working dog. and ever since 9/11, dogs are being used more and more. what can these dogs do on the streets of america? >> the very same thing that they do for our boys overseas. they detect explosives. they are a fantastic deterrent. >> mike ritland knows ab dogs. he trains some of america's finest and gave us a rare glimpse inside the secretive world of the most elite dogs. >> at times like these with the bombs in boston, many of us can't help but be drawn back to the horrific events of september 11th, 2001. about a year from now, at ground zero in new york city, one of the largest and most ambitious memorial museums in the world is scheduled to open its doors. >> just watch your step, leslie. it is a construction site. >> tonight we'll take you for a first in-depth look at what our nation's 9/11 museum will be. >> i'm steve kroft. >> i'm lesley stahl. >> i'm morley safer. >> i'm bob simon. >> i'm lara logan. >> i'm scott pelley. those stories tonight on "60 minutes." >> cbs money watch update sponsored by: >> . >> glor: good evening. federal budget cuts hit the f.a.a. today with air traffic controllers told to stay home one day every two weeks. apple reports earnings tuesday amid increasing investor concern. the stock is off 40% since september. and gas prices at $3.51 a gallon are down 17 cents in a month. i'm jeff glor, cbs news. [ woman ] i take one prevacid 24 hr for frequent heartburn and coffee is coffee, a quick bite is a quick bite, and play time is play time, because for 24 hours my heartburn is lights out. prevent acid for 24 hours with prevacid 24 hour. introducing bbm video with screen share. hey aleigh. hey! carol! update on 171 woodward..... let's other people see what's on your screen. and these are the material studies. the dog was my suggestion. aleigh. aleigh! it's great. but i'm on vacation for another week, remember? oh, right! i'll call you tomorrow! ok. but don't. carol? the blackberry z10 with screen share. powerful communication on the powerful network. verizon. >> pelley: a five-day battle in the war on terror leaves us with a lot of questions. what was the motive for the marathon attack? where did the terrorists plan to strike next with their arsenal of bombs? and how did the manhunt stop them in only a little over 100 hours? tonight, we have the inside story from one of the leaders of that hunt, boston police commissioner ed davis. last monday afternoon, davis was in the stands at the finish line. all was going well, so he left to take a call. one of the city's favorite celebrations was coming to an end. the marathon is alwayse on th day that marks the start of the american revolution, but suddenly ed davis and a task force of more than 4,000 would find themselves defending boston on patriot's day. ( explosion ) when you arrived, what did you see? >> davis: i saw a bombing incident that i'd only seen in places overseas. i saw officer michael barrett from the boston police department wade into an unbelievable scene of carnage and put the fire out on an individual that was still on fire, and then grab belts off people and put tourniquets on the man's legs so he could save his life. >> pelley: this is your city. you're enormously proud of it. and these people had done this on patriot's day. >> davis: itertainly made me resolve to find these people quickly and to hold them accountable. >> pelley: you were going to get them. >> davis: yeah, i was. >> pelley: you made that promise to yourself. >> davis: i did. and to several other people, too. >> pelley: ed davis' promise was to the three who were killed and more than 170 wounded. the first calls he made were to richard deslaurier, head of the f.b.i.'s boston office, and colonel timothy alben of the state police. the f.b.i. took the lead and the marathon became a sprint. >> davis: very quickly, we established a command post at the westin hotel in the ballroom. and that expanded from about a dozen people when i first walked in the door to 100 people in the first hour. >> pelley: they found bomb parts right away. evidence cascaded in. >> davis: it's a logistical nightmare. we found very quickly that we needed a place to process this evidence, so a warehouse was obtained. very quickly, computers were brought in from the f.b.i. and the state police and the boston police and set up to review video. >> pelley: among the thousands of faces, they wanted to isolate people who didn't seem surprised. >> davis: and particularly one of the f.b.i. agents who's a technical expert did a tremendous job and really was the person that was able to get to the bottom of this very quickly. >> pelley: look at these people running in terror, but look deeper and see what the agent saw. this kid seems unconcerned. turned out, he came with a backpack but he left without it, just like the older man who seemed to be with him. and when you saw the faces of those two men, you thought what? >> davis: i thought about the death of the eight-year-old boy, the martin child, and how someonwho di't appear to be particularly el do such an evil thing. >> pelley: they didn't appear all that evil to you in the video? >> davis: no, they looked like college kids. >> pelley: 19-year-old dzhohkar tsarnaev and his 26-year-old brother tamerlan were from a region of russia that's mostly islamic. their ancestors were from chechnya, where islamic militants have fought a vicious civil war against russian rule. around 2002, the family fled as refugees to the united states. >> rose schurtzberg: i can't give you a specific moment when i first met him. he just sort of appeared in my life. >> pelley: rose schootzberg knew dzhohkar at cambridge rindge and latin, a top high school where dzhohkar did well. you told us at one point that you had in high school a little bit of a crush on him. >> schurtzberg: i yes, i did. how could you not? >> pelley: what was it about him? >> schurtzberg: i think it was that he was equally smart but also humble and, you know, incredibly funny. like, he was he was just an all around wholesome and good person. >> pelley: he fit right in. in 2012, he became a citizen, swearing the oath to protect the united states from enemies foreign and domestic. did he seem overtly religious to you in any way? >> ahmad nassri: not even a little bit. >> pelley: not even a little bit. these friends saw him two weeks ago. he was a sophomore at the university of massachusetts, dartmouth. ahmad nassri and bassel nasri tried without luck to get him to join the m.s.a., the muslim student association. did you see him at mosque? you see him at prayers? nothing like that? >> group: no. >> bassel nasri: no, unfortunately. >> pelley: unfortunately? >> bassel nasri: i would've loved for him to come to the m.s.a. a few times so he can maybe understand his religion better. maybe that would... that would've helped in what happened, i would say. >> pelley: what was he interested in? >> group: soccer. cars. >> ahmad nasri: if someone a few days ago told me that one of my friends was responsible for the bombs, bombing in boston, i would've named off at least 90% of everyone that i know before i would've said dzhohkar. >> pelley: tamerlan tsarnaev did not fit in easily. a champion amateur boxer, he was disappointed that he couldn't try for the u.s. olympic team because he wasn't a citizen. he lived with his wife and child in this cambridge house, divided into three apartments. al ammon lives there, too, and he says he and tamerlan argued three months ago. >> ammon: he was explaining how the bible is a cheap copy of the koran and how it's used for the american government as an excuse to invade other countries. and i remember he said that america's a colonial power, trying to colonize the middle east and africa. and he also said that the most casualties in afghanistan and iraq are innocent bystanders gunned down by american soldiers. >> pelley: did he seem angry about all of this? >> ammon: he seemed more passionate about it. he was... >> pelley: passionate about it? >> ammon: yes, yes. he strongly believed what he said. there was tension between both of us. it was more of a really involved discussion. >> pelley: "strong beliefs" was exactly what russian intelligence told the f.b.i. about tamerlan. two years ago, the russians asked the f.b.i. to look into whether he was involved in militant islam. f.b.i. agents interviewed tamerlan and decided he wasn't a threat. still, his pending application for citizenship was held up because a background check turned up that 2011 f.b.i. investigation. the f.b.i. is now looking into why tamerlan returned to russia recently for about six months. last thursday, when it released the tape, the f.b.i. knew him only as "subject number one," with subject number two following in his footsteps. it was only five or six hours after the videotape was released that events began to unfold rapidly and there was a great deal more violence. >> davis: it's possible that these individuals activated themselves once again because they saw the pictures, because they knew that we would eventually find out who they are. >> pelley: by 10:15 thursday night, officer sean collier was ambushed and murdered in his cruiser. then, gunmen hijacked a car which was spotted by a lone watertown officer. >> davis: at that point, the vehicle stopped. the two suspects alighted from the area of the vehicle and opened fire on the officer. ( gunfire ) very quickly another officer, richard donohue from the m.b.t.a. police, arrived at the at the scene and also engaged in gun battle. he was shot and grievously wounded. >> police radio: loud explosions, loud explosions, loud explosions! >> davis: the suspects began to log devices at the police, and the first one was a huge explosion. and then the follow-up explions we smaller. but they were improvised hand grenades were being thrown at the officers. >> pelley: the big explosion was a bomb like the ones at the marathon. parts of it were embedded in the patrol cars. the grenades were packed with steel pellets just like the marathon bombs. ( rapid gunfire ) >> davis: the gun battle continued until on the suspects ranutmunion anone of the sergeants tackled him to the ground. pelley: a police officer ran out and tackled him, these men who had armed themselves with so many explosives? >> davis: that's correct. that's what happened. it probably would not be advised as a tactical move, but it shows the courage and commitment that officers have in attempting to get this thing under control. >> pelley: he was going to put the guy down before he had a chance to reload, and risk his own life to do it. >> davis: right. he saw an opportunity and he took it. >> pelley: tamerlan tsarnaev was down, dying from multiple gunshot wounds. the younger brother gets in the car, backs over his older brother, drives away. what happened then? >> davis: the suspect that fled abandoned the vehicle four blocks... four or five blocks away and took off on foot. we determined that a 20-block perimeter had to be set up. >> pelley: and so began the lockdown of the city of boston. >> do not open the door unless there is a yiewrmd, identified law enforcement officer on the other side. >> pelley: the tsarnaev apartment was raided. they found bombs inside and wondered what plans the brothers had for those. the 20 block search lasted 15 hours, and then davis announced that they had lost the suspect. >> davis: there was extreme frustration and disappointment in the command post. >> pelley: and it was not, what, 30 minutes later... >> davis: it was probably close to 15 minutes later. >> pelley: that a man called 911. he went into his backyard where he has a boat with a cover over the top, and he saw the cover was torn. >> davis: right. he said he was dying for a cigarette. he had to go outside to have his cigarette, and he saw the blood on the boat. and so, he peered in after climbing a ladder. and he told me that he saw a body in there with blood on it. >> davis: a gunshot was heard and officers returned fire. the order was given to cease fire. we then pulled the state police helicopter in, which has a forward looking infrared device on its nose. and it was able to come in and actually look through the plastic on the boat and see the suspect inside. >> george macmasters: my thought when i first heard those 20 rounds was that he was already dead. >> pelley: neighbor george macmasters hrdt all from his home nearby. >> macmasters: the thought that he'd been killed, just to me is, you know, one more tragedy because the last pictures i saw, he's an older face, and that's not the face i remember. >> pelley: macmasters had once hired dzhohkar as a 16-year-old lifeguard. if dzhohkar is the bomber, macmasters has a question. >> macmasters: "how in the world did this happen?" you know, how could he have been changed so much in the year, year and a half that i've been absent; go from a young man that... polite, well-spoken, friendly, engaging, typical american teenager to what i have to say is a monster? >> pelley: his question is one of the mysteries. though his friends didn't see it, we know dzhohkar was failing in college. something had changed. an f.b.i. negotiator talked him out of the boat. he had been shot in the leg the night before. >> s.in custody. no one is to enter the perimeter. >> pelley: they treated him for a gunshot wound through the mouth that exited the back of his neck. whether that was a suicide attempt, davis won't say. do you think he's going to pull through? >> davis: i wouldn't comment. >> pelley: but the wounds are serious enough that there's a chance that he might not? >> davis: they're very serious wounds. ( cheers and applause ) >> pelley: on saturday, at fenway, the red sox honored the innocent people who were lost and wounded and the army of 4,000 who were part of the investigation. in boston, of course, this is a great honor; the red sox are the second oldest sporting institution in the city after the boston marathon. ( cheers and applause ) [ phil ] when you have joint pain and stiffness... accomplishing even little things can become major victories. i'm phil mickelson, pro golfer. when i was diagnosed with psoriatic arthritis, my rheumatologist prescribed enbrel for my pain and stiffness, and to help stop joint damage. 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[ doctor ] enbrel, the number one biologic medicine vo:building castles, -imagine oceans, and lagoons in the place we call home. bold is where everyone comes to play. starting our day off with a good dance and singing us to sleep at night. coloring our lives in ways only bold can do. it's no wonder bold will make your reality, a dream. if you've got it, yoknow how hard it can be to breathe and man, you know how that feels. copd includes emphysema and chronic bronchitis. spiriva is a once-daily inhaled copd maintenance treatment that helps open my obstructed airways for a full 24 hours. you know, spiriva helps me breathe easier. spiriva handihaler tiotropium bromide inhalation powder does not replace fast-acting inhalers for sudden symptoms. tell your doctor if you have kidney problems, glaucoma, trouble urinating, or an enlarged prostate. these may worsen with spiriva. discuss all medicines you take, even eye drops. stop taking spiriva and seek immediate medical help if your breathing suddenly worsens, your throat or tongue swells, you get hives, vision changes or eye pain, or problems passing urine. other side effects include dry mouth and constipation. nothing can reverse copd. spiriva helps me breathe better. does breathing with copd weigh you down? don't wait to ask your doctor about spiriva. >> logan: when the bombs went off at the boston marathon, highly trained dogs were rushed to the scene to search for more explosives. boston police have said dogs swept the streets in the morning and a second time just an hour before the first marathoners crossed the finish line. red ckely that the bombers planted their devices well after toged sweeping the area. since 9/11, dogs have been used more than ever because nothing has proven more effective against hidden bombs than the nose of a working dog. the best of them serve with u.s. special operations, and they're in a league of their own. it's nearly impossible to get anyone to talk about them publicly because much of what they do is classified, but we were able to talk to the people who train them for this story. we took the opportunity to ask about what might have happened in boston while getting a rare glimpse inside the secretive world of america's most elite dogs. green beret chris corbin and his dog, ax, are at 14,000 feet in the skies over north carolina. they're about to test a new harness that america's best iersill use to jump into combat. but it's not for corbin, it's for ax. as they free-fall for nearly 10,000 feet at 125 miles an hour, ax is wrapped in corbin's arms. they've been to war together, nearly died together, and they never like to be too far apart. do you think he enjoyed it? >> corbin: he just wants to do whatever i'm doing. he doesn't care what it is. >> logan: you've said that these dogs feel like they're invincible? >> corbin: absolutely. >> logan: what makes you say that? >> corbin: we don't train them to fail. >> logan: sergeant first-class corbin is a dog handler with 7th special forces group, and he and six-year old ax have been a team for three years. they deployed to helmand in southern afghanistan at a time when more americans were dying there than any other place in the country. corbin and ax's job was to lead their unit through a battlefield littered with hidden bombs. >> corbin: we walked in front. we cleared the pass for... for everyone to move through. >> logan: you say it so easily-- "i walked out front"-- like it's nothing, but what does that actually mean when you're the one walking out front? >> corbin: you are the one risking... i hate to s the most, but, yeah, you're out front. i'm the one who makes it safe or announces it as safe for everyone else to walk behind. >> logan: what's your level of trust in your dog? >> corbin: it has to be this perfect trust. >> logan: perfect trust that begins with trainers like former navy seal mike ritland. he's one of just a handful of people in this country who finds and trains these dogs for special operations and top tier units in the f.b.i. and police departments across the u.s. what can these dogs do on the streets of america? >> ritland: the... the very same thing that they do for... for our boys overseas, in that they... they detect explosives. they are a fantastic deterrent. they use their nose to find, you know, people as, well. >> logan: would an average police dog have found these bombs at the boston marathon if they'd already been placed on the ground, you theykn, ere sweeping through there? >> ritland: there is a lot variables at i'm not awaref as to where they were and what was done in terms of the sweeps. but, based on what i do know, yes, if... if dogs went through the areas where... where they were placed, you know, your... your average, certi