from the new york and new jersey explosions this weekend. string of bombing attacks. started saturday morning. in seaside park, new jersey. that was followed by a large pa. that was followed by a large explosion in the chelsea neighborhood of manhattan on saturday night. that was followed in the overnight hours last night by a further explosion in elizabeth, new jersey, as a police bomb disposal robot tried to defuse another group of devices found on the street by a couple of very, very lucky homeless guys that defendant's exhibit themselves get hurt in handing tho -- handling those devices. that was followed this morning by a shootout on the streets of lyndon, new jersey. the man that is now hospitalized with multiple gunshot wounds. he has been charged tonight with five counts of attempted murder. that number may seem strange. what's interesting about these charges is this man has want yet

been charged with anything related to his alleged role in blowing up those bombs either in new jersey or new york. what he has been charged with -- he has been charged in conjunction with that shoot-out with police officers this morning. super interesting. we'll be talking a moment about why that is and what we know about the case against him. we've also just got brand new details tonight about the construction of the bombs in both new york and new jersey. there are very unusual details and what has been reported about the construction and the makeup of these devices, to a certain level, all homemade bombs by definition are a little strange. they're all a little different. the details about these bombs that have been recovered and the ones that exploded in new jersey and in new york, the details about how they were built are weird enough details that they may actually be helpful. they've been sorting out where he may have been coming from and where he learned his bombmaking and any potential links to

terrorism. we have those details coming up in just a second, along with some experts here to help us understand their significance. we have further news on isis taking responsibility for the minnesota stabbings that took place. it's seemingly unrelated to what happened soon thereafter in new jersey and new york. we have isis directly claiming responsibility for that minnesota attack, and there are interesting questions to be raised about what it really means. there were at least three terrorist attacks in the span of 12 hours. there's still a lot of news. there's also a bunch of other news beyond the terrorism stories tonight. there's a lot going on, for example, around united nations. united nations general assembly kicks off tomorrow.

security in our nation's largest city, security of new york city, is also mega around the u.n. general assembly. you cannot imagine what it is like here now. simultaneously, this multiple from site bombing investigation going on and the general assembly starting tomorrow. you would never know there were enough law enforcement personnel to be anywhere else in the country for the number of them you see out in the streets of manhattan and at new york landmarks today. president obama is dpu to address the u.n. general assembly tomorrow. it will be the last time he does that as president. today and tonight hillary clinton was in new york meeting with the leaders have japan and ukraine and egypt. the republican presidential candidate donald trump also took a meeting tonight with the egyptian president. feel free to wrap your brain around that for a while. that debate happens a week from tonight. those details coming up in just

a bit. beyond just gary johnson not making that first presidential debate, which he previously said would be game over for his candidacy. beyond that, the libertarians also got some further bad news in the last 24 hours. this is a ten-pound show, and we have to fit it in a five-pound bag. let me start with this hard to pronounce series of words. hexamethylene triperoxide diamine. i think that's how you sue it. more easily pronounced as hmtd. hmtd. it's a peroxide based compound that's explosive. because it is peroxide based it is a little similar to a now well known similar explosives called tatp. it's a compound we've learned

about the last few years. this is even a little more unstable. a little more likely to go off accidentally if it's subjected to any shock or impact. these peroxide-based explosive compounds, they have become well known even among those of us that aren't experts in this field because they keep getting used. they keep getting used by al qaeda linked and isis linked bombers all over the world. the contacts in paris and in brussels, the 7-7 bombings in london, boston marathon bombs of 2013, peroxide-based explosives. those compounds, they're not easy to work with. they can be dangerous for the bomber unless the bomber really knows what he or she is doing. they're also becoming basically a signature explosive for islamic terrorist groups. now, we do not yet have absolutely clear information about the devices that either exploded or were recovered in those several different sites this weekend.

we don't have totally clear reporting on it. there's a bunch of devices that are being attributed to this one 28-year-old afghan-american suspect that was shot by police this morning in new jersey. here's the thing. there are reports tonight that the explosive compound in the one pressure cooker bomb that he apparently set in chelsea, but it did not explode. a bomb that was found on 27th street in manhattan was found intact after the first bomb exploded four blocks south in manhattan. it was taken intact. first by the nypd and then at the fbi. we're told it's at the fbi's explosive lab in qauntico. the explosive compound that was in that unexploded bomb, the one recovered in chelsea, that compound was hmtd. one of these peroxide-based explosives. here's why that's interesting. here's why that's interesting and potentially strange. there are also reports tonight that the other pressure cooker bomb, the one that did go off to such terrible effect on saturday

night. the one that injured 29 people. we are told tonight that that pressure cooker bomb was made with a whole different kind of explosive. we're told tonight that the explosive material in that one, the one that went off, is a combination of ammonium nitrate and aluminum powder. when you combine those two components, it does create an explosive mix. a reallytively common one. those two components are the components of some widely available commercial products that people use at gun ranges when they want a shooting range target that doesn't just get a bullet hole through it. it explodes when you hit it with a rifle round. i know that sounds a little bit over the top, and i'm sure a lot of people use sploegd targets just because, oh, gee whiz, i want something to explode. it does sort of make sense towards target shooting at a very, very long distance. one of the things that makes sense about exploding target for shooting from a very, very far

away and you need to know with the naked eye whether or not you hit your target. sploegd targets. that said, also, whoa, exploding targets. it's interesting already, right? if the reports about the nature of these two bombs looks to be true. that means that we have two bombs structurally similar. both pressure cooker bombs. they were made with two very different types of explosives. that's weird and interesting when you are talking about one bomb, right? beyond that this same suspected bomber is also being ascribed responsibility for another completely different type of bomb. in manhattan both on 23rd treat and 27th street there was a pressure cooker made into a bomb, right? in new jersey in seaside park at the site of a fun run and in elizabeth, new jersey, where a couple of homeless guys found them sitting on a backpack in a trash can. we are told they were pipe bombs. once again, there's yet another

weird detail that is hard to explain and hard to imagine the significance of. we are really talking about one bomber. that device that blew up in seaside park, new jersey, which did not injure anyone, blew up inside a plastic trash bin at the start of that 5k run and didn't hurt anybody. that appears to be on a bunch u bundle of three pipe bombs and the explosive material in those pipe bombs was reportedly yet a third kind of explosive material. remember the first pressure cooker bomb, ammonium nitrate and -- >> that seaside park bomb was neither of those things. the explosive material in that bomb was apparently black powder. if if you want to get the spur one last twist, if you want to get even weirder, consider that last crush of bombs found in elizabeth, new jersey, again, those were pipe bombs like the other new jersey device, but those ones were apparently stuffed with hmtd.

like the pressure cooker. how does this make sense? you've got three different explosive compounds all of which potentially are dangerous. you've got two different bomb designs. between the two different bomb designs, you have sort of a mixed bag in terms of which explosive compound you're using in each. between the three bombs in seaside park, i think maybe one of them went off. in ermz it of the five bombs in elizabeth, none of them went off before the police got there. one only detonated when a police robot was sent in to clip wires. between those eight bombs and then the two pressure cooker bombs, one of chemical went off and one of which didn't, you have basically two purposeful explosions, seven devices that never went off at all, and one that only went off in the process of being defused after it was handled roughly by a couple of guys. huh?

how likely is it you get one bomber that's practiced enough with this stuff. you've got one bomber making all ten of those bombs all in different ways and miraculously not killing himself and not killing anyone else even with ten bombs to work with. does that make sense technically? how does that make sense? what does that tell us about where he was learning his bombmaking? whether it's conceivable he did this, both, alone and without anybody noticing what he was up to?

>> those are the links we know. according to law enforcement there are some explanatory links between those disparate bombs, those bombings and this one suspect they've got in custody after he shot at two police officers this morning. in terms of other people that might have been in on this or ongoing terrorist concerns or ongoing terrorist organizations, anybody that's still had connections on the bomb might still be loose. should we expect there are other bombs out there from the same maker? at this point we do not know. that said while all of this has been unfolding in new york, meanwhile, isis's media arm, which is called amaq, they are overtly claiming responsibility for the knife attack that happened saturday night at the crossroads center mall in st.

cloud, minnesota. after stabbing eight men -- we earlier thought it was seven. it's now eight men and one woman and a 15-year-old girl. this 22-year-old somali-american security guard had a great misfortune to run into a man who was a licensed fire instructor and trained competitive shooter. he is literally a man who has won medals in competition for practice shooting. he trains other law enforcement officers specifically in high pressure handgun shooting techniques. that's who he ran into. that was the end of 22-year-old dahir dahan. he was born to a somali family in kenya and raised in many inna since he was a toddler. there's no radical connections or radical convictions or ok any sort of watch list. isis called him a soldier of the islamic state. now rrks this is not the first

time that isis has claimed responsibility for an attack that happened in the united states. you'll remember this with the san bernardino attack, the orlando mass shooting. the question in this case is whether this claim of responsibility for the stabbing in st. cloud, says whether it is effectively just isis crowing over this attack, expressing their pleasure that it happened and wanting credit. i mean, at this point do we know if that claim of responsibility indicates any meaningful line of connection or communication or even inspiration between that 22-year-old attacker in st. cloud and the islamic state in iraq and syria? the suspect is not available to be questioned. he is dead. meanwhile, in new jersey ahmad rahami, he is alive. he is in the hospital and charged with five counts of attempted murder for the gun

battle. they have not yet charged him in conjunction with all three of those inexplicable strangely and diversely constructed bombs in those two states. joining us is the "new york times" correspondent specializing in al qaeda and isis. thank you for being here. a lot of work, heck of a workday for you today. >> thank you. >> let me start with saint cloud first. you have said in the past that there is a fairly recognizable pattern in terms of isis claiming responsibility. they don't let stuff necessarily go too long before they do it? >> they're looking for certain signs. they're looking first to see if the person who has done this attack is a muslim, sunni muslim. secondly if he is doing it in an ideological fashion. so, some of the clues that have come out of saint cloud do indicate that. there was a reference to allah in something he said. there was at least one witness that said that he tried to triage muslims from non-muslims asking one of the people he was about to stab, whether he was, whether he was a muslim.

so there are those two indicators. in their statement, isis accredits their claim of responsibility to a source. so, we don't, we have no idea if that is, if that its true. if there really was a source. but what we have seen in the past, including with the attack in garland, texas, omar mateen in florida and host of attacks in europe, is that in the initial hours and days after the attack, law enforcement officials are often, often puzzled. by this they initially state there is no, known link. with time and with their communications, being dug into, you eventually find some sort of link to the islamic state whether it is just an inspirational one where the person has been imbibing their ideology, or whether as we have seen in very recent cases in europe there is an actual tie through a communication via encrypted apps, telegram. virtual planner of the islamic

state. a number of them. their basic job ties reach out to, radicalized young men. and try to move them from just the radicalized stage to the violent stage. >> in terms tough the investigatory tools, that u.s. law enforcement has, though encrypted messaging techniques do they have access to them? know enough about how to find the things that they find them when they do exist? >> i think what we need to wait and watch for is -- is are they able to identify this young man's facebook account. a young man, most likely he has one. twitter profile. and then his telegram account. nowadays, the telegram account the most important i think. isis has the a host of encrypted channels.

in various langues. for various communities. and it is on the channels that usually the discussions devolve. from there you can piece together how an attack is linked back. >> new york, new jersey bomber. i lay out what i find puzzling for the construction of the problems. let me ask your basic reaction to that. do you think what we know of construction of the bombs is interesting, unique, or potentially important. >> i have to say my own source that i have been consulting on this law enforcement official has identified the material that has been used in only two of the, of the four, devices. and, what he is telling me is that it is, hmtd. >> okay. >> other ones, my own colleagues. >> seaside park and 27th bomb that didn't explode? >> elizabeth i think. elizabeth and 27th street. now that explosive in and of itself is weird from my point of view. it is a peroxide-based explosive like you mentioned unlike tmtp, it is much more volatile, it includes products, peroxide, the raw ingredient are easy to have in the west. >> they're not illegal. obtain them. as long as you don't obtain them from the same place, you won't raise suspicions. >> exactly. exactly:tatp, versus hmtd, i am told hmtd is much more volatile. much more, it is much more

susceptible to explosion, accidentally. so, that something jes in and of itself if you are going to make the explosive, you have skill, otherwise you are likely going to hurt yourself in the process. one of the explosive experts i spoke to today, if it is really is hmtd, you expect some chemistry. you expect that the person had some knowledge at least, yes possible he could have learned it online. unlikely. but it is possible. and that there would have been a lab. there would have been a dedicated space, some where, where he had done this. and, these materials in, in these quantities would have given off a smell. she says it smells fishy. literally like fish. it is possible that this -- this lab, will be found at some point. but, that said, it is a departure from what i have seen. all isis plots in europe to this

point have been tatp. so that said, the other thing that is interesting about this case is on the one hand if you assume, as, as seems to be the case with the, with the dialogue we have seen so far, that it really is one bomb maker. you assume four location in two different states. on one hand something very ambitious. right? it's -- it's equally ambitious to perhaps november 13th attacks, foiled an didn't go off. on the other hand, you have something very amateurish about it. so, one, one of the pressure cooker bombs including the fingerprint of the bomb maker. every single manual online or otherwise for making these things teaches the bomb maker you have to use gloves, otherwise that, that exactly problem is going to present itself. they will be able to trace it back to you. secondly, one of the detonators, one of the cell phone detonators was one from, from the bomb

maker's family. or from the suspect's family. we don't know yet for sure if he is the bomb maker. a rookie move. use a burner phone not traced back to somebody you know. therefore helps law enforcement. >> not a suicide attack. not sticking around for the explosion. so many weird combinations of very advanced, both advanced and, like high level and low level stuff simultaneously with the same thing. >> we don't yet understand the story i think. >> if i could add. my colleagues are reporting now from my colleague adam goldman. law enforcement officials are confirming now at least three trips to pakistan. >> in addition to trips to afghanistan. >> in addition, yes. and so we have 2005, we know he want to karachi. 2011, pakistan. don't know where. and then the most recent trip was, april 2013, to march 2014 in the city of queta in pakistan, queta is a hotbed of militancy. however, officials are saying he was staying there with, with family, members of his that were in the refugee camps. so any one of the trips could be explained him going back to see family. but in light of what happened,

it's hard not to also look at it through the optic of, of, of what these cities imply in terms of militancy and islamic radicalization. >> correspondent for "the new york times" focuses on al qaeda and isis and who just advanced the story considerably in terms of my understanding. but i still feel like, there is so much more explaining that need to happen before it makes sense. thank you. >> my pleasure. awe match of more ahead. stay with us tonight. reatments t don't give you clearer skin. be the you who controls your psoriasis with stelara® just 4 doses a year after 2 starter doses. stelara® may lower your ability to fight infections and may increase your risk of infections and cancer. some serious infections require hospitalization. before treatment, get tested for tuberculosis. before starting stelara® tell your doctor if you think you have an infection or have symptoms such as: fever, sweats, chills, muscle aches or cough. always tell your doctor if you have any signs of infection, have had cancer, if you develop any new skin growths or if anyone in your house needs or has recently received a vaccine. alert your doctor of new or worsening problems,

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>> we are going to have more on the bombings later this hour. including this interesting question about the weird tech that is involved in these bombs. we are going to have a little more expert opinion on that. a lot of other news to get to including brand new info about the first presidential debate. basically about to happen. coming up very soon. we got details on how that is going to run. lots to get to tonight. stay with us.

tonight we got the details. logistical details for the first presidential debate one week from tonight. here's what you need to know. one week from tonight. monday, september 26th. hofstra university in hempstead, new york. there is a single moderator, lester holt of nbc news. it is going to start at 9:00 p.m. eastern. run for 90 minutes. it will have 0 commercials. and now, as of tonight we know how they're going to divide up that noncommercial 90-minute time. turns out they're going to do it in six segments of 15 minutes each. they're going to do two 15 minute segments on america's direction. two 15 minute segments on achieving prosperity. two 15 minute segments on securing america.

so, there you have it. little vague, i know. but i think that's kind of the point. you don't want to give them too much direction or they will cram for what they know is on the test, right? the commission on presidential debates announced on friday that there will be no minor party candidates in this first debate next week. or, in the vice presidential debate the week after that. libertarian candidate gary johnson complaining, i think rightfully that ross perot had lower national poll numbers in some polls, than gary johnson does right now. at a time when ross perot was invited to be part of the debates in 1992. arguably true depending how you look at the numbers. doesn't change the fact that gary johnson this year, came nowhere near qualifying for this year's debates. according to the rules and criteria publicly set out well ahead of time. that said. gary johnson may have more pressing things to worry about

at the moment other than the debate. carl bernstein of watergate fame reported over the weekend that gary johnson's well-regarded runningmate, former massachusetts governor bill weld might quit as gary johnson's running mating over concerns the libertarians could play a nader-esque role this year and tip the race to donald trump. they're both absolutely denying the report. there is no way bill weld its quitting the ticket. that provocative report does exist. as does gary johnson's own persistent problem of saying extremely dumb things about extremely serious subjects. last week it was the almost unbelievable spectacle of him answering a qution about the war in syria by saying, what is aleppo? like it was an obscure flavor of ice cream or some fancy foreign version of alpo dog food. never heard the word before. now gary johnson has weighed in on the attacks this week end. where 29 people were hurt in a bomb blast saturday night in manhattan. hours after ten people were stabbed at the saint cloud,

minnesota mall. here was his response. >> well, first of all, just grateful that nobody got hurt. >> actually, never mind. perhaps not making the debate is a blessing in its own way. lots more ahead tonight stay with us.

three years ago this past week, a columnist at bergen record newspaper in new jersey started reporting on a weird stubborn hard to explain days long traffic event that seemed to

come out of nowhere. it's, it's new jersey. so it is not that weird for a newspaper to have a traffic columnist. but what was unfolding in the little town of fort lee, new jersey, accord to bergen record columnist. a commuting disaster. one question -- why would the port authority purposely quadruple commuting time for some of the people who live closest to one of the nation's busiest bridges? that was september. three years ago. by the following january, the bergen record was able to answer the question when they broke the news that the order to close down access lanes onto the world's busiest bridge actually came directly out of the office of new jersey's governor chris christie. it was bergen record reporter

who got ahold of the smoking gun e-mail tying lane closures. it was an e-mail from deputy chief of staff saying "time for traffic problems in fort lee." it was also the bergen record first reported the man who would plead guilty to planning the closures, david wildstein was considered the direct line to the port authority. the reveal in the wake of the scandal, the port authority chairman, and christie ally, david sampson, forced to resign from the gig. the second largest newspaper. and that paper along with a bunch of other really good new york, new york area and new jersey media outlets, bergen record devote untold hours and gallons of ink not only to the bridgegate story but also to everything else that makes new jersey politics so new jersey. and that's why it was remarkable and not at all funny when this past week, as the jury was being selected and seated, in the

biggest political trial to hit that state in years, as the jury was seated, that day, last week, the bergen record announced it is laying off all most half its newsroom. the paper was just recently acquired by big media conglomerate, that conglomerate says they're about to cut 130 newsroom positions at the bergen record. this is -- bad news for new jersey. it is also bad news for anybody who cares about transparency in local government. anybody who might conceivably like to know what appears to be a mysterious commuting disaster is in fact allegedly a large scale act of political retribution by a man who might end up being president if stuff like this isn't reported by his dogged local press. the bridgegate trial opening statements started today. and bridgegate today claimed a large portion of chris christie's political slp. even as one of the papers key to unraveling the scandal got scalped itself by the local news

business. more on that in just a moment. but in the meantime, in this commercial break, get online, and subscribe to your local paper. actually pay to subscribe to your local paper. your country need you to do that. go on. go on. go on. go on. if you have allergy congestion, muddling through your morning is nothing new... ♪ introducing rhinocort® allergy spray. powerful relief from nasal allergy symptoms, all day and alnight. ♪ try rhinocort® allergy spray. muddle no more®.

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and more radiant in just one week. aveeno® naturally beautiful results® today was opening day in the bridgegate trial in new jersey. you know the story, right. a top political appointee of chris christie and former deputy chief of staff are both facing felony charges over what prosecutors say was a criminal scheme to inflict terrible traffic on one new jersey town on purpose. as a political vendetta against that town's may your who had the temerity not to endorse chris christie for re-election. prosecutors kicked off opening arguments today by asserting that governor christie knew all about it. oh. the u.s. attorney's office, prosecutors, they said today in their opening statements that over the course of this trial, they're going to prove that christie knew about it. now, we have long known that the defendants in this case, would probably be trying to blame chris christie for the lane closure saying he knew it in

order to undercut the prosecution case against the smaller fish. but the defense taking that line is one thing. now the defense and the prosecution. the prosecution is also taking it as a given and says they will prove that governor christie knew about the scheme while it was unfolding, they say they will prove it in open court. and that is -- that is -- governor christie, important to say is not on trial here. but his name came up dozens of times today, already he has become central to the trial, on both sides. now what happens? joining us now is matt katz, covering the trial for the radio, and author of "american governor, chris christie's bridge to redemption." matt, thank you for joining us. >> thank you, rachel. i wanted to call in sick and go to the trial today. was it -- when the prosecutor said, chris christie knew, was that a surprise? >> for sure. i mean we haven't heard that at all. we heard one indication of that from a defense attorney. but to hear this from the

prosecutor so early on, on day one. there is a picture of chris christie and the conspirators hanging out at a 9/11 ceremony, september 11th, at ground zero while the lanes were closed. always suspicion as but that. what the prosecutor said, chris christie was talking to the guys about the traffic jam. >> while the pictures were being taken. >> that they were bragging to christie about the traffic jam. and, that the mayor of fort lee which was having public safety issues because of the massive traffic jam, ambulance drivers getting out of the vehicle running to the scene of incidents. they were bragging to the governor that they were ignoring calls, e-mails, text messages from the mayor of fort lee. >> do the prosecutors give any

indication of how they will prove this dramatic assertion about the governor? >> likely based on the testimony of david wildstein, charged in this but cooperating. and his testimony is, is, really the linchpin of the trial. he has testified against both defendants in exchange getting a more lenient sentence. >> in terms of the strategy, i understood or could fathom, not a lawyer, i could fathom while the defense would say why you are going after the small fish. this was a political vendetta. serving one man's interest. chris christie scheme. not the scheme of my clients. why is the prosecution also making the same point? >> they're making the argument. there is a culture of revenge and retaliation that ran up and down the whole administration. they brought up examples of both carrots and sticks the administration would use. tickets. free tickets to a giants game. may your who they want to endorse. tour of ground zero perhaps for a mayor. then also they were showing that there were revenge tactics ordered by the governor. canceling meetings with the may your who didn't endorse him. or, causing a traffic jam. so they're trying to. >> show a pattern of behavior. pattern of action by that governor's administration. >> which is what is damning for chris christie. everybody in the courtroom. all the lawyers have no interest in making him look good.

they all have an interest in according to their legal strategies in taking him down. >> if they do prove it. then he is going to have to answer for asserting over the years no knowledge knew nothing abit. >> he will probably continue to say it. >> matt katz, covering the bridgegate trial. come back over the course of the trial. keep telling me until i can call out sick. >> yes. >> thank you, matt. stay with us.

one of the sort of overwhelming details about the bomb incidents in new jersey and new york this weekend, is just the sheer number of bombs. that were planted or at least just found across new york and new jersey. right? three pipe bombs in seaside park, rigged into a single device. two big separate pressure cooker bombs in new york city. another five bombs at the train

station in elizabeth, new jersey. multiple pipe bombs in a backpack. the makeup of all of the bombs as we have discussed earlier this hour, a little weird. diversity of the bombs. diversity of the explosive compound in the bombs. the number of the bombs. it's weird. it's a little scary. but that strange fact about this -- this crime, these terrorist attacks, they may also be able to help us understand more about what kind of attack this was, whether it is linked to something bigger than what it already seems to be. we have more on that ahead with a very well-informed expert. stay with us.

did you know that your son

was doing this? >> no. >> you had no idea? >> no idea. >> when you hear now that he has been accused of this, do you believe it? do you believe it? sir? >> i'm not sure what is going on. >> you are not sure? >> i am not sure what is happening exactly. but i think so. it's very hard right now to talk. okay. thank you. >> that was the father of suspected bomber, ahmad khan rahami. speaking exclusively to nbc news earlier today. whether or not those close to the suspect knew that he was potentially planning these attacks or building these devices right now those devices are really interesting. authorities are sitting on potentially a forensic gold mine in terms of evidence. not only do they have, multiple bomb blasts to investigate, they have also got multiple device that did not explode. how far can that go in terms of helping us understand what happened here? and basically the overall size of this plot? whether it is linked to anything else? joining us now is malcolm nance, a counterterrorism analyst, and author of "defeating isis."

malcolm, great to see you. thank you for joining us. >> good to be here. >> when we talked about bomb attacks in the past, you sort of described an unexploded device as kind of the, the alpha and the omega in terms of forensics and trying to understand where this, this came from. do you have high hopes in terms of that intact pressure cooker bomb and intact pipe bombs that have been recovered? >> oh, yes, we are going to learn quite a bit about the, not just about the bombs themselves. bombs are just, you know devices and systems that the terrorists build. it's about why he builds them. how he builds them. why did he choose that particular device? why did he choose that particular explosive? we will learn quite a bit about this individual. also where did he get the expertise to do this? and i think we are, you are going to find some fascinating information about that is, i'm sorry as that comes out. certainly it might be related to his trips to pakistan.

but as soon as i heard pressure cooker bomb, the word afghanistan came to mind. and any body who served in afghanistan knows pressure cooker and crock pot-style bombs are, are the rage over there. and the last time we saw it in the united states was the brothers and the boston bombing. >> what appears to be diversity of materials and techniques putting these together. some pipe bomb, pressure cooker bombs, htmd, some black powder, some ammonium nitrate, aluminum powder. combination. that diversity of techniques and materials, what does that say to you? >> well, that tells me that the bomber himself was experimenting with all of these devices. and all of these methodologies. in order to try to get the right mix down. what's going to be most interesting over the next 72 hours is, do we find this man's

bomb factory? okay. the bomb factory, the place where he actually assembled them, if it wasn't in his bedroom, which i doubt. usually a second ear place, which is very clean, very neat with an electrical bench. we are going to find out whether there were more materials. whether he intended more bombings. we got eight pipe bombs which is, which is about right. because bombers tend to build pipe bombs in pairs. or, you know, rarely do we have like seven. we will always have two, four, six, eight. and then the pressure cooker bombs themselves which are devised like al qaeda's anti-personnel devices with layers of explosives in between layers of ball bearings, in order to create the most significant anti-personnel effect. so, once those things, once that bomb factory is found. and the fbi's labs and they take that device apart. they're going to compare it against every pressure cooker bomb found in the world. same thing with the pipe bombs. the pipe bombs are usually used here in the united states by anti-government extremists

generally fill those with black powder or pyrotechnique powders. >> if it turns out htmd, peroxide based ex-plea tough is, hmtd, is one of these the basis of one of the bombs does that imply to you either a level of training, or a level of sort of chemistry sophistication or anything else, its that, a, a more difficult material to work with? >> yeah, it is a much more difficult material to work with. peroxide based bombs. you know i am wondering and certainly even though this attack was amateurish in its delivery, he had, he had appeared to have some type of preparation. you know, bombers choose the materials they work with either because of the availability. or, on the other hand, when they went through baby bomb builder school whether they actually became more proficient at

building one type of bomb. he may have gotten the htmv build pattern down very well at bomb makers school and failed at tatp and all of these other chemicals. he just started off with the basics, which is always black powder, and then moved his way up to flash powder, which is the nitrate based ones, and maybe at school he got proficient at building htmd or -- rather than tatp. >> executive director of terror asymmetrics pressure. good to see you. >> my pleasure. >> still ahead, an intriguing open case that we learned about today. stay with us. psoriasis. be the you who shows up in that dress. who hugs a friend. who is done with treatments that don't give you clearer skin.

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>> just one last point i want to raise with you tonight on the issue of the bombings this

weekend in new jersey and new york, which injured a total of 29 people before that alleged bomber was shot and taken into custody this morning by the police. we've been taking a close look tonight at the fact about the ten bombs being attributed to that suspect. this bomber apparently made at least four different kinds of bombs. ten bombs, four different types. one of the pressure cooker bombs used ammonium nitrate and explosive powder, and another one hmtd. other used black powder. that surprising range of techniques and materials is prompting new questions about a totally different event from earlier this year in new york city on july 3rd. watch. >> it was chaos in central park. this video was taken minutes after 18-year-old connor golden's foot was severed in an explosion in the middle of the park. connor's friends told us they had no idea what caused the blast. >> we really don't know.

>> reporter: police believe the teen and his friend were climbing on the rocks in the park. connor stepped on what may have been a plastic bag filled with an explosive material. that set off the blast. >> that was july, right? that was july 3rd. police that day said that college kid that stepped on a hopemade experimental firework left behind by who knows? he should tell you by way of good news that connor golden is back walking and back at college. okay? at the time of that accident when he came out of surgery and spoke to his parents, he told them "i stepped on a bomb." well, whatever he stepped on, police still have not identified a suspect. police lab tests reportedly found traces of the explosive tatp from the blast that day. tatp was used in the paris bloms last year. it was used by richard lee, the shoe bomber in 2001. it was used -- tatp is used in a lot of terrorist attacks. it's relatively easy to gin up from stuff you buy at the store

that's not illegal. the relative ease of getting tatp and its popularity among bomb makers, the ak sense of a named suspect in that central park case, all of that has combined to bring the question of that case back now in light of this new case about bombs of so many different varieties. >> again, with -- from what we have now, what we know now, two separate incidents, completely two different devices, homemade devices, and a couple of months apart. we are always rethinking. this is still an open case. >> two separate incidents. completely, wholly different, a couple of months apart. it's an open case. maybe there is no connection, right? i mean, sometimes weird inexplicable stuff happens in the news, and it is just totally inexplicable, and it's just an outliar, but then sometimes months go by, and you think, oh, wow, that might not have been a completely isolated and inexplicable incident.

maybe that was chapter one in what has turned out to be a dramatic novel about a very experimental bomb maker. tonight as with so much else, we simply do not know. we will new this morning, a 48-hour manhunt ends with a police shoot-out. now we're learning new details about the man accused of planting several bombs in parts of new york and new jersey over the weekend. also this morning, donald trump's son is coming under fire after likening the syrian refugee crisis to a poisoned candy. welcome, welcome. lcome, thank you so much. it is great to have you here. let's talk about everything -- thank you so much for being here. >> you're so welcome. i am not contagious.