Jackie Blaine is a transgender woman and the prime suspect in the beating and muilation of Mark Van Kuren.
Jackie was born as Harold Franklin, but she always believed she was actually a girl. In the past, there were no resources for a sex reassignment surgery and she was forced to live with being a male for three years after her realization. During that time, she was attacked by three men aware of her gender identity, calling her a freak and castrating her.
After having the surgery, Jackie became a school counselor and eventually came across Hailey Van Kuren, a thirteen-year-old transgender girl whose life was made miserable by her father Mark, who continued to believe she was a boy. Realizing that Hailey was extremely suicidal and wanted her father dead, Jackie empathized with her. She was eventually driven to brutally attack Mark as he was coming out of a strip club. She was arrested after Detectives Benson and Stabler realized she knew about Mark being present at the strip club, which they never disclosed to her.