kennedy assassination. >> now, leiter -- i'm calling you leiter because both of you are named michael. the fact that we are hearing now that the fbi and others are asking for pictures and videos, i understand about the nylon bags. but the fact that we know that this bomb, how it was made, i'm a new yorker. is that not the same way the bomb in the times square attempted bombing was made? wasn't it the same type of bomb? and does that tell us anything about the same type of people may be behind it or it doesn't mean anything? >> i don't think it means that much. it was the same kind of bomb as in times square. and that attack was sponsored by the pakistani taliban. >> okay. >> two reasons that's not that important. first of all, the pakistani taliban has already said they didn't do this. if they have, i think they would have taken credit for it. second, that was an exception for how groups like the pakistani taliban and al qaeda normally build bombs. >> oh, it was an exception? >> that's not what they've used in the past. >> okay. >> so i don't think that's a tactic they would be likely

nbc news terrorism expert michael leiter is with us. michael, are you surprised the investigation is moving as quickly as it is? >> not really. it was funny, when i was asked questions about this four hours ago, we didn't have a lead, and people said, why isn't it moving faster. these pieces come into play. there is a lot going on behind the scenes and each small piece can lead to a big opening. identifying that these bombs were potentially in black backpacks or bags, it is a huge lead. you know what you are looking for. with so many people working on this and so much on since 9/11, i'm not particularly surprised. >> the counterterrorism chief said there is two basic ways these investigations go down. they get solved within the first few days or or months later or never. is that your experience. >> it does vary. there is often an early break. someone will take responsibility or you will have that video shot and it is easy to go. certainly if the case goes cold for only a couple of days, couple of weeks, it might be hard to pick that bac

it was something, as it's being called, radicalized. >> important to you, mike leiter? >> i think very important. a lot of people think this is an atypical story, of people who have lived here for a long time, become radicalized, and it regrettably isn't. in the times square bombing we had a case where someone had lived here for 13 years, had an mba, had worked for an american company, and then tried to bomb times square. the challenge here, david, there are lots and lots of people who go through these crises and become more radicalized, but very, very few of them actually become mobilized and become terrorists and that's an incredibly hard piece for the fbi and others. >> and you're speaking, mike chertoff, did the fbi miss something? they were on him, tamerlan, that is. they talked to him. they tracked his digital footprint. chairman rogers talking about him then traveling on an alias, which i had not heard before. so the red flag is up, but then they close the books on him. after they took a look at him, they determined there was no threat here. >> i think that is go

michaelle leiter was the counter terrorism director under president george w.bush. >> you can't protect all of the people at all of the large sporting events or any public gathering. that's the advantage terrorists have. they can look for the softest, least defended area. >> it is not unusual to see trash bins removed, mailboxes removed, even the manhole covers screwed down. that's the kind of extraordinary security you get in a presidential zone. putting in place that kind of security at an outdoor marathon, brian, would be a different matter. >> again, how ironic this happened at what was perhaps the most secure zone in all of boston along those 26 miles today. tom costello from washington tonight. tom, thanks. >>> we'll take another break. when we come back, an eyewitness to today's bombing. [ male announcer ] this is kevin. to prove to you that aleve is the better choice for him, he's agreed to give it up. that's today? [ male announcer ] we'll be with him all day as he goes back to taking tylenol. i was okay, but after lunch my knee started to hurt again.

michael leiter is an nbc news national security analyst. he's the former director of the national counterterrorism center in washington. michael, thanks for joining us. where i'm sitting is about four blocks from the crime scene. but on a area about a block away is being treated as a crime scene. i'm sure investigators have been working into the night and will be working around the clock. what are the first things they're looking for, michael? >> good morning, chris. they're going to do a number of things simultaneously. as you referenced, right around the scene, they're going to secure a fairly wide area. they have to get as much evidence as they can from the actual bomb blast. that's important to understand the type of explosives that were used, how they were detonated. and then, that can be compared against past similar explosions. to try to determine who is responsible. second, they're going to be talking to enormous number of people in the area. what did they see in they're going to be collecting videotape. and all that will be combine

michael leiter is former direction of the national counterterrorism center.ete, this morning we've heard a lot about this individual who was questioned overnight and then his home was searched. we heard michael isikoff mention that it's actually two saudis that have been investigated, but this doesn't appear to be -- >> they were the two that were in his apartment. right. >> there doesn't appear to be much to this, right? spl well, it's too soon to know. there have been some conflicting accounts about what he was doing right before and right after the bombing. he was seen running from the scene. well, of course a lot of people were. but he had severe burns. apparently his clothing was on fire. and that means that he was obviously standing very close to one of the devices. so that makes him suspicious in the minds of some people. he's been questioned. one official told me this morning -- i said could it turn out that he was just an innocent bystander and the official said, yes, it could. but nonetheless, just to show how thorough this investigation is, they go

and none of them will be true. >> michael leiter from d.c.s for that perspective. >> thanks a lot. >>> just after the break, reaction to monday's bombings has spread well beyond our borders and created a heightened sense of alert around the globe. when we return, we'll look at that. hey! did you know that honey nut cheerios has oats that can help lower cholesterol? and it tastes good? sure does! wow. it's the honey, it makes it taste so... well, would you look at the time... what's the rush? be happy. be healthy. into brand-new apartments... before rooftops were transformed into electrical generators... before an abandoned lot in brooklyn could become a vibrant neighborhood... and before hannah seliem could close her very first door to her very first bedroom... an architect, a developer, and our commercial banker, met over lunch and shared a vision. that's the power of connecting an idea to a community. that's bank of america. it's not for colds. it's not for pain. it's just for sleep. because sleep is a beautiful thing™. ♪ zzzquil™. the non-

if michael leiter can still hear us in washington -- are you with us? >> i am, brian. >> i have been saying all day as long as we keep the balance more good guys than bad we'll be all right. the other lesson is about law enforcement, trails people leave behind. the leaps and bounds technology has taken. we have said many times in the past couple of days. following oklahoma city we were in rough shape in terms of the ability to investigate this type of thing. now the sweep of technology. it's hard to get away with something bad in this country. >> it is. this is a silver lining on a dark cloud going back to 1996 with oklahoma city, 1998 with kenya and tanzania, the first world trade center bombing through 9/11. what the last 12 years have given us is incredible human capital. incredible talent within organizations like the fbi and cia. incredible coordination between the federal government and state and local governments. what we have seen today wouldn't have happened in 2000. and the technology to pull it together. five years ago it could have occurred

michael leiter is our nbc news counterterrorism analyst. you received from your sources a caution today that this perhaps was running on ahead of itself. and this can have a bad effect on an investigation. >> absolutely. with all the media reporting about the possible arrests, they are very worried about the person or people being spooked and they are nervous about expectations at this point. for a while people were saying it's not going fast enough. now people expect an arrest in the near hours and the fact is knowing the person it can still take some time. >> now about the evidence. we have a big haystack here. so far we have found some of the needles down to the zipper pull on what could have been the bag and the wires and the battery. we also have imagery -- tons of it -- and that has to be a big early help. >> that is invaluable. it's something even three or four years ago we wouldn't have had. all of that imagery from the stores, the police and people, you combine that with the forensic evidence and the secret intelligence we are not

we're going to turn now to nbc's michael leiter. he's a terrorism analyst. he's joining us now from washington, d.c. michael, just from what we've heard as it unfolded all night long, complete chaos still in some areas, especially in watertown, massachusetts, where a suspect is still at large and clearly extremely dangerous. but the latest information about the suspects, what does that tell you? >> well, it tells me that honestly these guys probably don't lack the sophistication that people started imagining when we were just talking about the pressure cooker bomb. it was very, very simple and not much to it. they had obviously planned a lot out. i think that's how the fbi and boston authorities had been approaching this. although they now thought they recognized two, who knows how dangerous they could be, what else they could have set up, improvised explosive devices on their body they were carrying. this shows these two had thought a lot about this for a long time. we saw some of that planning with the precise placing of the bombs right there at the finish

nbc analyst michael leiter was director of the national counterterrorism center and clint van zandt is a profiler. all of this is a key related, battery pack, circuit board, news about the pressure cooker. a piece of it discovered. so much physical evidence and then the picture taken by the video surveillance camera at lord & ta are lo, we've confirmed, it's a picture of someone putting down a black bag, some sort of shopping bag, and then walking away from the bomb site. >> well, it's been a very good day, chris, and it's interesting as we started this before the information came out, the refrain we're hearing is why do we know so little at this point and the fact is, as we've said over and over, it takes time. now, what you just described is two legs or three-legged stool. you've got the forensic evidence from the blast site. that's helping them understand the bomb and how it was made. potentially you can trace things there. the secon leg of that stool is the photographic evidence and videotape which is just invaluable and then the third leg of that stool, which thankfully is not bei

used in the boston bombings, joining me now, nbc news justin correspondent pete williams and michael leiter. pete, ha have you learn about the bombs themselves? >> well, what we're told by authorities, andrea, is that they're crudely made. they appear to have been assembled inside a pressure cooker. it may be some of our younger viewers don't know what that is, but in the olden days when you wanted to make something tender, you put it in this pot with a tight lid on it. and the steam wouldn't escape and you could build up pressure and things cook faster in them. the premicrowave days. inside a pot like this, a pressure cooker is assembled the device. it includes a low-power explosive. something like black or smokeless powder, gun powder, if you will. not a high explosive like dynamite or a plastic explosive or the common tatp, which seems to be the one of voice of terrorists when they build bombs, terror bombs overseas. so it's crudely made, it's set off they believe by some kind of electronic timer. it's carried to the scene, they believe, in some kind of back pack and then just set down b

let's go to michael leiter. i'm well beyond my ability in talking about this but tell me where i'm right or wrong. he said it was clearly outside but he think it is came from the trash cans. >> it's possible. it's really hard to tell, chris. we've seen over and over today, this started about 2:50. i would say about half of what we hear is right and half of what we hear later on is wrong. we heard that there was a bomb at the jfk library. >> exactly. >> we have to take this slowly and the president was right about that. it's going to be a methodical investigation. could they have been in the trash can? it's certainly a possibility. were they timed to go off later and potentially hurt first responders, we're not sure yet. >> what does it tell you that the people lost legs and limbs, going horizontally, the blast. >> it suggests that the blast was close to those people and across the ground rather than something higher up. that's self-explanatory. shrapnel may have been included. what this shows, at least, is these

joining us now to help us understand what this means is michael leiter.s an nbc news national security analyst. mr. leiter, thank you for joining us. >> good to be here, rachel. >> we know the letters contained some amount of ricin. they do not know the potency of it. how significant does that seem to you? >> honestly, until we get the final results probably tomorrow morning, i would still not read much into it. these were tested twice in the field, first the automatic detector was set off, the field test was set off. that shows an element there and anybody can get them and be matched up. the lab tests show whether the caster beams in the match have been processed so it is actually the protein, the toxic protein, of ricin. and you have to figure out how much ricin there is, how potent it is. that is still inconclusive. until we get to tomorrow morning, we can't say whether or not there's ricin there versus elements of caster beans. >> i know from reading enough about it, they are what you make ricin out of, i know it's something considered to be one of th

let me start with michael leiter. the other day, it seems like a year ago, two, three days ago you, had this sense, professional instinct, if you will, that this killer, one of the two bombers, was a local. tell me how you came to that assessment. >> well, chris, my take -- >> he is a local. >> he is a local and he's got deep ties to boston. and my take was there's no doubt that the boston marathon is a worldwide known event, but unlike many of the targets, a lot of people really have used in the past, there's something specific to boston about it. there's something specific about the finish line and about patriots day and my take from that was that this is someone who knew the city, knew the region, knew what would be most terrorizing to boston. >> knew the heart of the city. >> absolutely. >> knew to hit the heart. clint van zandt, your sense now of where are we going? this has become sort of like the friday night bronco chase, if you will, in a very wide metaphor there. here we are in a chase of a person. this guy,

deserve answers. >> joining me now from washington, d.c., congressman patrick meehan and michael leiterrmer director of the national counterterrorism center. congressman, there's heavy security in boston and major cities across the country, including here in new york city. what are the challenges of the national security forces and the first 24 hours following what we saw in boston? >> that's a recognition that you might have some copycat or follow-up events and there's already plans in place that are implemented. i think they're in as a precaution and no indication that i'm aware of any of further activities that people believe they be on the horizon. >> michael, let me ask you how crucial is it during this investigation now that the fbi, the police are asking for the thousands of witnesses who are on the scene there to look over what they have and provide them with photos, with images that might be useful? >> it's absolutely critical. there's a lot of video that they'll get from the store owners and from the city of boston and in today's age of smartphones, iphones and the like, there

joining me is michael leiter. want to talk to you about what's happening in boston.lowing up on what chairman royce was saying. we don't have the dots all connected and i was told by several officials last night and again today, that they are very aware of what happened ten years ago. on wmd. we're not going to go without really hard evidence. but the real key here is the russians. with all due respect, it's not the qataris and with whom they're arming, it's that the russians are blocking a ground investigation by the u.n., by not supporting us in going in on the ground. >> i don't think it's just the russians, i think it's appropriate cautionings, having worked on the commission that investigated the intelligence failure on wmd in iraq, i'm extremely sim thympathetic to t idea that intelligence is often imperfect. it's easier to know if weapons were used than to know if it is to know if weapons are hidden. in that sense we probably have a better sense. there is obviously pressure building. british, french, israelis, all intelligence services with whom we work very,

joining me now michael leiter director of the national counterterrorism center.el, always good to see you. good morning. >> good morning, chris. >> we were having the conversation with pete williams about the older brother and we know in 2001 at the request of the foreign government, we think russia, but we don't know for sure, the fbi calls tamerlan and asks him some questions, and doesn't find anything. how does that work? because armchair quarterbacking is pretty easy to do and i have this vision of a guy or woman sitting in a room and he has this parade of people coming in who they got to call on from somebody, a foreign government or an informant or something. tell us how that works. >> and just to clarify one piece, it was actually 2011, not 2001 that they got that tip. >> yes, 2011. sorry. >> fundamentally the fbi and state and local officials do get a sea of tips which say, you know, my neighbor this or worry about that guy. and what they'll do is they'll open a threat assessment. all this information will generally go in the joint terrorism task force wh

. >> michael leiter in our washington bureau. thank you, as always. across town we go to the white house. chuck todd was in the briefing room when the president entered about 6:10 p.m. tonight to give his remarks on what the white house was comfortable saying so far. chuck. >> reporter: i can tell you this, brian. one of the things the president did not say is he did not call this terrorism. this is, i can tell you from talking to sources, this was discussed and the decision was made not to have the president use that specific word. a national security official does e-mail and says this, to clarify, any event with multiple explosive devices, as this appears to be, is clearly an act of terror and will be approached as an act of terror. however, we do not know yet who carried out this attack and a thorough investigation will have to determine whether it was planned and carried out by a terrorist group, foreign or domestic. so they're being very careful with their language. we know the president has been briefed all day from the fbi director. now his hom

let's bring in michael leiter of, an nbc news terrorism expert. good afternoon, mike. what do you make of these possible connections between the two brothers and chechnyan terrorists? >> what we really know their ethnic is chechen. the one brother has traveled to chechnya. we really, really can't go down the road yet of assuming, even assessing is likely, that they were, in fact, linked to chechen group such as the islamic jihad union, iju. that really is premature. i think probably more likely at this point is the older brother might possibly at least have seen something in the relationship between chechnya and russia, the struggling chechnya, that drove him in a direction of extremism. that's more likely. but i would say the direct connection too early to say. >> because up to this point, chechen independence movements, chechen terrorists have been concerned about the location, the geography, of their own nation. that didn't previously involve the united states of america. >> that's absolutely right, and i think that's another reason why a direct connection from a ch

michael leiter, former director of national counterterrorism center. good to have you here. thank you, sir. >> thank you, rachel. >> i want to tell you the fbi has set up a phone number for anybody to call with information on today's attack. they are describing their call for tips in terms of people who may know anything about what happened in boston today. in terms of no information being too insignificant. no potential lead being too small. if you do have information that you think might be of help in the investigation into what happened today in boston, the number to call is easy to remember. it's 1-800-call-fbi. 1-800-call-fbi. which translates to 1-800-225-5324. all right. we are live at mass general hospital in boston. stay with us here on msnbc. we'll be right back. [ coughs ] [ angry gibberish ] [ justin ] mulligan sir. mulligan. take a mulligan. i took something for my sinuses, but i still have this cough. [ male announcer ] truth is, a lot of sinus products don't treat cough. they don't? [ male announcer ] nope, but alka seltzer plus severe sinus does it treats you

michael leiter, many thanks for your keen insights.reciate that. >> thanks very much. >>> while the city of boston was completely shut down following the intense manhunt for suspect number two, let's go to boston and nbc's catty tur. pretty unprecedented, right? you and i were talking at several points yesterday and it was rather incredulous just the ghost town environment of boston. >> you really couldn't believe it. certainly an eerie sight, alex. yesterday the streets of boston should have been teeming with commuters. there should have been tourists. there should have been people outside enjoying the weather. but instead they were hunkered down. they were staying inside, heeding orders that there was a terrorist, potentially on the loose. about 1 million people ordered to stay inside. to lock their doors. boston and its surrounding suburbs were virtually under siege. a lockdown in the suburbs, a shelter in place order for the city. >> we're asking people to shelter in place. in other words to stay indoors with their doors locked, an

new york city, nbc news capitol hill correspondent luke russert, and misterrorism expert michael leiter, and bob herbert, a distinguished senior fellow at dimos. >>> let's go to kristin welker for more. >> reporter: alex, good afternoon. here's what we know at this hour. this letter was received yesterday at an off-site mail facility. i want to emphasize that. it did not get close to the white house. it's typical for letters sent to this facility to undergo a screening. during that process, it was discovered that a letter addressed to president obama did contain a suspicious substance action as you mentioned, similar to the letter that was sent to senator wicker. so right now secret service is working in concert with the fbi, with the capitol police, to determine exactly who sent this letter why and what the motive is. we are expecting press secretary jay carney to deliver his daily briefing. i want to make sure this is very clear. this was a scheduled briefing for 11:45, so we expect him to come out at any minute. he will undoubtedly get a number of questions about this situation, abou

. >> let me bring in michael leiter. michael, what are your sources telling you? >> well, be honest, i don't always check with folks during this critical time. folks may not like that. but this is a fluid situation. what i would tell you from my experience in the white house is there is a lot of information flying around right now. it is quite clear to me that investigation has accelerated. that people who are of interest have been identified. whether or not that's led it arrest, this is where information always falls apart. i expect over the coming hours, we will have more come out from the fbi. my guess is a combination of cell phones tracking, forensics from the bomb, video from the site. all of that will become the additive whole that indeed an individual or individuals of interest at least, have been identified, and some may be brought into custody. >> and we know that, michael, the fbi is the lead investigative body, if you will. they are collecting all of the evidence. to the point that pete made, a senior official says under is no rest. no person even iden

. >>> joining us now in new york, michael leiter, an nbc news terrorism expert and former director of the national counterterrorism center. with us from boston, kevin cullen, columnist with "the boston globe." michael, you and i were just talking about, just with the volume of forensic evidence, how are they making decisions about what leads to pursue and sort of what to do with all this evidence? >> yes. there's a huge amount of physical evidence, digital media. that's the videotape and the like. and there's, of course, all the intelligence that we're not hearing about and we shouldn't hear about. the clandestinely collected human intelligence, signals intelligence. phone calls, e ma-mails and the like. what you have is a large joint terrorism task force in boston that is kind of collecting a lot of this. back in washington you have fundamentally every bit of the federal government, department of homeland security, fbi, putting hundreds if not thousands of people on this. prioritizing that is a really key element. at the very beginning, they're going to pursue almost everything that

>> first of all, michael leiter, that is one of the terrific under reported stories thus far.rauma teams at these world class hospitals all of them, five or six of them, within four or five-minute ambulance ride of the blast site. that is a hugely underreported story and god bless them for everything they did. the question that i have for you is the progress of the investigation. i was speaking to several people yesterday involved in the investigation. maybe you can flush this out a bit. it seems that they are quite confident in the direction that they are headed and what they have received so far. if you want to liken it to a murder scene, is it not accurate to say that they have kind of a partial fingerprint here in the sense that they have a piece of a pressure cooker, they have remnants of a bag, they have the outlines, the ingredients of the bomb, so i would think that that would be a huge step down this progress road, would it not be? >> i think it is. the analogy to a fingerprint is good although it's a little imperfect and because a fingerprint is distinct to one indiv

. >> michael leiter thank you for your time and expertise. >>> despite the many news conferences and updates, there's more questions than answers about what happened yesterday. we'll go live to boston and talk with one of the eye witnesses to the bombings, coming up next on "now." welcome to the new new york state, where cutting taxes for families and businesses is our business. we've reduced taxes and lowered costs to save businesses more than two billion dollars to grow jobs, cut middle class income taxes to the lowest rate in sixty years, and we're creating tax free zones for business startups. the new new york is working creating tens of thousands of new businesses, and we're just getting started. to grow or start your business visit thenewny.com departure. hertz gold plus rewards also offers ereturn-- our fastest way to return your car. just note your mileage and zap ! you're outta there ! we'll e-mail your receipt in a flash, too. it's just another way you'll be traveling at the speed of hertz. introducing chase liquid. card hassles? the reloadable card that's easy to activate

a sophisticated triggering mechanism, michael leiter telling us of lesser importance in narrowing down suspect in terms of expertise and training but more important to give clues to trace to the source to find out how the bomb was assembled and where the pieces came from that allowed the bomber to put

a sophisticated triggering mechanism, michael leiter telling us of lesser importance in narrowing down the suspect in terms of expertise and training but more important to give clues to trace to the source to find out how the bomb was assembled and where the pieces came from that allowed the bomber to put it together. keep it here at msnbc. obviously the story is developing tonight. we'll keep you posted. now it's time for "the last word" with lawrence o'donnell. stay with us. >>> tonight, we are live in boston with new pictures of the moment the carnage began and new clues in the investigation and new stories of the heart break of those killed, including the 8-year-old boy happily growing up on the same streets where i grew up. >> no claims of responsibility. the range of suspects and motives remain wide open. >> who was behind twin bombings? >> someone knows who did this. >> grieve for our neighbors. >> taken to six hospitals. >> three people dead, more than 176 injured. that 8-year-old boy is martin richard. >> 8-year-old martin richard is among those killed. >> 29-year-old krystle

a sophisticated triggering mechanism, michael leiter telling us may be of lesser importance in narrowing terms of expertise and training but more important to give clues to trace to the source to find out how the bomb was assembled and where the pieces came from that allowed the bomber to put it together. keep it here at msnbc. obviously the story is developing tonight. we'll keep you posted. now it's time for "the last word" with lawrence o'donnell. stay with us.

i wanted to bring in mike at leiter in as well. from your assessment and your sources, how is this proceeding, the fbi 2,000 tips, getting pictures, putting together the pieces of what these bombs were, what they were made of, how far have they gotten, do you know? >> i think they're doing quite well. we're not yet 48 hours in. we're getting there now, and they now have a pretty good idea about these devices. they know how many, they have a sense of how they were carried to the side, so that's a huge piece. from surveillance cameras that were in place from the city of boston, businesses in the area, and of course all of the photos and surveillance movies that people got on that you are iphones and everything else. there's been an enormous amount of work. with the central be gens agencies, they're seeing if they can -- or human intelligence to point in the direction. all of those things are think over the coming days and weeks will sloely by correlated. i think if things go well, they could -- in the come days. >> pete williams, is

mike at leiter will join us to discuss. plus behind the explosion of home-grown extremist groups.k about a new report on so-called patriot groups. >>> in the aftermath of boston, what is the future for reform efforts on guns and immigration. luke russert and bob herbert join the panel. all that and more, coming up next. and do you know your... blood type? a or b positive?? have you eaten today? i had some lebanese food for lunch. i love the lebanese. i... i'm not sure. enough of the formalities... lets get started shall we? jimmy how happy are folks who save hundreds of dollars switching to geico? happier than dracula volunteering at a blood drive. we have cookies... get happy. get geico. fifteen minutes could save you fifteen percent or more. to prove to you that aleve is the better choice for him, he's agreed to give it up. that's today? [ male announcer ] we'll be with him all day as he goes back to taking tylenol. i was okay, but after lunch my knee started to hurt again. and now i've got to take more pills. ♪ yup. another pill stop. can i get my aleve back yet? ♪ for my pain,

. >> michael leiter, thank you so much. been with us throughout this. thank you so much.ime at the white house, president obama this morning will be briefed on the latest developments bybi director robert mueller and other senior members of his team. white house official says the boston bombings appear to be an act of terror. although the president stopped short of calling the attack terrorism. now, house homeland security committee chairman michael mccall had this to say. >> we still do not know who did this or why. and people shouldn't jump to conclusions before we have all the facts. but make no mistake, we will get to the bottom of this. and we will find out who did this, we'll find out why they did this. >> simultaneous bombing, mass casualties, spectacular event. all the briefings we ever get on a potential terrorist attack, all the ingredients that are in there and we saw that, unfortunately, yesterday which led me to call this an act of terrorism. >> let's bring in matt visor, "boston globe" white house correspondent. i was thinking listening to the president last

michael leiter, counterterrorism, cyber security, national annist for us. served as the director of national counterterrorism center from '08 to july of 2011. was in the room during the bin laden raid. michael, you've been watching and listening to the coverage. give us an expert's eye view. what do you think we have here and what would you be looking for? >> well, the first thing i would say, brian, is at this point, kind of an hour into the event, we still have to accept that the information is going to be incredibly fragmentary and a lot of it's going to be wrong. all of the boston city police department, the federal government, mostly the fbi, the department of homeland security, the white house, everyone is now scrambling to understand what exactly happened in that location. and away from boston, people are starting to put in place some of the preventative security measures that chuck todd just mentioned at the white house. so i expect that we'll start to see some additional police presence in cities like new york, los angeles, chicago. my initial take

. >> we have nbc national security analyst michael leiter with us this morning from washington. michael, this is an incredible law enforcement effort that we have seen overnight and into this morning. door-to-door searches in the town of watertown. a military conqoi of 15 military vehicles by one count from our sources there on the ground. was does this tell you with all of the people locked inside their homes? >> this tells me we haven't seen anything like this since 9/11. the scale of shutting down whole communities. it also says that unsurprisingly officials are taking this so seriously. especially when you've now found one of the perpetrators with an ied on his body. they have to move incredibly carefully because they are going to expect to see other ieds and improvised explosive devices and boobytraps everywhere they go. >> think where they live and an area they have a new type of crime scene if they were so armed along the way of this route from this chase yesterday. >> authorities say they believe these are the same two that committed the marathon bombings on monday so wh

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