I was on a mini-vacation this time last year in Boston. Girlfriend and I went to go on a tour of Fenway, and they were filiming scenes for this movie right next to the ballpark. They had roads cut off and about a zillion trucks and people. Looked like they were filimg a scene of police officers or FBI agents in a gun battle.
As we did the tour, we heard some fake shots and were told that was part of the filming. Also saw them tow an ambulance away that had "bullet holes" in the windshield.
As we were walking up some ramps we were told we could look down and watch them film a little, though we were not allowed to take pictures. Saw them film a sequence of a guy in a federal-looking outfit walking around.
Pretty cool. Can't wait to see it and see if I can connect up what we saw with parts of the film.