Sniffing For Bombs: Meet America's most elite dogs

The following script is from "Sniffing For Bombs" which aired on April 21, 2013 and was rebroadcast on July 21, 2013. Lara Logan is the correspondent. Max McClellan and Reuben Heyman-Kantor, producers.

When the bombs went off at the Boston Marathon this spring, highly trained dogs were rushed to the scene to search for more explosives. Boston police said dogs swept the streets in the morning and a second time just an hour before the first marathoners crossed the finish line. It's now known that the bombers planted their devices well after the dogs finished 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. And, as we first reported in April, 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 soldiers will 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.

Lara Logan: Do you think he enjoyed it?

Chris Corbin: He just wants to do whatever I'm doing, he doesn't care what it is.

Lara Logan: You've said that these dogs feel like they're invincible?

Chris Corbin: Absolutely.

Lara Logan: What makes you say that?

Chris Corbin: We don't train them to fail.

Sergeant First Class Corbin is a dog handler with 7th Special Forces Group and he and 6-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.

Chris Corbin: We walked in front. We cleared the pass for everyone to move through.

Lara 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?

Chris Corbin: You are the one risking, I hate to say 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.

Lara Logan: What's your level of trust in your dog?

Chris Corbin: It has to be this perfect trust.

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 FBI and police departments across the U.S.

Lara Logan: What can these dogs do on the streets of America?

Mike Ritland: The very same thing that they do for our boys overseas in that they detect explosives-- they are a fantastic deterrent-- they use their nose to find, you know, people as well.

Lara Logan: Would an average police dog have found these bombs at the Boston Marathon if they'd already been placed on the ground, you know, before they were sweeping through there?

Mike Ritland: There is a lot of variables that I'm not aware of as to where they were and what was done in terms of the sweeps. But based on what I do know, yes iif dogs went through the areas where they were placed-- you know, your average, certified police bomb dog should have found them. My thoughts are if these guys are paying close attention to these dogs, they're waiting. And when the dogs leave, they bring it in, they hand-- they infiltrate, essentially, they drop it right where it's busy, and very soon after, it detonates.

Mike Ritland knows from his own experience on the ground in Iraq what it means to have one of these elite dogs on your team.

Mike Ritland: When you step outside that wire--

Lara Logan: Like outside the base?

Mike Ritland: Outside the base. It's crossing the border to hell on Earth. Every step you take is that same feeling of, "The very next step that I take may be my last." When you see these dogs operate in the capacity that they can, using their nose and finding explosives in the manner that they do, the-- that level of comfort absolutely skyrockets in your mind, because you know that you've got one of the best-trained, best-equipped, best-capable, you know, working dogs out in front of you that has your back.

We met Mike Ritland on his 20-acre ranch in rural Cooper, Texas where he runs his own company.

Lara Logan: Tell me some of the things that these dogs can actually do. They jump out of planes? Helicopters?

Mike Ritland: You can free-fall with 'em. You can rappel with 'em. You can fast-rope with 'em. You can swim with 'em. I mean, they can ride on boats. They can ride on your back. There's not really an environment that we operate in that you can't bring a dog.

There's such a demand for them that Mike Ritland says they'd be used on almost every mission if there were enough of them. And it's not just about their nose. Ritland is training this dog, Rico, to track humans and take down enemy fighters.

He's three and a half years old and Ritland has been working with him for the past year. Here, he's about to apprehend a suspect. These dogs can run faster than 30 miles an hour.

The suspect is one of Mike Ritland's partners, and he's screaming to make this as realistic as possible. These dogs are trained to capture, not to kill.

Mike Ritland: There's no human being on Earth that can out run them. You know, I can tell you that the physical capability of these dogs is impossible to explain and even hard to comprehend when you see it.

Lara Logan: How hard can they bite?

Mike Ritland: Hard enough to break bones. I had a dog bite me, right here like this. He only had his mouth on me for probably four or five seconds and broke my wrist.

Lara Logan: He broke your wrist in four or five seconds?

Mike Ritland: Yeah, I mean just like that. Just broke it.

Mike Ritland says they have to teach these dogs how to deal with someone who wants to harm them. The trainer is putting pressure on him without hurting him. The aim is to make the dog comfortable, then teach him to ignore it, and by the end, Ritland says, the dog won't let it affect him at all.

Mike Ritland: The number one thing that I look for in a dog is that that dog, when pushed, and when he's put into an uncomfortable spot - where physically and mentally he's got pressure on him and I give him the choice, and it's absolutely a choice, to either stay and fight me or to quit and run, that dog decides I'm gonna stay and fight you. And I'm gonna beat you. When you do find that, it is a unicorn in that they almost don't exist.

Arko is one of those rare dogs. He's retired after repeated deployments to Iraq and Afghanistan and he now lives on Mike Ritland's ranch. Most of what he's done is classified, so Ritland could only tell us a little about the operation that almost killed him, when he took down an enemy fighter who shot him in the chest.

Mike Ritland: And, he maintained control of the guy, you know, after being shot, so--

Lara Logan: At point-blank range?

Mike Ritland: Uh-huh (affirm). Yep. So, you know, it's funny, because a lot of people, you know, I think scoff at the idea that, you know, what kind of things, what kind of obstacles can these dogs really go through? You know, and it's more than most humans.

For a dog to make it in the world of Special Operations, Mike Ritland says there are certain qualities that have to be there from the beginning.

Mike Ritland: He's already, you know, displaying the prey drive and possessiveness that we like to see in that he'll put uncomfortable objects in his mouth.

Most of the dogs that do this work well are from one breed: Belgian Malinois.

And there are only three places in the U.S. that breed them for top tier military units, like this one in West Virginia where Mike Ritland gets some of his dogs.

[Lara Logan: Oh they're so cute.]

Here, they specialize in the early stages of training, which starts almost from birth, with loud noises that are meant to get them used to the sounds they may one day face in combat.

Their noses are up to a 1,000 times more sensitive than a humans, and at just a few months old, they start learning to ignore other smells and distractions, while zeroing in on the scent of a bomb.

[Mike Ritland: So here she's trying to get her to be disobedient to that odor, and he won't do it.]

They'll repeat this training over and over for two years, so that by the time this dog goes to war or is needed on America's streets, nothing will take it off the track of a bomb.

Mike Ritland: Everybody knows that dogs can smell better than humans but what they don't realize is that if you and I walk into the kitchen and there's a pot of beef stew on the counter, you and I smell beef stew. A dog smells potatoes, carrots, beef, onion, celery, gravy, flour. They smell each and every individual component of everything that's in that beef stew. And they can separate everyone one of those. You can't hide anything from them. It won't work because you can't fool a dog's nose.

Dogs and their handlers work as a team, and they go through so much together their bond is as strong as a band of brothers. Green Beret Chris Corbin and Ax almost died together in Afghanistan on their final mission. Corbin says everything was going right that day, and Ax had already found one bomb. They moved together to an area that had been cleared and that's when he says he missed Ax's signal.

Chris Corbin: All of a sudden, he wasn't pulling forward, he was pulling down. I was, "What are you doing buddy? Hold still." I wasn't thinking it-- maybe he's sniffin my foot, maybe I passed by a dog-- all these other things why he would be looking down. And I looked down and he was just intently sniffing all around my foot. And it started to occur to me that..OK..

Lara Logan: Wait a minute.

Chris Corbin: With wires coming out of the building, we're already in a place that we know is full of mines, why is he sniffing down on my foot? And at that moment, it was just that, too little too late. And that was it.

Ax was shaken up by the blast, but not wounded. Chris Corbin lost both his lower legs. Yet in less than five months he was back on active duty as a Green Beret. He says Ax had a lot to do with it and described the moment he saw him again for the first time.

Chris Corbin: They brought him up for a visit. And I heard him, getting him out of the back of the truck. And opening his kennel, and he just being a stir-crazy dog, just, "Hey, let me out of here. Let's do a look around." I just said something simple. "Hey, where's my boy at?" and he stopped. He froze. He looked around. And he went into a panic until he found me and he jumped on my legs. Painful. Just-- I was just happy to see him. I didn't care how much it hurt.

During our entire interview, Ax never left Corbin's side and barely took his eyes off him. Corbin says he's fearless because he doesn't know when he's in danger.

Lara Logan: Some people might say, well, that's unfair to the dog because you're sending this dog into a dangerous environment where he could very easily lose his life or limbs, be wounded, and he doesn't understand.

Chris Corbin: I could make him scared of it and make him not do his job and send soldiers to the same death. That's my answer to that.

It wasn't until after 9/11 that Special Operations formally began using dogs, starting in Afghanistan. Duane and his dog, Rex, survived a tough deployment there in 2010.

Duane: I saw my dog, you know, trying to smash through doors, climb up cliffs, drag people down cliffs. Just track people, find odors that were hidden up in the ceiling-- just you name it. It seemed like, every day I was being amazed by these dogs.

Duane has been a covert operator for 21 years. He told us these dogs are so effective, they're now being targeted.

A Taliban commander told a member of our team that on his last operation they were ordered to open fire on the American dogs first, and deal with the soldiers next.

In Afghanistan, there have been 42 dogs killed in action and when they are wounded in combat they get the same care as any soldier.

And when these dogs retire from Special Operations, some of them like Rex, Duane's dog, find jobs with law enforcement. He's now working with the San Diego Sheriff's Department. Those who can't work anymore often end up with Mike Ritland, who's started the Warrior Dog Foundation to look after them.

Ritland is the first person to write a book about these elite dogs. He says when budgets are being cut, he hopes people won't forget how much a well-trained dog like Rico means on today's battlefield and on our city streets.

Lara Logan: And he's your dog?

Mike Ritland: Right now he is, yeah. That's always subject to change, but you know, he's better served serving our country than he is being my personal dog. So, you know, when the time comes for him to answer that call, I'd-- I'm always happy to see them go-- go do something for the greater good.