Jonkan was a Human male scientist who worked on the planet Coruscant during the Cold War with the Sith Empire. A member of the Republic superweapon initiative, a weapons development project, Jonkan was a member of the design team for the Planet Prison superweapon, but his superior, Doctor Tarnis, betrayed and killed the rest of the team before stealing the weapon. While Jonkan survived the attack by Tarnis, who was actually a Sith Lord, the mortally-wounded scientist managed to help a Jedi Knight track down Tarnis before his death.
Jonkan was fatally injured by Tarnis's attack.
A Human male, Jonkan worked as a scientist for the Republic superweapon initiative, the Galactic Republic's superweapon development project, and was part of the five-man research team for the Planet Prison weapon on the Republic capital of Coruscant during the Cold War with the Sith Empire. In 3643 BBY, Jonkan's superior, Doctor Eli Tarnis, told the researchers that the Jedi were planning on shutting down the project, and Tarnis convinced his subordinates to bring him the prototype deep in the territory of the paramilitary Justicars' Brigade.
However, once they arrived, Tarnis revealed himself to be a Sith Lord and brutally murdered the researchers before escaping with the prototype. Jonkan was the only one still alive when a Jedi Knight and the Padawan Kira Carsen arrived, and Jonkan struggled to tell the Jedi everything that had happened. When the Knight offered to take the scientist to a medcenter, Jonkan refused, saying there was no time, and told the Jedi to track the Planet Prison by its heat signature. Since the weapon needed time to build up power, Jonkan urged the pair to destroy the weapon and save Coruscant. Thanks to Jonkan, the Knight was able to locate Tarnis and the weapon in the ruins of the Jedi Temple.
Dark-skinned with brown eyes, Jonkan had gray hair by the time of the Cold War. The man was an intelligent scientist, but he trusted his superior, Tarnis, enough to believe that the Jedi would shut down the Planet Prison project. While dying, Jonkan felt that the safety of Coruscant and the Republic was more important than his own life, and he used his last moments to help the Jedi find the stolen weapon.
Jonkan first appeared in Star Wars: The Old Republic, a video game released by BioWare and LucasArts in 2011, during the Jedi Knight-class mission "Tracking Down the Traitor." Jonkan starts the next mission in the storyline, "Race to the Ruins," by informing the player how to locate Tarnis.