people who were trying to survive and recover from the storm.

REHMAnd then Mayor Bloomberg ultimately cancelled the marathon.

FRANKExactly. And there's people out there that are probably still so fighting mad about that, they might do something like this, who knows? But, I mean, there's some crazy people out there. But...

REHMWell, I'm not sure that that kind of anger is going to translate into, as everyone at this table has said, acts of murder, at least I sure hope not. Let's go to Grand Rapids, Mich. Hi, Steven.

STEVENHello.

REHMHi. You're on the air.

STEVENHi. Yeah. My question was for, I believe, the man from the FBI who had stated to change the definition of terrorism to the definition of murder. And his specifics words were any non-governmental organization. And my question is, why can't governments be included as terrorist organizations in a way? Not to say that every government would be, but what I mean is, why couldn't a government carry out what we would call maybe a terrorist -- or terrorist act, if it is murder? For example, (unintelligible).

REHMAll right. You're breaking up on us, Steven. Phil, I think you got the gist.

MUDDThe simple answer is we can and do declare governments for -- as terrorist states for having committed acts of terrorism. The government of Iran, for example, has long been involved in supporting Hezbollah in terrorist operations, including bombings in South America. What I was talking about in distinguishing terror from murder was not on the definitional aspect. There is a technical U.S. government definition for terrorism. It was more of how we corner the adversary.

MUDDWhen this adversary talks about its acts, it talks about justifications for acts that are understood within their own environment. But one reason that terrorism is dying around the world -- or al-Qaida core is dying is they killed too many innocents. So people who are with them on 9/12 and said we like bin Laden were killed in Saudi Arabia, in Jordan, in Iraq. And so those who thought bin Laden was OK 12 years ago are now saying, you can kill the Americans, but don't kill us. They don't accept murder in their own countries, and al-Qaida can't explain why they do that.

REHMGary.

MUDDSo we ought to take them up on what they're most vulnerable for, and that's being called murderers and not terrorists. It's not definitional issue. It's just an optics issue.

LAFREEAnd just responding to the caller, the reason we exclude non-governmental or government cases is because it's just a whole another ball game. And it's actually even harder to get non-classified information on. So we are -- we're very, you know, given that our plan is to try to measure this phenomenon the best way we can, it's important for us to keep a very consistent definition over time but not to say that the issue you're bringing up is not extremely important as well.

REHMAnd to Norman, Okla. Hi there, Dave.

DAVEHello. I just want to bring up a point. I've listened to all what's happened in Boston and what's going on. Matter of fact, my daughter was in the med tent working that day. But we're here in Oklahoma, and we're getting ready to have our bombing memorial marathon here in about a week, Saturday. And I'm thinking about what a statement that would be, you know, when you connect it with Oklahoma City bombing? And, I mean, here, they're talking about keep doing the same thing as they always have done. You know, they have the bomb-sniffing dogs and all that but...

REHMSure. Can you ever protect people when you're running a marathon?

LAFREEWell, I guess the good news in this business, if there is any, is that you get a lot fewer attacks than you can imagine. I mean, as the caller just done, I mean, people can imagine all sorts of horrible ways that you can do damage. Unfortunately, the vast majority of those never happened.

REHMAnd you're listening to "The Diane Rehm Show." Phil, what would be your guess as to where the investigation goes from here?

MUDDMy guess is that it's going to take some time to sort through the massive volumes of data from interviews, talking to witnesses from the site, from tips that are coming in and from the massive video in the crime scene investigation that we will get. And that I think we might not expect to see results of this for quite some period of time.

MUDDI'd kind of put this in two baskets: either it's going to be resolved relatively quickly or we're going to have to sort through these big volumes. And that might take many months. So it's either one end of the spectrum or the other, I think. I'm not certain about that, but that'd be a guess.

REHMGary, do you agree?

LAFREEOh, that seems very reasonable. And I could mention, in fact, that your viewers maybe surprised that...

REHMListeners.

LAFREEListeners may be surprised -- thank you -- that terrorist attacks we've been tracking in the United States are actually way down. And they're especially down since 9/11. So, I mean, there are many reasons for that perhaps, but perhaps at least part of that is law enforcement and the job that the FBI and other agencies are doing.

REHMAnd you've been keeping track of those. You've got statistics?

LAFREEWe do. And, in fact, your listeners could get those statistics for themselves directly by going to our website, which is at start.umd.edu/gtd, and all of this is unclassified work.

REHMAnd we will link that to our own website, drshow.org. And, Alan, where do you think it's going from here?

NEWMANAs far as the...

REHMInvestigation.

NEWMAN...investigation, well, I'll tell you that what probably won't be helpful will be some kind of profiling. One of the things that we've learned is trying to divine the characteristics of a bomber from the behavior is -- has not been very successful. Most of the cases that I'm familiar with, it was police work and investigation and sometimes a tip.

NEWMANAnd even though there's cases where people talked about how the profile of the person that they captured matches them so greatly, a lot of times that involves hindsight bias. They -- it doesn't actually often lead to the capture of the person. So I think, based on history, that this case is going to be solved. We'll learn a lot about whoever is responsible when that day comes, but I don't think we'll be able to solve the case by making predictions about their psychological makeup.

REHMSo what you're all saying is we've got to -- the FBI, the CIA, everybody has got to be involve to a certain extent looking for the smallest clues, the smallest links that might take us to a source.

LAFREEAnd along those lines, a couple of projects that we worked on recently where we've looked at foiled plots and how they unraveled in failed plots, the thing that really struck me about them is most of them, 90 percent of them I would say, were solved by a pretty much typical police procedures. It wasn't -- as we're hearing from Alan, it wasn't profiling necessarily, it wasn't putting, you know, these complicated databases together.

REHMGary LaFree, he's professor of criminology and criminal justice at the University of Maryland, Dr. Alan Newman, associate professor of psychiatry at the Georgetown University Medical Center and Philip Mudd, former deputy director of the Counterterrorist Center at CIA, former deputy director of National Security Branch at the FBI. Thank you all so much.

LAFREEThank you, Diane.

NEWMANThank you.

REHMAnd thanks for listening, all. I'm Diane Rehm.