The movie is set in 2008, as evidenced by political ads, but a late model (2009 or later) white Mazda sedan can be seen on the street in one of the scenes.
When Jackie shoots Trrattman with a pistol through the car window, the ejected shell casing from the pistol is clearly that of a blank, as can be seen by the crimped end of the cartridge casing.
At one point in the movie Frankie mentions a bar in Haverhill. He pronounces it "haver-hill" but anyone living in new England know it is pronounced "have-rill".