Monk, Natalie and Sharona drive to Los Angeles, arriving by nightfall. They meet Lieutenant Sam Dozier of the Los Angeles Police Department while he's investigating the shooting of a cashier killed in an antiques store robbery. Here, Monk (wearing a gas mask due to fear of the smog) exposes the owner's wife as the killer. They then travel to Ellen Cole's house. Monk examines the scene and concludes (somewhat to his own regret), that Trevor is innocent. He notices several clues that suggest that Ellen Cole's killer was waiting for her, meaning that the murder was premeditated. However, Dozier informs Monk that jewelry from Trevor's clients was found in his truck, and Sharona dismisses this as not being enough to arrest Trevor - after all, it's not too difficult to commit identity theft and open an account with someone else's name to fence stolen goods.