Deirdre was last seen about 3pm on 28 July 1998. She had gone to the Newbridge branch of Allied Irish Banks to get a bank draft to pay for student accommodation at the university, then went to the post office to post the bank draft. She also visited her grandmother, who owned a shop. The last sighting of her was close to her house on Barretstown Road. At the time of her disappearance she wore a dark T-shirt with white shoes and was carrying a black bag with a yellow Caterpillar Inc logo. The bag has never been found.
Aftermath
Deirdre's parents have never been able to move on and still hope that someone with information on their daughter's disappearance will come forward. They have appealed to the public for information several times over the years. In 2016 her parents said that there was not as strong a link between their daughter's disappearance and convicted rapist Larry Murphy as was often supposed. Gardai were never able to place Murphy in Newbridge the day she disappeared. The only connection found was a piece of paper with Larry Murphy's name and phone number among the belongings of Deirdre's maternal grandmother after the latter's death. She had owned a shop in Newbridge and Murphy had left his contact details with her grandmother as he was making wooden children's toys, but this was years before Deirdre's disappearance. In July 2018, on the 20th anniversary of her disappearance, her father called for a dedicated missing-persons unit to be set up. Her parents were satisfied that the Gardai in Kildare were doing everything possible to locate their daughter, but that a dedicated unit would help investigations into missing persons cases. By 2018 Gardai had conducted 3,200 lines of inquiry and taken 2,500 witness statements.
The case was reclassified as murder because of new information and a review of the case. Although Gardai did not reveal the new information, they said there was a definite line of inquiry. In October 2018 Gardai stated that they had 'significant' new leads in the murder probe and identified Larry Murphy as 'a person of interest'. Her family still live in Newbridge and although they knew the reclassification of her disappearance as murder was to happen they still found it heart-wrenching and shattering to hear the language of a murder investigation used about their daughter's disappearance.
