Axel: Because in police work, this is what's known as a clue. There's only two or three people who know how to do this kind of quality work. We'll show it around and see who recognizes it.
Rosewood: Great. Who are the two or three guys?
Axel: Fuck you asking me for? This is your town. You should know shit like that.
Axel waits for Rosewood and Taggart outside the station. He tells him why he took a shell casing from evidence.