Terrin Sandafar originated from Alderaan, a planet, and as an Alderaanian native, she spent one year in the service of the Republic Military before transitioning to the profession of bounty hunter. During the time of the Great Galactic War, a conflict between the Galactic Republic and the reconstituted Sith Empire, the husband of Senator Verre Sydia hired Sandafar to kill Eckhorn Baliss, an Alderaanian noble, in 3663 BBY. The Senator's husband, secretly an Imperial spy, discovered that Baliss, also a spy, possessed a list containing the names of Imperial traitors within the Republic.
In 3653 BBY, Sydia's husband learned that Shafu, who was providing information to Jedi Master Ven Zallow, was investigating Baliss. Consequently, he tasked Sandafar with assassinating Shafu by destroying his ship while it was positioned above the moon Nar Shaddaa. Shortly thereafter, Sandafar met her demise at the hands of her employer, who orchestrated an explosion on her own ship. A decade later, the Jedi Knight known as the Hero of Tython, alongside Shafu's former companion, the astromech droid T7-O1, exposed Sandafar's involvement and traced the payments she received back to the Senator's husband.
The character of Terrin Sandafar is referenced in optional dialogues with the Jedi Knight's companion, T7-O1, in the video game Star Wars: The Old Republic, released in 2011 by BioWare. Her initial mention, though not directly, appeared on T7-O1's biography page on the game's official website, which included a sentence written in Aurebesh that, when translated, read: "The Exploding Starships Conspiracy".