and i think all those runners who were in the race in the boston marathon and runners in other road races around the world now moving forward, i think many of them are going to take that same attitude and i think that's really what you have to do primarily. stay moving and really concentrate on that over which you have -- >> frank shorter, an inspiring message for all of us. thank you for your time. it is a day where we all as a nation can come together and decide to not let the terrorists infiltrate our brains as frank shorter just spoke. now i'll hand over the show to my colleague wolf blitzer right here on the same street corner in boston. >> thanks very much. let's hope that actually happens. we want to welcome our viewers in the united states and around the world. i'm wolf blitzer reporting today from boston. you're in "the situation room." once again this nation is facing terror and tragedy.

here are the latest developments in the horrific bombings which brought a bloody end to the boston marathon. the investigation has yielded major new clues. sources now say the explosive devices were apparently made from pressure cookers hidden in backpacks and set off by timers. the death toll stands at three. we've now learned the name of another person who was killed, krystle campbell, a young woman at the finish line to cheer on the runners. the other known victims included 8-year-old martin richard, whose mother and sister were badly wounded. the third person was killed but that name still hasn't been released. we do know a lot more tonight about what -- about the wounded, about their injuries, 183 people were hurt in the bombings. almost two dozen of them critically, at least nine of the wounded are children. we're expecting a news conference any moment now. we will of course bring it to you live with all of the latest

information. let's focus now on the bombs that turned that finish line into a scene of carnage and chaos. john king is standing by here with us. you've been doing some reporting all day, john. what's going on? what is the very latest as far as the investigation is concerned? >> it's interesting, wolf. 26 plus hours later. now many more questions, many more questions than answers. authorities primarily are trying to review every piece of forensic evidence gathered from the scene just a few blocks away looking at every piece of video footage they can get from surveillance cameras, looking at all the debris that has been collected. at this moment as you know, they are saying there were just two explosive devices they believe. they believe they were small, compact devices put into metal canisters, probably pressure cookers. and then filled with nails, filled with other metal pellets and powerful explosives. the pellets and nails were kwha caused the carnage. they believe just the two. yesterday they were talking about other suspicious packages. they believe now some of those were detonated. they were just suspicious packages in the wake of the investigation. perhaps an over reaction in some

case but every precaution taken. what else from there? this is a tactic these pressure cookers that has been used in the past by al qaeda, used by the taliban. but it is also a technology sadly you can find on the internet and i'm being told by several officials, some of the other correspondents as well, that there is zero, zero evidence as yet any intelligence evidence of any international or foreign terrorist involvement, so they're obviously thinking about that, investigating that. but there is no evidence of that as yet. at the moment i'm told there is a frantic, that is the word used by a boston police source review of all the video evidence and everything else trying to come in. as of just a couple hours ago in a conversation with the boston police source i was told as of yet in that review nothing, no evidence yet. nothing on the video review so far that shows any suspicious people arriving at a scene seeming to put something down and going away. that is what they're looking for right now. and so you have this just frantic investigation and as time passes experts in this tell you, you know, if somebody left

a clear signature, often you get that within 24 hours or so. that is the nervousness you find among state and local officials working with federal authorities that they're desperate for answers here, at the moment mostly questions. >> no one has claimed any responsibility domestically, internationally, any place. >> right. that is also a signature of international terrorist groups who need to claim responsibility to get the attention in their view to get the credit sadly for something like this. that has not happened yet. again that is a factor in the investigation as they try to sort domestic or international. >> stand by for a moment. joe johns is also working the pressure cooker part of these bombs. joe, what are you learning? >> wolf, a law enforcement official told me today that authorities are preparing for a long and slow investigation here and it starts with pieces of the explosive devices scattered along an enormous crime scene. even before the dust started to settle, authorities were asking what kind of explosive device

created this. the picture of the bombs now starting to emerge is that they were deadly but crude. a federal law enforcement official with knowledge of the boston bomb investigation tells cnn the bombs were hidden in bags inside a metal pressure cooker. a law enforcement source also told cnn that it's likely but not certain that a timing device was used to detonate the bomb. emergency room doctors said they believed the bombs contained bbs and nails intended by the bomber to kill or maim as many people as possible. >> there were a variety of sharp objects that we found in their bodies, probably this bomb had multiple metallic fragments in them and we removed them. >> mike bouchard is a former top official with the bureau of alcohol, tobacco, and firearms. >> it could be a relatively simple device but that's all you need.

whatever they did this was an anti-personnel device and accomplished the mission. you don't have to have a high tech. you don't have to use high explosive, military explosives. >> reporter: the pressure cooker bomb is not new. plans for this kind of thing are on the internet making tracing the bomb style to a specific group or individual more difficult. the failed terrorist who tried to blow up times square in 2010 tried a variation on the idea but it didn't work. and pressure cooker style bombs are a common form of ied used in both afghanistan and iraq made famous by this english language article in an al qaeda terrorist magazine known as "inspire." >> this doesn't necessarily mean that this is jihadist, al qaeda inspired. but it's striking nonetheless that there are some close parallels between the description of the devices in boston and this recipe in al qaeda's "inspire" magazine.

>> reporter: the homeland security department has warned in the past about the dangers of pressure cooker bombs. important also to say that authorities have not told us if they have figured out whether the bombings were the result of international terrorism or if this was a home grown attack. wolf? >> so, clearly, this investigation is at an early stage when i'm hearing you say, joe, that they don't really have any har evidence or any evidence at all this could have been internationally inspired. they really don't have a whole lot of evidence domestically, either. is that what i'm hearing? >> i've asked a law enforcement official on the ground there in boston about whether they just simply have nothing. that official would not comment on that. nonetheless, they are telling me they expect this to be a very long slog. so i take that to mean they're not expecting to pick up anybody tonight. >> so far -- let's go to the

news conference right now. the mayor of boston is speaking. >> -- following comments and announcements with respect to the recovery and then any of us are available to take questions. let me start with special agent deloria. >> thank you very much, governor patrick. good afternoon. i'm the special agent in charge of the fbi's boston division. let me recap our investigative efforts this afternoon. yesterday at this time our collaborative efforts were focused on saving lives and treating the injured. at the same time resources were directed to ensure the safety of our community. as soon as those important tasks were completed, first responders focused on establishing a criminal investigation. the fbi's boston joint terrorism task force composed of more than 30 federal state and local law enforcement agencies including the boston police, massachusetts state police, atf, hsi, united

states secret service, and others, responded to the scene. many of them were already there as part of the general security for the marathon already in place. the first step law enforcement took was to secure the physical area around the blast for the purpose of preserving evidence in the area related to the devices, itself. this morning the fbi along with boston pd, massachusetts state police, and atf, officially began its forensic evidence recovery effort at the site. their goal was to recover physical items related to the blast. those items have been recovered and are being sent to the fbi's laboratory in quantico, virginia. they are specialized examiners and will reconstruct the device or devices and determine its makeup and components. among items partially recovered are pieces of black nylon, which could be from a backpack, and what appear to be fragments of bbs and nails, possibly contained in a pressure cooker device. we are expediting this blast

evidence to our laboratory in quantico, virginia for a complete and thorough analysis. in addition, this morning it was determined that both of the explosives were placed in a dark colored nylon bag or backpack. the bag would have been heavy because of the components believed to be in it. at this point it is difficult to determine specific components used until we can eliminate other factors which may have already been present in the environment. in fact, we won't know with some certainty until the laboratory completes its final review. away from the scene yesterday afternoon, the jttf began its investigation. immediately after the bombing the fbi initiated a command post that was assigned to the jttf. intelligent analyst and analysts and personnel from every agency associated with jttf and many others on their own including boston pd and mass state police, more than 1,000 law enforcement officers across many agencies

had been assigned to this investigation via the command post. they began canvasing sources, reviewing government and public source data bases, and conducting interviews with eyewitnesses and others to determine who is responsible for this crime. we are doing this methodically, carefully, yet with a sense of urgency. all across the nation and around the world, the force of the united states is working hard to locate those responsible. already the fbi has received more than 2,000 tips as of noon today. many of which have already been reviewed, analyzed, and vetted. we will continue to work around the clock tirelessly, side by side with our partners to continue to investigate and act on these leads. regarding who might be suspected of this event, the investigation is in its infancy. as law enforcement it is our responsibility to thoroughly review each and every piece of evidence. some of our activity you may see. some of it you won't.

but rest assured we are working hard to get the answers. at this time there are no claims of responsibility. the range of suspects and motives remains wide open. importantly, the person who did this is someone's friend, neighbor, co-worker, or relative. we are asking anyone who may have heard someone speak about the marathon or the date of april 15th in any way that indicated that he or she may target the event to call us. someone knows who did this. cooperation from the community will play a crucial role in this investigation. we ask that businesses review and preserve video surveillance, video, and other business records in original form. we are asking the public to remain alert and alert us of the following activity -- any individual who expressed a desire to target the marathon, suspicious interest in researching how to create explosive devices, the noise of

explosions in remote areas prior to yesterday which may have been used as tests by those responsible for the acts. someone appearing to be carrying an unusually heavy dark bag yesterday around the time of the blasts and in the vicinity of the blasts. as further substancive details become available that are appropriate for release together we will either issue a press release or hold a press conference. tomorrow we plan to hold another press conference in the early afternoon. thank you very much. i want to thank the public for their tremendous support in this investigation. it is crucial to our ultimate success and i thank the residents of the city of boston, citizens of commonwealth of massachusetts for this information that has been provided to us. i also want to thank the western hotel here for their services in allowing us to use their facility. we are very grateful for that. thank you very much. >> thank you, rick. mr. mayor? thank you, governor. thank you all for being here

once again this afternoon. as the investigation continues and more victims have been identified, in true boston fashion, we are receiving many offers of help and assistance. just earlier today, senator warren and i visited several of the victims of the tragedy. your heart goes out to them and their families during this very difficult time for them. i also want to talk about the police, the fire, e.m.s., all of those services. the volunteers who reacted quickly during this time of tragedy, also. because of the outpouring of help, we've set up an organization, one fund boston, which is to collect money to help people who might need help during this time. the website is one fund boston.org. and if you go to that site and donate any resource you have some of the folks have stepped

up so far like john hancock, john carney, larry lekino, and the boston foundation, all there willing to help. that's how boston has come together like never before. we're all here because this tragedy is not going to stop boston. we are boston. we are one community. we will not let terror take us over. >> thank you very much, mr. mayor. thanks to all of the donors, the inaugural donors if you will for the one fund boston and those who will contribute. in the nature of contributions, the lieutenant governor and i visited a couple hospitals this afternoon as well and one of the things that we had an opportunity to do is thank the extraordinary medical teams who have responded to the needs of people who were hurt. one of the things we learned is that there is a need for blood on a sustained basis.

so this will be -- i just want to make sure everybody understands this the way i think i understand it. do not go and make a donation today but next week and the week after that there will be an ongoing need for blood donations. so, members of the public who are following these announcements who are inclined and able to make blood donations at their local hospital or through their red cross, next week and the week after that are medical professionals anticipate a need. we are going to have an interfaith service. it will be at 11:00 on thursday morning. it'll be held at the cathedral of the holy cross in the south end. i'm very pleased that the president will join us for that to help us all heal. another point that i wanted to make before i open it up to questions, you've heard special agent deloreaux and many others in law enforcement tell you what

we can about the ongoing investigation and the fact that there is not yet an identified suspect. these are times when all kinds of forces sometimes conspire to make people start to think of categories of people in sometimes uncharitable ways. this community will recover and will heal if we turn to each other rather than on each other. one of the things that we'll emphasize at the interfaith service, and that we want to emphasize by our example every day is that we are one community as the mayor said. we are all in this together and the sensitivity we show to each other as we heal will be an important part of how we heal. now we're happy to take your questions. >> we'll interrupt the governor. this is patty campbell the mother of krystle campbell, and this is in medford. krystle campbell was killed yesterday here in boston.

let's listen to the mother. >> she was a wonderful person. and everybody that knew her loved her. she loved her dogs. she was always smiling from -- couldn't ask for a better daughter. i can't believe this is happening. she was such a hard worker in everything she did. just doesn't make any sense. couldn't ask for a better daughter. thank you, guys. >> thank you for respecting our privacy. >> very moving words from the mother of krystle campbell the young woman killed yesterday one of three killed here in boston. very, very moving words from patty campbell. let's go to the other news

conference. the police commissioner is speaking. with the finish line this year, and assigned more offices down in that area. if you look at the videotapes you can see that. we'll have a lot of times to vette all these plans and determine exactly what happened but this is an integral part of the ongoing investigation. >> did something go wrong with your plan? >> well, this is a soft target. anybody can go into a church to do this type of thing. when you have an event you can't lock it down like it is a military operation. it needs to be open to the public, commerce occurring up and down that parade route. by virtue of the type of event this is it requires we don't turn these events into a police state. so we struck what we believed to be the appropriate balance. we'll review all that and come

to some conclusions down the road. this is our priority right now. >> are you suggesting that that situation is in fact -- >> no, we haven't actually had any complaints, but, the u.s. attorney and i were talking earlier about those concerns and just wanting to remind people this is the time to show that sensitivity. >> what specifically can you tell us about? >> i believe i said pressure cooker. possibly a pressure cooker. black nylon bags, possibly at both sites. yes. black nylon bags as opposed to i think you said residue.

i can't characterize the specifics of that. we are postulating they needed to be heavy bags to carry the devices. >> does it appear they were twin bombs? the damage the same in both, the fragments the same in both? >> i think that would be speculation right now before the evidentiary review is complete. the evidentiary review is still ongoing and i wouldn't want to speculate or characterize any more than i already have. >> how uncommon is it -- >> there are a variety of reasons why. this is a very complicated investigation. it is going to be pursued

methodically, carefully, diligently but with a sense of urgency. we are barely 24 hours on into this investigation and so i would say it is still in the early stages and that is the best way i can characterize that. >> has the senior state ever issued -- [ inaudible ] -- as they were building their properties on boyleston street will you encourage them to do so with reinforcement glass? >> one question per customer. you know that, right? >> i don't frankly know the answer to the question except that guidance folks along the route get in preparation for a specific event. in terms of how we go forward

i'd like to remind everyone we've had 116 years of incident free marathons and every year we have learned from the last experience. this is a painful and tragic lesson but we will learn from this as well. next year's marathon will be even bigger and better. >> how many people go through that area, the ballpark range of how many people? >> i don't know the answer to that. do you? >> we do not -- >> you're talking about the area where the blast occurred in particular? >> yes. >> we don't make specific estimates on crowds but tens of thousands of people are right at the finish line and in this group of people extends off and on for 26.2 miles. >> how much close are we? >> there's been a lot of work done. they are going over the crime

sce scene. a lot of the evidence is coming from analysis of video. it is very early in the investigation as was said quite clearly, this has to be a methodical investigation. it's not a rush to any particular end. we have to be very cautious >> especially -- knowing what you know about the devices now are these things bomb-sniffing dogs could find. >> i couldn't speculate on that right now. again, we're still in the process as commissioner david just mentioned still in the process of going through the evidentiary review at the crime scene. that process is not completed yet. it is ongoing and i wouldn't want to speculate or characterize that anymore until that process is complete. >> do you know anyone who was hurt and have you spoken to the families of those who were killed? >> i visited several families

this afternoon at the brigham young hospital. they were very strong. the families needed help. a young woman i saw there who lost her legs had a lot of courage and i think they're hanging in there. we're offering all the help we can, both at the medical but also the city help and we'll be there further. the families are going through difficult times and we as a city and individuals have to support them the best we can. >> did you know any of the families? >> i did. i did. >> anything you want to say about -- >> no. >> you guys want a lot of answers. some of these things are personal things. you get down to something like that it's very personal and you don't get into facts of conversations with victims personally. >> you said earlier that you paid special attention to --

[ question inaudible ] >> as the governor said, we review each one of these events and at the end of our review last year we determined the crowds were larger than usual and so we put extra offices at the event especially toward the end of the race and especially when the runners were first coming in. but as i said, if you review the pictures and the videotape, there was a significant amount of police presence there. the officers are lining the route looking into the crowd which is what their job is. as i said, we talked to our federal and state partners. there was no specific threat about this event. this was a similar threat picture after 9/11. we're certainly very vigilant but there was nothing specific about this tick yar event. we had teams of undercover

officers working the crowd at the end of the race which is standard procedure because of pick pockets that occur in that area. those teams were out there fully deployed as were our eod dogs which were in the area all through the race. >> boston college i believe organized 8,000 people to walk the last 5 years of t-- miles oe marathon route. are you aware of that? >> no. >> does law enforcement know anything about that? >> no. >> there is mention of circuitry or a circuit board kind of device that was found. can you say anything about that? i'm assuming -- is that something you want to share with the store owners? >> i believe the circuit board was brought up by a member of the media right here and my

remarks on that, i'm not prepared to speak to that, any aspect pertaining to that right now. certainly, going out to the community conducting the logical investigation i can assure you that the joint terrorism task force is doing that as we speak. >> are there any communications as to whether it took a lot of planning to do this, that they may have been planning for many years? >> again, hopefully that will come out in the investigation. that would be speculation on my part right now to speculate how much planning went into this. i do not want to provide you with anything that might be inaccurate information ultimately. i wouldn't want to speculate on that. >> the names of two victims have come out. >> commissioner davis advises me that there is not enough work

done right now to make a notification to the next of kin for the third victim. >> given that you're discussing pressure cookers what is the sophistication of that? is this something made in a basement? >> i think pressure cookers, we're familiar with those as relatively ordinary cooking devices historically going back several years. as far as precisely what evidence was found at what location, i wouldn't want to go into details of that right now. there are multiple pieces of evidence that are at the crime scene as you might well imagine from the serious, tragic nature of this event. i wouldn't want to provide you with inaccurate information right now as to what specific information was found at both crime scenes. information that could possibly be a pressure cooker was found at the site and we are putting

that out to the public in an attempt to generate any lead information. >> when will the national guard be gone? when they're not needed anymore. the job of the national guard right now is to secure the crime scene. the work of going through the crime scene continues. we're not going to rush that. that will involve some inconvenience to people but i can't tell you when that work will be finished. the other thing the national guard is doing is helping with the random bag checks and that'll continue for the next day or so anyhow. >> we had a tremendous out pouring of support from the public in terms of video that has been submitted to us. it has been tremendous.

we are analyzing that right now, taking a look at it. we are bringing specialists up in quantico to assist us who are digital, video analysis experts. we are bringing the best possible resource thas the fbi can bring to bear to boston to participate in that aspect of this investigation. >> can you describe what you get from the public? >> it's various video submissions of the area around the crime scenes that were taken around the time of the blast both before and afterwards. all the video like this we encourage the public and particularly business owners in that area to continue to submit this information. this is very, very important and we thank the citizens of boston and the commonwealth of massachusetts for submitting this information. >> can we hear from the atf about the, what the potential explosive that might be?

many say there was evidence of gun powder. >> that is correct. that type of smell has been reported but we aren't prepared to go into the specifics as to the blast scene. it's a fairly expansive, large scene and we're having to be so methodical in our processing it. we do know there has been some debris nearby on the roof tops and embedded in some of the buildings nearby. that gives you kind of a scope of the power of the blast and you can see how it was so devastating. >> white smoke or just gun powder? >> we're not prepared to get that specific yet. >> i want to ask a favor on behalf of somebody i met this afternoon. the lieutenant governor and i were over at tufts medical center and visited a number of

victims but one young woman named victoria who is a northeastern student who is in the hospital because of a serious shrapnel wound she had in her leg in the -- around the site of the first blast. she was scared. she was carried i think by a firefighter. we think by a firefighter to the medical tent and, really, as she described it, hysterical. there was a person who helped calm her down who she said was a -- described himself as an army sergeant, an afghanistan vet. i don't know whether he was assigned to the medical tent or, like so many other people, there and elsewhere in the commonwealth, just jumped in to help but his name is tyler. that's all we know. tyler. and one of the things he said to her, to calm her down, was to show her his own shrapnel -- a wound or scar from his own shrapnel wound from when he was

in afghanistan. victoria very, very much wants to thank tyler personally so if tyler is out there and listening or reading your reports we would love to hear from tyler so we can connect him to victoria and tyler can get in touch with us by dialing 617-725-4000. if you just get that word out there i'd appreciate the favor and plmore to the point victori would. thank you all for coming. >> all right. there is the news conference. it ends on a note, hopefully tyler will in fact connect with victoria and observe vicely helped her a great deal. we did learn several important details at this news conferences specially from the fbi agent in charge of this investigation. he said possibly a pressure cooker kind of device in these two bombs. key word "possibly." they're investigating it and also investigating the

likelihood that bbs or nails, forms of shrapnel, were included to maim and to kill, cause as much destruction as possible. they believe the bombs were contained in what he described as two black nylon backpacks or bags. one point he called them backpacks. another point he just called them bags. they were contained in those bags. they would have been heavy given the explosives. he did point out that the investigation in his words, the investigation is in its infancy. infancy meaning they are just beginning this investigation. no one has claimed responsibility. no one has said that they were responsible whether domestically or internationally. he refused to speculate on who may have been responsible for this, the key words though the investigation is in its infancy. let's assess what we just learned and digest a little bit with john king who has been doing some serious reporting on this. our homeland security

contributor fran townsend, our analyst is with us as well. first to you, john. these were important details but, clearly, if they have more clues they're not sharing. >> important details and the fact that the fbi special agent in charge right near the beginning of his remarks said he was appealing to the public. do you know anybody who mentioned the marathon? do you know anyone who might have had a very heavy black nylon bag? essentially appealing for tips. that tells you and i'm told by local police sources before this event that they have what they called a frantic review of the video. they believe they have some image of what might be the devices in the area but i was told no evidence as yet. you heard them talking about the methodical review of the video of anybody bringing a suspected device to the scene. that was the fbi appealing for help right there which tells you at this point they've sent that material to the lab but they don't have a signature as yet even though they think they understand the scope of the devices involved. they would lead them to an individual or individuals or an organization. yes the investigation in its infancy but if you track the history and juliet knows this

better than i often you get it like that. they see the device, get the m.o., get the kind of explosive. it takes them somewhere. this leads you to believe unless they are bluffing publicly that again as i said earlier they have a lot more questions than answers. >> clearly, the individuals they may be questioning right now, you don't want to call them suspects. >> right. >> apparently no great leads have emerged based on what we just heard. >> these people are all free to go essentially once they're medically healthy. a couple things out of this which became clear. as john was saying there is a gap in the situational awareness. they have pictures here and here and they don't have this picture. and i just did a stroll down there. it is clear that there are not as many cameras as we thought, as i thought there would be. so i think they're looking for who has that frame. that's why they're appealing to the public. clearly, the person was there. the question about whether the site was secure before the marathon i think is now moot. it was clear before everyone came. someone came in when it became more -- looser, more chaotic --

and dropped something. that is what the fbi agent was saying. someone with a big bag and wean he was there. that is at least hints of where they're heading right now. >> we did learn from governor duval patrick that president obama will be here thursday morning, 11:00 a.m. eastern for an interfaith service. the president will be here in boston thursday morning for this service, 11:00 a.m. gloria borger has been doing some reporting on what's been going on as well. what are you learning? >> i've spoken with a senior law enforcement source who is very familiar with the investigation, says a few things to me. right now as you've been talking about, the investigation is completely inconclusive. he said they believe they had something with the saudi national that evaporated and left them without latching on to anybody or any motive. he said to me it's not a good sign that they're still asking people to send in photographs because that means they're not much of anywhere with this investigation. what he says they will try to do is reassemble a close facsimile

of the bomb and timing device so they look for that signature that john king was just talking about. they ask the question, does this resemble anything we have seen anywhere else? and that leads us to a discussion of the so-called pressure cooker. this law enforcement source allows for the possibility that this could be domestic terrorism again as you pointed out. we just don't know. but he also points to the fact that pressure cookers have been used in a handful of instances related to international terrorism attempts over recent years and he notes in fact that the increasing message from islamic rad calls is to keep it simple and smaller bore. again, we need to point out that these kinds of recipes if you will, using a pressure cooker are readily available as fran townsend has pointed out time and time again on the internet

to be used either by islamic radicals or domestic terrorists. so it's much harder to determine, okay. this looks like al qaeda or it looks like somebody else because the recipe and the equipment is so readily available if you want to try and google it on the internet. >> and they're not all that complicated, difficult to make. fran townsend you're our homeland security analyst. you worked as the homeland security adviser to president bush. this pressure cooker type of bomb, i've been told that they are fairly, pretty evident in afghanistan, pakistan, maybe in iraq and not all that complicated to develop and certainly as gloria said you can go on the internet and get the instructions how to build them. >> that's right, wolf. the component pieces are readily available. it's easy to buy a pressure cooker. the circuitry to put it up --

hook it up to the timing device is not very complicated. and so you're unlikely to get sort of the kind of intelligence and leads that they had hoped for from looking at the signature of the bomb. what we haven't talked about, wolf, the special agent in charge in boston did say the component pieces they collected have been sent to the bomb analysis center in quantico, virginia. they'll be looking for fingerprints, dna, the sorts of things while not a signature for a bomb will lead you -- may lead you to an individual. you know, we talk about whether or not this is foreign or domestic, you know, cause of the explosi explosions and, frankly, we know from experience it could be a little bit of both, right? it could be foreign inspired but a domestic individual or cell that subscribes to an al qaeda-like -- orris lambist ideology. so they're looking at all of those possibilities. >> and, wolf, to add on to fran, my law enforcement source says exactly that, that increasingly,

what they are looking for are people who might be american citizens who subscribe to their ideology and say we don't want you over here. we want you back in the united states. >> you know, we've got to remember that when the boston police chief uses terms like the investigation is cautious, methodical, we should not expect an arrest or big break any time soon. >> the investigation, the fbi agent in charge said, is in its infancy. peter king, the congressman is joining us now from washington, a member of the intelligence committee. congressman, what are you hearing? >> i'm hearing pretty much what fran townsend, your other guests have been saying. as far as the investigation, i've certainly heard about the pressure cookers. i know the pressure cooker was in "inspire" magazine which was the al qaeda in the arabian peninsula internet magazine which is propagated here in the

united states. also, know that it has been used obviously in afghanistan as has been said. it was also a version of that was used in the 2010 times square bombing. so, again, it does have islamist links. again, it could be used also by a group like a white supremacists group. it is important to realize as fran was saying that many of the al qaeda operatives today certainly for the last four or fives years because we've done such a good job of keeping al qaeda out, al qaeda is using sympathizers here in this country who have clean records. for instance shahzad who was the times square bomber in 2010 had a perfectly clean record. going back to zazi the subway bomber in new york in 2009 also a totally clean record. so it could be a combination of domestic and foreign. that really is the new war we are facing here in the u.s. with al qaeda. they go for smaller attacks and use people under the radar screen. that doesn't rule out somebody who is not part of al qaeda.

>> what do u.s. officials say to you about the fact that 24 hours later no one has claimed responsibility. what, if anything, should we discern from that? >> it does seem to mean something. in the past invariably al qaeda or its affiliates do claim responsibility. for instance with the times square bombing i believe within 24 hours the pakistani taliban claimed responsibility using that as an example. al qaeda in the arabian peninsula used to claim responsibility for instance like with the airline bombing they attempted in 2010 in october. so it is significant or at least raises questions if it is al qaeda or islamist why no one has claimed responsibility. unless it is a lone wolf who is self-radicalized and would not have the capacity really to claim responsibility without being caught. >> as far as the bomb as it was described by the fbi agent in

charge, congressman, placed in a black nylon backpack or bag with bbs, nails to be used as shrapnel, to maim and kill as much as possible with these pressure cooker devices, is that a signature of some -- have there been previous bombings like that with that kind of bomb infrastructure if you will? >> well, again, the infrastructure as far as the pressure cooker, that is al qaeda. it has been in the past. doesn't have to be al qaeda. and also as far as the mass killing of civilians, since oklahoma city and the olympics, virtually every one of these mass killing attacks on civilians has been carried out by al qaeda. so, again, that is more to the signature of al qaeda. generally you find the white supremacists groups, aryan nations, who carry out attacks, it's not these random attacks on

large concentrations of innocent civilians. that's been -- they're usually attacking a government building or something along those lines. equally irrational but as far as the signature type, al qaeda is more associated with attacking iconic event which this was, attacking an athletic event which this was and also whether it be carnage to innocent civilians for the shock effect. apart from those who suffered so badly the shock effect it has on the country and general and the city of boston in particular. and also we have had al qaeda in the arabian peninsula through "inspire" magazine calling for attacks on athletic events. >> congressman, thanks very much for your analysis. but i just want to point out to all our reviewers the fbi, the governor, the mayor, the police chief in boston, they are saying it is in its infancy. we don't know. there are no hard clues yet but we appreciate your analysis of what is going on.

>> wolf, i fully agree and i was just giving possibilities. i agree this could turn out to be something all together different. you were asking what these could be signatures of and i was describing in that context. i'm not saying that is who did it at all. >> right. i just want to be precise that you don't know. >> no. >> none of us knows. >> absolutely not. >> the fbi and the police chief here, they don't know. they're looking at the evidence and will come up with an analysis obviously once we get more information. thanks very much. >> thank you, wolf. >> we'll continue our nonstop coverage here in the situation room. coming up cnn's dr. sanjay gupta goes into a hospital here in the bonnett area to talk to the doctors who saved the lives of some of the seriously wounded patients. then frame by frame by frame, image by image, what investigators can learn by studying the video and the photos of the boston marathon bombings. ♪

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we're just getting this in from boston university here in boston. a statement coming out, saying the third death, the third person killed in this boston marathon bombing yesterday, was a graduate student at boston university. i'll read the statement coming in from the university right now. one of the victims killed which blasts at the boston marathon on monday has been identified as a boston university graduate student. the student's name has not been released pending permission to do so from the family. the student was one of three friends who watched the race near the finish line. another of the three students also a bu grad student was injured and in stable condition at boston medical center.

robert hill, the dean of marsh chapel, visited the injured student monday evening, and yesterday afternoon. he reports that she underwent surgery on monday and on tuesday. she is doing well, says hill. she and her friends are around her as she will soon have her family around her as well. the third bu grad student who was at the finish line watching what was going on, according to boston university, was unharmed, uninjured in this blast. but once again, a graduate student at boston university is the third death in this boston marathon bombing. our chief medical correspondent dr. sanjay gupta who is a neurosurgeon is joining us with more. many others at other local hospitals. sanjay, you've been speaking with your colleagues, the doctors there, what are they saying to you? >> well, you know, after the

explosion, within 15 minutes, wolf, patients started to arrive here. so things happened very quickly, as you know. in part because there were so many medical capabilities there at the end of the race. within the first 60 minutes is when they got the vast majority of their patients. and it was very busy. i mean, the e.r. was already full. they had to create space within the operating areas. they opened up seven operating rooms right away. all of this was happening quickly. i got a chance to talk to some of the doctors working in the e.r. they're speaking out for the first time about some of the things they saw. and some of the time it took to process this as well. as with most teaching hospitals, wolf, residents play a large part of the care. and one of them is brendan norwood, a fourth-year resident, in the final year of his e.r. residency. listen to how he was processing things today. >> there was sort of a waiting period where there was a lull, waiting for more patients to get there. until we sort of got word that

this was going to be a -- where we're really doing our job. i think that's where i started viewing sort of the feeling that what i just witnessed -- thinking about it in the larger context, talking to my colleagues about the things they'd seen. i think that was the toughest part. >> they finally got a chaps to process, wolf, as you heard there, some of what they've seen seen. another thing is, wolf, when you talk about a hospital like this, brigham and women's, very few times can you say they've never seen anything like this. that's what i kept hearing over and over again, from the chief of surgery, the chief of the emergency room. they just had never seen anything like it. it doesn't mean they weren't prepared, they hadn't trained or done drills, but this was a new event for them, wolf. >> i was speaking myself today, sanjay, with a trauma surgeon who's been dealing with a lot of the victims at a hospital here

in boston. he himself had been a runner in the marathon, and as soon as it was over, he heard what was going on, he went to his hospital and started doing surgery. he's been doing it all day. what he said to me was intriguing. you can explain what he meant by this. when you're dealing with trauma, and serious surgery like this, you can only do a limited amount at any one point, then you have to wait for a while and do a second round of surgery. otherwise it's not going to work. sometimes you have to go three or four or five times. explain what he was saying. >> oftentimes, and this is difficult to talk about, to some extent, wolf, but oftentimes with amputations and with tissue that has been very injured as a result of the explosion, you're going in there and basically trying to figure out how much tissue and bone and the soft tissue and muscle you can save. and so you try and obviously save as much as you can, and sometimes that requires staging

of operations. going back and taking a look, sometimes debriding or removing some of the tissue that has not survived. you do this over and over again until you're sure that you have an area that is clean. clean enough to actually close skin over that area. again, it's tough to describe, wolf. but that's typically what they mean, especially with respect to amputations. >> this is a trauma surgeon that i spoke to, a veteran of the wars in afghanistan, and iraq. and he said he hasn't seen injuries like this since he was over there. you certainly can appreciate what he saw. these injuries are pretty much the kind of injuries, sanjay, when you were there in iraq, or afghanistan, the kind of injuries you saw. and that you treated. >> yeah. you know, i had not seen them during my training, but you're absolute hi right, having spent time in iraq and afghanistan, i've seen these types of injuries now. and one of the chief of surgery

here again, dr. ziner, likened these types of injuries to ied explosions, which you've heard before. that means a very specific thing. it's not just the blast of the injury, but it's also the shrapnel, the secondary blast of the injury. that can cause the types of injuries they're seeing here where the skin and muscle are so dramatically affect, wolf. >> sanjay, i know you're going to have a lot more reporting later tonight on "ac 360." we'll stand by and get your report then. thanks so much, sanjay gupta, over at one of the hospitals here in boston, watching what's going on. authorities in the boston area, they are appealing to people to come forward with any photos or videos that may help the investigation. our pentagon correspondent chris lawrence is joining us now. chris, what can investigators learn from the images of these two bombings? >> yeah, wolf, you've got to remember that people had been taking pictures and shooting video of that finish line for hours before that explosion.

so any one shot, any one frame could hold the clue to help investigators break this case open. every angle of these explosions has the potential to tell us what happened. the runner were right there, but many of them just kept on running to the finish line. >> right. the runners seemed to have been shielded by all the individuals who were standing around the device. >> reporter: michael bowshard said the bombs were likely placed on the ground or two to three feet above it. but there's no windows blown out. and no crater. and that tells bowshard this was not a high-intensity bomb to destroy buildings. >> with a low-grade explosives and small amount of explosives, you won't really see a crater. >> reporter: but all of that power suggests something was used to maximize the blast.

>> all the hot gases have to be able to build up enough. the pressure becomes so overwhelming, that then the container then explodes. high-grade explosives, you don't need to contain them like low-explosives. >> reporter: how does someone set off a second explosion, just 12 seconds after the first? >> this second explosion, that is a long block to the first. >> reporter: the distance between the two blasts is significant. with the crowd there, it would probably take you probably ten minutes to walk that distance with those crowds. >> reporter: he said it would take two people, a pressure switch set to activate by someone stepping on it, or one man with a timer. >> it is very risky to walk around with a timer. again, you could be detained, you could be stopped. the crowds could be too big. you'd have to obviously stop it. >> the problem there is that all

the materials that are suggested in this