The Closer is a lady detective, chief of her agency, and based on Brenda Lee Johnson, the character of that title from the TV show of the same name. Unlike her counterpart, however, she is a closer in the literal sense. She enjoys slamming cases shut. As the staff in her office is getting ready to call it a day, she does a last minute inspection of all the cases in the room. She closes the pencil case belonging to Sergeant Gabriel, the case holding Lieutenant Tao's glasses, and Provenza's suitcase, the contents of which she has to dump out first. Each time she closes something, she says "case closed!' in a triumphant and matter-of-fact tone of voice. Then she demands to know who left the briefcase on the desk open, and is mildly embarassed when Gabriel has to point out to her that the case is hers. After this, she refuses to let her partners go home until the other office supplies have been closed as well. Provenza's jaw drops in surprise, and the closer threatens to close his mouth for him if he doesn't do so himself.
Just by coincidence, this character made her debut in same episode that Kyra Sedgwick, who plays her counterpart, appeared in the show's main storyline.