In 2369, Neela served on the space station Deep Space 9 as an engineer under Operations Chief Miles O'Brien. As part of her duties, she once helped to repair Lieutenant Jadzia Dax's science station following a malfunction. (DS9: "Duet")
Secretly a religious activist, she was placed on Deep Space 9 as a cover for her assassination attempt of Vedek Bareil Antos, ostensibly to ensure the succession of Vedek Winn after the death of Kai Opaka. She planted a bomb in the station's school to convince Bareil to visit the station and killed Ensign Aquino after he caught her planning her escape route.
However, Commander Benjamin Sisko and Chief O'Brien managed to discover Neela's intentions and stopped her before she could kill Bareil. Neela was subsequently taken into custody, but refused to implicate Winn. (DS9: "In the Hands of the Prophets")
Background information Edit
Neela was played by actress Robin Christopher.
The script for "Duet" describes Neela as a Bajoran "engineering apprentice". It further gives the pronunciation of her name as "NEE-la".  In contrast, the script for "In the Hands of the Prophets" gives the pronunciation as "NEE-luh". She is also described as being, "in her early twenties, bright, pretty, and eager to please." 
Neela was originally supposed to appear in three episodes of the season, making her debut in "The Forsaken" with the aim of making the audience believe she was to be a new recurring character so as not to make it obvious she was the villain. Unfortunately, the producers decided that the actress playing Anara in that episode wasn't the right type to be an assassin and so the role was recast as Neela. A leftover reference to Anara can still be seen in the final episode in the form of the computer code O'Brien and Dax break, which spells out "A-N-A-R-A". (Star Trek: Deep Space Nine Companion, p. 66; The Making of Deep Space Nine, p. 302)