During the Cardassian Occupation of Bajor, Trentin was an informer for the Bajoran Resistance, though she was never officially a member. She worked as a cleaner at a Cardassian records office in Dahkur Province, from which she secretly passed information to the Shakaar resistance cell for years without being discovered. The information she provided allowed the Shakaar cell to mount dozens of attacks on Cardassian targets. She never stopped helping the Resistance, but spent every day terrified that she would be caught and executed by the Cardassians. Her fear was so great that, even after the Occupation ended, she did not want what she had done to become known.
Trentin was murdered in 2373 by Silaran Prin, as part of a campaign of killings that Prin perpetrated in revenge for his being maimed during the Shakaar cell's assassination of Gul Pirak. When members of the Shakaar resistance group were being hunted down and killed, Trentin feared for her life and contacted Kira for help. Kira assured her that she would help and as such arranged for Trentin to stay on the station for her protection until the crisis had passed. Kira subsequently ordered Dax and Worf, who were returning to the station from another mission to make a stop en route back to the station and pick up Trentin. Unfortunately, Prin used a hunter probe to plant a remat detonator on Trentin without her knowledge, which fatally disrupted her rematerialization as she transported to a runabout that was to take her to Deep Space 9 for protection. When Kira found out about this she grieved for her friend and said a silent prayer over her friend's remains that were left on the transporter pad. Prin regarded Trentin as guilty because her information had allowed the Shakaar cell to bypass the security systems of the Cardassian weapons depot outside Hathon where Pirak was stationed, enabling their attack. (DS9: "The Darkness and the Light")