Emerson is a major antagonist in the Jack Reacher film.
He first appears in the movie investigating the murder caused by one of the movie's main antagonists, Charlie.
He finds James Barr and arrests him. But rather than answering the police, he instead writes a note telling the police to "GET JACK REACHER". Emerson takes Reacher to the hospital, and he finds Barr is lying in a coma. He asks Reacher why he would walk out on his own friend. Emerson later appears inspecting Sandy's corpse after she was killed by Charlie, and as he makes eye contact with Reacher, Reacher quickly drives off and a car chase ensues. Reacher eventually manages to escape the police by hiding in a bus.
When Emerson sees Helen again, he is revealed to be working for the Zec when he tasers her unconscious as she is heading off the elevator and takes her to the Zec's hideout. Reacher and an ex-Marine gunnery sergeant, Cash, attack the hideout. In the final shootout, most of the men are killed, Reacher kills Charlie in a fistfight, and Emerson is shot in the head by Reacher as he is holding Helen hostage.