Gardaí have completed their inquiries into the murder almost 22 years ago of trainee school teacher Deirdre Jacob and have submitted a file to the Director of Public Prosecutions.
Investigating officers have recommended that a murder charge should arise from the outcome of their inquiries, which focused on a small number of suspects in the past few years.
They included the main "person of interest", Larry Murphy, who served 10 years of a 15-year sentence after he was convicted in 2001 of abduction, rape and the attempted murder of a woman, who was found in the boot of his car in the Dublin Mountains.
Ms Jacob (18) was last seen crossing the road towards her home at Roseberry, Newbridge, Co Kildare, about 3pm on July 28, 1998.
Her disappearance was treated officially by gardaí as a missing persons case until August 2018, when it was formally upgraded to a murder investigation.
The decision to reclassify the case followed the emergence of new information, which led to gardaí opening up fresh lines of inquiry.
The name of one person in particular had been mentioned at previous case conferences but, until then, officers had been unable to unearth any firm evidence that potentially implicated him in the disappearance.
The additional information was regarded as substantial and solid enough by senior investigators - Chief Supt Brian Sutton, who was then in charge of the Kildare division, and Supt Martin Walker - to officially launch a murder investigation, with the assistance of members of the Garda's cold case unit.
But whether the information contained in the Garda file is sufficient to sustain a murder charge is a matter for lawyers in the office of the DPP.
Murphy became a person of interest after it emerged he had visited the shop owned by Ms Jacob's grandmother.
During an interview with gardaí while in prison, Murphy denied any involvement in her disappearance.