Dr. Nicole Keller

Dr. Nicole Keller is the main villainess from "Motherly Love," the 400th episode of Law & Order: SVU.

She was played by Sarah Wynter.

Dr. Nicole Keller is a psychiatrist who was divorced from her husband, Dr. Daniel Keller (also a psychiatrist), as well as the mother of their son, Luke Keller. Nicole is also a serial statutory rapist, as she engaged in a sexual relationship with student Ethan Miller, and later moved on to Luke's best friend, Trey Franklin. In the beginning of the episode, Luke arrived home and heard what he believed to be panicked screams from Nicole. After grabbing his father's hunting rifle, Luke found Nicole engaging in a sexual act, only for Nicole to scream that she was being raped. Luke shot and killed who he believed was Nicole's attacker, only to learn that it was Trey that he killed.

After Trey's murder, Nicole claimed to Olivia Benson that Trey came after her in her kitchen, and later forced himself on her on the kitchen counter. Later on, however, photos of Trey with Nicole were discovered, and when Olivia presented them to Nicole, the villainess claimed that Trey was obsessed with her, and that he broke into the house and took photos of himself with her while she was asleep; however, suspicion was falling on Nicole. After evidence of Trey's presence at the home was discovered (counteracting Nicole's claim that he was never upstairs), Olivia and Fin appeared at Nicole's office and arrested her, charging her with not only third-degree rape, but murder as well.

At her trial, Nicole stuck to her story during her testimony:  that she was raped by Trey and she cried for help when Luke appeared. However, when it seemed like she was about to be cornered, Nicole shockingly changed her defense; admitting that her relationship with Trey was consensual, but not only did Luke know about it, he was jealous of his best friend. Nicole claimed that Luke actually witnessed an earlier sexual encounter between them while he was in the doorway, stating that he was masturbating while doing so. She even stated that Luke had an oedipal crush on her, and blamed herself for Luke killing Trey. Despite the claims being false and his immunity, Luke actually considered pleading guilty for killing Trey.

After a conversation with Olivia, Luke testified against his mother, counteracting every one of her false claims. Nicole was convicted of second-degree murder and third-degree rape, and before she was led away, Nicole berated Olivia and accused her of believing that his own mother is the Devil.

Personality
As described by her ex-husband, Dr. Nicole Keller has a malignant narcisstic personality, She is also a manipulator with sociopathic tendencies, using her charms to get what she wants