Dr. Nicole Keller is a psychiatrist and statutory rapist who manipulated her teenage son Luke into killing her underage lover, Trey Franklin.
History
Beneath her polished, professional façade, Nicole was a deviant who had a sexual preference for teenage boys. As mentioned by her ex-husband, Nicole was very pretentious and lacking empathy or compassion. She also believed she deserves praise and admiration but at the same time is emotionally fragile. At some point, Nicole entered into relationships with Ethan Miller and later Trey Franklin, two of her son Luke's classmates and friends. When she was in the middle of having sex with Trey, Luke returned home and caught them in the act. To escape being exposed as a statutory rapist, she yelled to Luke that Trey was raping her. Luke shot and killed Trey to defend her.
At first, the detectives believe her story until they discover nude selfies exchanged between her and Trey. She is arrested and taken to trial, where she continues to claim she was raped. When she senses that the jury does not believe her, she creates reasonable doubt by saying that Luke killed Trey because he had sexual feelings for her, aiming to let her son take the fall. Realizing this after being convinced by Benson, Luke decides to testify against her one last time. Nicole is found guilty of murder in the second degree and rape of a minor in the third degree, and is sentenced to life in prison. As Luke is led outside the courtroom by his father, Nicole loudly says that she loves and forgives him, and states that she’ll always be his mother, but Luke ignores her. Before being taken away, Nicole sarcastically congratulates Benson for turning Luke against her, but Benson reminds her that she did that to herself. (SVU: "Motherly Love")