Amherst, N.Y. - "It had to happen, thank God it didn't happen in 12 years, but here it is it's happened so I guess it was kind of inevitable."
Those are the thoughts of Steve MacMartin, who spent 31 years in Homeland Security and Customs enforcement in Buffalo before retiring 2 years ago.
MacMartin believes this is probably an act of domestic terrorism, perhaps from a so-called lone wolf. One reason: if it were a large group or an international one, the bombing and the way it was carried out would likely have been much intricate, and would have killed and maimed many more people.
Another reason why MacMartin believes this is done by an American: the date on which it took place.
Steve MacMartin: "Patriots' Day in Massachusetts and then the target of opportunity being the marathon. Which kind of leads you to it being domestic or a local group with a small agenda. Again this is just my personal opinion, but I think it's going to be somebody from the local Boston area."
Scott Brown: "Are they going to go through and catalogue every tiny bit of debris that's at the site?"
Steve MacMartin: "The techniques being used won't be much different from any criminal investigation, they will certainly for days be cataloguing every piece of evidence they can find. I participated in the World Trade Center recovery effort and I know evidence was being catalogued months into that recovery."
In terms of how the bombs were planted, MacMartin believes there was a last security sweep about an hour before the first finishers, leaving the bomber a window of about three hours to place the bombs.
Scott Brown: "Is is surprising with the police presence there and the cameras that no one noticed anything?"
Steve MacMartin: "The first thing is no, it's not surprising. Remember where the trash cans were, back against buildings. Everyone's attention was focused on the street, away from where those trash cans were, somebody walking through a crowd and stopping and dropping something in a trash can probably would have gone unnoticed."