A Starfleet engineering ensign whose remains are found in a power conduit on Deep Space 9 in 2369, the victim of a murder that leads to an assassination plot against Vedek Bareil.
Ensign Aquino is a Starfleet engineer whose death drives part of the first-season Deep Space Nine finale In the Hands of the Prophets. O'Brien, searching for a missing tool, finds what is left of him in a plasma conduit, where the body appears to have been caught in an accident.
Bashir establishes that Aquino was killed by a phaser before he was placed there. Odo and O'Brien learn that he had gone to investigate a security anomaly at a runabout pad during the night and had surprised someone tampering with the systems.
The killer proves to be O'Brien's Bajoran assistant Neela, who was preparing an escape route for her attempt on Bareil's life.