An episode of a crime drama?

I don't remember which crime drama it was but in the episode a white male in a suit and tie and glasses (kind of like Micheal Douglas in falling down) goes on a bit of a rampage with a shotgun that he has modified. I remember he shoots a lady after she cuts him off in a minivan and thinks about shooting a guy younger than him thats his boss at his office. He also gets pushed around by his kids and wife.