Jodie Foster movie

There is a reference in the movie to another movie involving Jodie Foster where a guy keeps his anger bottled up which one day bursts up making him kill everyone in his office with a gun (an AK-47 according to this movie).
Can anyone be kind enough to tell which movie is it, though I know another movie with similar outline, He Was A Quite Man, which was released after this movie (in 2007) and starred Elisha Cuthbert, so it cant be that movie. I have racked my brains and searched the net for an answer but to no avail. So any help will be highly appreciated.