Cahill, a Twi'lek male, held the rank of captain. His service occurred during the Cold War era, a period of tension between the Galactic Republic and the reconstituted Sith Empire.
Cahill's biography includes an event in 3643 BBY where he was on duty on the planet of Alderaan. During this time, he noticed Thul operatives moving substantial equipment toward an Organa weather monitoring station. Uncertain of the appropriate course of action, Cahill instructed a Republic spacer to proceed to Wardpost Hurne and relay the information to Captain Barra.