|Pathology|| Serial assailant|
|Family|| Unnamed father (deceased)|
Grace Mayberry (mother; deceased)
Jason Thaddeus Mayberry is a rapist and murderer who suffers from piquerism.
Jason was raised by his mother, wealthy socialite Grace Mayberry, after his father died when he was five. His mother began molesting him when he was six, and coerced him into an incestuous relationship when he reached puberty. Jason remained his mother's primary sexual partner until he became an adult. As a result of his mother's sexual abuse, he grew up to hate women, and developed piquerism as well. He began stabbing dozens of women in the legs, back, and buttocks with hatpins, which he kept as trophies. He tried to become a police officer, but was rejected by the police academy after failing the psychiatric exam. He began working as a security guard at a software company, and became obsessed with a coworker, Veronica Tandy. At first, she tried to help him by writing a letter of recommendation for his police academy application. However, she withdrew the letter when he began harassing her. Enraged, Jason raped, strangled, and stabbed her to death.
Investigating, Detectives Benson and Stabler bring Jason in for questioning after learning from their coworkers that he had been bothering Tandy. On advice from Dr. George Huang, Stabler gets Jason to open up by pretending to hate women as well. Jason tells several conflicting stories: that he and Tandy were just friends, that she was sexually harassing him, and then that she was going to leave her husband to be with him. Meanwhile, Benson learns that Jason had been stalking Tandy, taking pictures of her without her knowledge and telling people she was his girlfriend. She also talks to Grace and learns about the abuse Jason suffered as a child.
When Stabler confronts him about what his mother did to him, Jason breaks down and confesses to killing Tandy. Grace Mayberry herself was also found out for her crimes of pedophilia and sexual abuse on her son. However, Jason's lawyer argues that the search was illegal, which jeopardizes the case. His mother posts his bail, and he goes home. When the detectives arrive there with a search warrant, hoping to find the murder weapon and arrest Grace for the murders, they find Jason in bed with his mother, naked and covered in her blood, having stabbed her to death while having sex with her. (SVU: "Pique")
- Unknown dates:
- Houston, Texas: Unnamed woman (assaulted; was stabbed in the buttocks and back with a hatpin)
- Norfolk, Virginia: Unnamed woman (assaulted; was stabbed in the buttocks and back with a hatpin)
- New York City, New York: Six unnamed women (assaulted; all were stabbed in the buttocks and back with hatpins)
- April 24: Veronica Tandy (choked out, raped from behind, and stabbed to death)
- April 30: Grace Mayberry (his mother; stabbed to death)