Transcript for Marathon Photographer Captures Images of Horror

Jon -- MacKey photographer from the Boston Globe he was a first hand witness to the aftermath his photos really. Captured the chaos that was happening right there on the ground at the finish line. John thank you for being with us today you are obviously in experienced photographer you have. Won many awards -- been in the business for thirty years and you've seen a lot of things but I can imagine nothing like yesterday. That's correct. I'm nothing can compare to what I thought it it was it was just incredible to -- The that the chaos that it will body's blood. From legs blown off people in agony. And I just hope there'd be that person again you know I was to be. Happy event we covered every year and -- never expect something like this push up. John. -- if you can't walk us through some of the photos that you captured yesterday and I imagine it must've been so difficult to. Be able to focus on what you've seen an -- and and try to process exactly how these events were playing now. -- let it happen I was at the finish line in the blast went off right going to be. One of the runners. Blacks to the grounds and I'm -- is helped. To his feet and it was very blunt complete opposite -- -- Just dumb look. And shock -- we have an old Patrick Arnaud. Looked around and -- wondering what was going on but I personally believe it was a explosion we -- -- communal over. And I was so close to be armed closed artery and this being an attorney but while the bodies. I didn't feel it first what to do I was I was thinking you know I didn't want people to leave the rest -- blanket. And I worked my way around -- -- in. What true multiplied. Baylor -- -- incredible scene of I mean held over a woman who was severely injured and he was would bring it here. Old English at. There was another near where -- -- -- His -- opinion that -- -- a bunch of debate -- -- there was this. You know it is a terrible being there is needed to be -- but I you -- And I don't want to the world being what was going on and that's my -- -- -- John act as your witness to this and as you are capturing those pictures have you had a moment yourself to reflect on the the impact. Of what you were witness to. Well on the way to do you know on policy -- propensity it was like a film warm. Back and -- -- -- of just being. You know -- inordinately happy memories while. I feel really not media to photograph. You know I'm there was nothing I really do I I -- so many viewers you didn't paramedics when it. I can't document it -- -- -- be just the cold. For everybody -- -- do. To do get over that there's going to be difficult for me at a Harlem I'm keeping with the with the High Court is that he. You know Mike Campbell being the I think it's just one of those things -- has -- Have you been back there since yesterday. We don't want. I don't know what to expect. Oriented and open to photograph the runner but he does themselves -- -- -- -- him. In he would put police in. Just wanted to you know go back and maybe she -- -- it is I don't I don't expect -- rejected those. And I'll just do my best we don't know what's behind -- And and -- -- said you're reaching out into this is different this is the picture that your refrigerator have you. Reached out to that runner. Our Priscilla -- -- he was doing okay he injured as Blake -- -- an Arctic you can walk -- shrapnel. These -- -- Boston right -- the impetus behind it and he. Is -- okay you know I'm just a beautiful thing later idea which is good to see him one out of -- happening with this in ammonium. From -- you know being in. Because there. Did he did he talk about the fact that when you actually see. The picture and then. Juxtapose that with the actual experience that there was some kind of disconnect that that he couldn't believe in fact that that was him. -- meeting of the -- but he talked about the experience but -- exposure. And he felt beyond the blast one knock them down and make natively -- Regis collapse the ground. And I think he was in shock wanted to do throwing arms. Comment has -- -- the police that -- they didn't know what they're expecting you know it is -- one. People -- being don't like use there's just and I think he was this the middle. He was being -- -- I sit on the finish line which was you know fifty feet away and he just plot straight for the emotional and. Was -- was her moment that you are concerned about your own safety just because of the sheer chaos that was happening in those quick moments. The the total to moments where it was when I was in the middle of all the people being helped -- -- police -- in these days. You gotta get out of here it but the another explosion. And -- -- okay I'm thinking myself but I shooting. Every it was running away. And the second moment was when I had to go about it might do which -- a unique photo page. And I have negotiated you know there's been -- photos -- -- -- the race. And I noticed that buffalo backpacks. Panic -- my I think you're. -- Is that a bomb -- right like. Product it is music good and it has on everybody to get out -- total bridge there was concern about other people think -- there. John thank thank you so much for being with us John -- active with the Boston Globe and capturing some of those raw and very powerful images. From yesterday.

This transcript has been automatically generated and may not be 100% accurate.