Thrax Vols was a Yarkora scientist who specialized in biological warfare. He allied himself to the Confederacy of Independent Systems in the Clone Wars, but defected after he saw how poorly the CIS was doing against the Galactic Republic. Thrax then set up a private prison in 0 ABY. In 13 ABY a riot was orginised in his prison, prompting Thrax to give the order to kill every inmate in the prison. Before he killed every one of his prisoners, Lydia Bale hung him in his office.