The Telos Security Force, often referred to as TSF, managed Telos's planetary security before the destruction of the planet's surface during the Jedi Civil War.
A TSF officer in full uniform
At the beginning of the Dark Wars, the TSF, now headquartered on the newly built, Citadel Station was charged with protecting the efforts of the Telosian Restoration Project on Telos IV. However, it was often ineffective due to infiltration of the Telosian Council—the acting government over Citadel Station—by Czerka Corporation officials, and the influence that corrupt organizations such as Czerka and the Exchange held over Citadel Station.
When the Jedi Exile arrived on Citadel Station aboard the Ebon Hawk in 3951 BBY, the TSF arrested her and her companions Atton Rand and Kreia for their supposed involvement in the destruction of the Peragus Mining Facility and failed to prevent her ship and droid, T3-M4, from being stolen by Brianna, a Handmaiden of Atris. Despite this inauspicious beginning, the Exile helped the TSF locate a missing man named Batono, uncover the origins of a bounty hunter who had infiltrated the ranks of the TSF, find two criminals who had escaped from TSF headquarters, and stop a smuggling ring on the station led by Samhan Dobo.
The TSF would later defend Citadel Station from Darth Nihilus during the Battle of Telos IV, fighting alongside Canderous Ordo's Mandalorians, Onderon Royalist soldiers from Queen Talia, Khoonda Militia soldiers from Dantooine, as well as the Jedi Exile and her companions.
During the Exile's stay, members of the TSF included Lieutenant Dol Grenn, Lieutenant Yima, Officer Soka Linu, and Officer Batu Rem.
Thousands of years later, the TSF would participate in the Telosian Civil War, fighting on the side of their government and the Telosian governor, Crion and his son, Xanatos against the Telosian population and the Jedi.
The TSF had a larger role in Obsidian Entertainment's original vision of Star Wars: Knights of the Old Republic II: The Sith Lords. Lieutenant Yima would give the player character—known as the Jedi Exile—a quest to expose the corruption of her fellow TSF lieutenant Atallo, who was covering up the illegal Czerka weapons trade on Citadel Station. However, this quest was later cut, and neither Yima nor Atallo appear in the final version of the game—although Yima is mentioned by Lieutenant Dol Grenn as investigating the Batu Rem impostor incident.
- Knights of the Old Republic Campaign Guide