• With: Robert Duffy

    This is a rush transcript from "On the Record," April 19, 2013. This copy may not be in its final form and may be updated.

    GRETA VAN SUSTEREN, FOX NEWS HOST: Tonight, the good news, he's captured. The Boston Marathon bombing suspect, as you know, is in police custody. And just a few moments ago, this picture came in to Fox News Channel. You can see the bloodied suspect in an ambulance. Police say the suspect has been hiding in a boat, that boat stored outside a Watertown home.

    Robert Duffy is the son of the homeowner. He joins us. Thank you for joining us, Robert.

    ROBERT DUFFY, STEPSON OF HOMEOWNER WHO FOUND TSARNAEV (Via Telephone): Hi. How are you?

    VAN SUSTEREN: All right, Robert, tell me exactly what happened.

    DUFFY: Well, speaking on behalf of the family, the most important thing is -- there was a period of time that we, the family, didn't know exactly what was transpiring. It was just like you had pointed out, there's so much information coming in.

    We actually were notified by a friend that there was a Franklin Street home on the television. Of course, I spun 180 degrees to the television to see, literally, my mother and my stepfather's home there with the boat that the suspect was found in.

    Immediate horror just swept through me. I broke down crying because we'd tried to call. The phone was busy for almost 30 straight minutes. We tried cellphones. Neither one of, you know, David nor my mother was picking the phone up. My sister was ecstatic. And we were -- you know, it was absolute horror because we were seeing the bullets, you know, gunfire erupt on Franklin Street, you know, as everything was unfolding.

    Finally, as I left my home to go to my father's house to see if I could find why no one was picking cellphones up or why we couldn't figure out where anybody was, my sister notified me that my mother had contacted her, and she and David were both safe. They had been evacuated after, you know, David had come across the suspect in the boat.

    And apparently, what had -- the actual what happened was, as soon as the ban on, you know, going outside, staying in the home was lifted, they kind of went out. My mother's health is ailing. That's why I'm kind of speaking on behalf of the family, to respect their privacy. They went out into the back yard for some fresh air on a beautiful Boston day finally, after a long winter. David walked around. The wind had picked up. The tarp on the boat, as you've described, had kind of lifted, which he found strange.

    He went over to the boat for a closer look. He found a strap that had been cut, not torn or worn through, it had been deliberately cut. He then was kind of stranged-out by the whole thing, noticed a small amount of, like, blood in this area. And then he took his little stepladder that he uses to enter and exit the boat. He went under the tarp, saw a small pool of blood immediately there, looked forward and because the tarp obscured a lot of sunlight -- it was gray and cloudy for a bit here -- he saw what he believed at the time to be a crumpled body, bloodied, in the front of the boat.

    Immediately panicked, he dropped off the ladder, called 911. With all of the SWAT and physical police presence right there in that neighborhood and street, they descended on them. They immediately evacuated them. That is why their cellphones were left behind. Whether or not they had the -- phone line had been cut or whatever, we don't know that. The phone line was busy. That's why we weren't able to find them for almost a 40-minute period.

    They are safe. That's most important thing. And most important thing now is that the suspect has been apprehended. You know, it's a shame that it had to unfurl in the back yard of my parents. But you know, nobody plans this. You know, it's not like a lottery ticket.

    VAN SUSTEREN: Well, it certainly is good news that your mother and stepfather are fine.

    DUFFY: Oh!

    VAN SUSTEREN: ... that he's in custody, and there was -- of course, there was a lot of applauding when it happened. Did your stepfather say anything to him in the boat, or did he make any say anything back to your stepfather?

    DUFFY: There has been -- there has been no communication between the two of us to, you know, verify what was said, if things were said, what took place. Knowing my stepfather very well and loving him for many years, he's a very quiet man in general. He's very -- you know, kept to himself.

    He probably just -- and again, this is assumption -- peeked his head up into his boat, his beloved prize, other than my mom, and saw the pool of blood. And again, with what's taken place all day via the media, 24 hours of nonstop, it just probably was one, two, three, he knew exactly what was going on.

    He dropped out of the boat, and his first instinct was 911, and that was it. Probably no conversation, knowing that gunshots had been fired, people had been shot up the street earlier in the morning, that an innocent police officer had been shot and killed for no reason, and unfortunate losses at the marathon finish line, just senseless, he probably just -- knowing him, he probably just dropped off the ladder and walked away for 911.

    VAN SUSTEREN: Robert, about how far was the shooting early this morning from your stepfather and your mother's home?

    DUFFY: Without walking the actual distance, it was less than three eighths of a mile.

    VAN SUSTEREN: Well, the good news is, of course, that they're fine.

    DUFFY: Yes.

    VAN SUSTEREN: And -- and he is in custody. Robert, thank you very much for joining us.

    DUFFY: Oh, thank you.