Tammy was a transgender prostitute who was hired by a publishing company to pose as Bobby O'Rourke, the unseen author of an autobiography recounting his trauma from past sexual abuse and his life on the streets, after producers approached the company with an offer to option the book into a film.
Tammy was later found murdered behind an alley from being repeatedly beaten with a brick after a reading event wrapped up. SVU received the case due to suspicions of a hate crime when her pre-op anatomy was found out. Tammy's killer, Will Glover, was eventually apprehended and confessed; he revealed that he solicited Tammy for sex for weeks, then killed her in a rage upon finding out she was transsexual.
Tammy's true identity and the circumstances behind her employment were eventually revealed after Detective Carisi decided to look into the publishing company's claims further. Bobby O'Rourke was later revealed to be a pseudonym for the book's real author, Benjamin Edelman, a recluse who wrote about his childhood sexual abuse as his personal therapy; the pseudonym was lifted from a bartender who died forty years earlier. (SVU: "Alta Kockers")