Emily Sullivan is a high school mean girl and primary harasser of Agnes Linsky. Her friend in the clique, Brittany O'Malley, had her sleep with Lukas Ian Croft, O'Malley's older boyfriend, so Croft could prove his devotion.
When the girls were arguing about their popularity, activities, and who held what position in the clique, O'Malley threw Sullivan into the trunk of her own car and drove around with the other girls, Andrea Kent and Paige Summerbee, periodically torturing her by burning her with cigarettes and stabbing her with manicure scissors. It was all in sadistic pleasure at first, but O'Malley started stabbing Sullivan with a knife, then left her and the car behind with the other girls, who took her accessories with them.
The girls were all arrested and imprisoned, as well as Linsky when she shot yet another student harassing her. (SVU: "Mean")