The 18-year-old was last seen metres from the front gate of her parent’s home in Newbridge, Co Kildare on Tuesday, July 28, 1998, at approximately 3.30 pm.
She never made it back inside the house.
That day, Deirdre had popped into town to visit a bank, the post office, and her grandmother’s shop. She was captured on CCTV walking through the town carrying a black canvas bag with a yellow Caterpillar (CAT) logo.
When last seen she was also wearing a navy Nike jumper with a white collar, blue jeans and blue runners.
She was visiting her hometown from London, where she was studying in St Mary's Teacher Training College in Twickenham.
The student was due to return to the English capital the following week to start a job as a receptionist.
Just hours after her disappearance, the alarm was raised and searches began.
But little did Gardai, or her family know at the time, that she would become just the latest woman to be associated with Ireland’s so-called ‘Vanishing Triangle’.
The Vanishing Triangle is the name given to an area in the east of Ireland where six women; Annie McCarrick, JoJo Dullard, Fiona Pender, Ciara Breen, Fiona Sinnott, and Deirdre Jacobs, all vanished without a trace between 1993 and 1998.
Just months after Deirdre vanished in September ‘98, Gardai were stirred into action when Commissioner Pat Byrne set up Operation TRACE to re-examine the cases of missing women.
Based in Naas, Co. Kildare, detectives were tasked with collating and reviewing the cases of Ireland’s missing women.
Unable to link the victims to any perpetrator, in particular, prayers for a positive lead were answered in 2000 when the cold and calculated Larry Murphy was caught redhanded after he repeatedly raped, and attempted to kill a woman from Co. Carlow.
Murphy had abducted the woman from a car park and brought her to two locations in Wicklow where he carried out his brutal attack.
The woman was rescued when two hunters, who knew Murphy, came upon the scene and managed to scare Larry off.
After taking her to the Garda station, officers were dispatched the following morning to take him in for questioning.
When officers in the TRACE office got the call about the Baltinglass man, they began to assess the idea that he could be the man behind the disappearances of the women.
Operation Trace disbanded in 2003. Despite following every connection between Murphy and the missing women, no definitive conclusion was reached and there was not enough evidence to bring criminal charges against him.
That was until almost 10 years later when a former cellmate of the notorious rapist came forward to reveal that Larry Murphy confessed to him that he was the one who murdered Deirdre Jacob.
The former fellow prisoner of the ‘Beast of Baltinglass’ told Detective Alan Bailey that during Murphy’s stint behind bars for the incident in 2000 made the confession while drunk on prison hooch.
He relayed that Murphy admitted that he approached Deirdre outside her parent’s home to ask her for directions.
Murphy confessed he had scattered children's toys on the back seat of his car so that his victim would be more comfortable talking to him through the passenger window.
Once Deirdre leaned in he allegedly knocked her unconscious and dragged her into the front seat of the car.
The witness then told officers how Murphy wanted to take her to the mountains and rape her but that he couldn't control her when he took her out of the car and after putting up a good fight, he grabbed a hammer and hit her with it, killing her before dumping her body in a lake.
As a result, in December 2012, a specialist team with the assistance of the Garda Sub-Aqua team trawled parts of a Wicklow lake looking for the missing student's body. However, nothing was found.
Six years later, another break in the case came when Gardai announced that the case was being upgraded to a murder investigation.
Gardai saying that they had received vital new "credible and corroborated" information that led to Larry Murphy becoming the chief suspect in the murder of the 18-year-old.
By February 2020, gardai prepared all their evidence in the case and sent a file linking Murphy to the murder of Deirdre Jacob to the Director of Public Prosecutions.
Last year, the DPP sent their file on to a specialist barrister for a "second opinion" on the case.
In 2021, a dig took place at a wooded area in Brewel East after a witness told gardai he saw a car with an open boot reversing into the area, almost 18km from Newbridge, on the day Deirdre vanished.
Unfortunately, nothing relating to the case was found during the excavation.
As the Deirdre’s family, Gardai and the public waited with bated breath to find out what conclusion the DPP would come to, there was disappointment in July when it was determined that criminal charges would not be brought against Murphy.
On July 16th, it was revealed that the DPP returned to Gardai with a direction of ‘no prosecution’.
Following the disappointing news, Detective Alan Bailey told Sunday World that Gardai will need to find her body if they wish to press charges.
“The investigation team was always up against it without her body having been found,” he said.
“That would be one of the biggest problems for the investigation team.”
“Without that, it is very difficult to prove there was an actual murder or that someone has died,” he continued.
“That was always a problem and it will be a problem with bringing a prosecution in relation to the cases of any of the women whose disappearances formed the basis of Operation Trace.”
“They have to keep looking for her body. And that’s why they have never given up trying to find any of the missing women.”
It was also revealed that the one piece of evidence filed was CCTV footage of a person of interest, believed to be Larry Murphy.
The footage was put through rigorous forensic enhancement and showed a man, believed to be Murphy, outside the post office in Newbridge on the day Deirdre vanished.
The person was “in and around the post office” close to the time the teen called in to post a bank draft to London.
They tracked down a number of Murphy’s former work colleagues and other people who knew Murphy back in 1998, when he was a carpenter in Leinster.
Most were living overseas, requiring gardaí to travel abroad to interview them.
Each was asked to identify the individual in the enhanced CCTV footage, but gardaí received conflicting accounts.
However it is understood that at least one person identified the individual in the image as resembling Larry Murphy.
Following the news that the DPP would not be prosecuting Murphy, on July 24th, the Sunday Independent revealed a second person corroborated the story that Murphy admitted to murder behind bars.
The inmate came forward to Gardaí in 2006 to allege that Murphy, told him "I killed too” or "I killed two” during an altercation at Arbour Hill prison.
The prisoner also alleged that on another occasion Murphy sat in the prison yard discussing good hiding places around Glencullen in the Dublin Mountains with convicted murderers Frank McCann and David Lawler.
He also claimed that he told another prisoner that Gardaí would never be able to find DNA on his victims because he “didn’t leave any.”
24 years on, the whereabouts of Deirdre Jacob remains a mystery. With the case still open and active, Gardai have appealed to anyone with information to contact the investigation team in Kildare Garda Station on 045 521222 or the Garda Confidential Line 1800 666 111.