Paul Williams: '20 years on, Raonaid Murray's death is the longest-running murder probe in modern Irish history'
The horrific murder of an innocent 17-year-old child called Raonaid Murray has haunted Irish society for two decades - and will do so until it is solved.
Gardaí and the schoolgirl's family made yet another public appeal for that vital piece of information that could unlock the motive behind one of the country's most shocking homicide mysteries - and bring the teenager's killer to justice.
Each anniversary of this monstrous crime has been marked by a plea from Raonaid's family for anyone with information to come forward.
Together with gardaí in Dún Laoghaire, where the investigation is based, they have ensured this case has not been allowed to fade from public memory.
More importantly, it has not been allowed to fade from the memory of the assailant - and whoever is covering for them.
Most of the population are intuitively aware of this murder and instantly recognise the picture of Raonaid which accompanies every appeal and media story, that of a pretty teen with blonde locks framing her face.
That picture has helped remind the public of the enormity of this crime - this was an innocent child with a life full of promise and potential stretching out ahead of her.
Read more here: 'Do the right thing,' father of Raonaid tells killer
Raonaid had not lived long enough to incite the type of mindless hatred which characterised the violence used to snuff out her future.
This remains the biggest and longest-running active murder investigation in modern Irish history with more than 200 potential suspects identified as persons of interest, 22 of whom were given 'red alert' status at various stages.
There were 14 individuals arrested, of whom 11 were questioned about the murder and the rest for allegedly withholding information.
Detectives interviewed 3,500 individuals as they tracked down people who had been socialising in the Dún Laoghaire and Glenageary area that night.
Investigators even interviewed the entire crew of an Irish Navy ship which had been docked in Dún Laoghaire that weekend.
But despite the herculean effort, yesterday's joint statement from gardaí and the family admit "there is in reality no prime suspect" because gardaí have been unable to identify a motive.
Raonaid was left fatally injured after suffering a flurry of frenzied stab wounds within a timeframe of an hour around midnight on the evening of Friday, September 3, 1999.
At 9.40pm she had left the Sally West boutique in Dún Laoghaire shopping centre, where she worked part-time, and crossed George's Street to meet friends in Scott's pub.
Between 11.20pm and 11.40pm Raonaid left Scott's to go home to change into a new outfit she got earlier that evening and then join friends in Paparazzi's disco.
The family home was at Silchester Park, a 15-minute walk from the centre of town. Gardaí could not establish the route she took, but one eye-witness placed her in an argument with a young man on Glenageary Road Upper. She then crossed to Silchester Road, turning into a laneway called 'the Cut' which led towards her home. It was here, on this darkened laneway, her killer struck.
Forensic examination would later show the attacker stabbed Raonaid more than 30 times, most likely using a kitchen knife. While most of the knife strikes barely penetrated her clothes, Raonaid's attacker did inflict four deep wounds to her side, chest and shoulder which proved fatal.
The forensic investigation established the fatally injured teenager managed to crawl along the laneway for about 500 metres before collapsing.
Adding to the tragedy is the fact it was Raonaid's sister, Sarah, and some friends who discovered her body after noticing something lying on the path around 12.30am.
She was still clutching the bag containing her new outfit in her hand.
The investigation has not been without controversy - not to mention the many theories regarding the motive and identity of the killer.
A review of the case file by the Garda Serious Crime Review team identified a number of deficiencies in the initial investigation, including the fact internal rivalries and mixed loyalties meant investigators were not communicating as they should have.
At one stage, the then head of the cold case unit, Chief Superintendent Christy Mangan, sent detectives to the USA to consult with experienced profilers who suggested the killer may have been a female who was known to Raonaid.
Another suspect was Farah Noor, the Somalian national murdered and dismembered by the so-called Scissor Sisters, Linda and Charlotte Mulhall, in 2005. Noor had been one of the potential suspects questioned at the time.
His killers even told gardaí that he had once bragged he had been responsible for the murder - but investigators have long since ruled this out.
When he was unmasked as the killer of Elaine O'Hara, Graham Dwyer was also the subject of wild speculation in relation to the death of Raonaid, but he too was ruled out.
Gardaí still believe Raonaid's killer was known to her, and may have been part of her wider peer group.
That is why investigators have repeatedly appealed to possible witnesses who "were then Raonaid's age, are now parents themselves with children, some of whom would now be close to Raonaid's age, and we would ask them to reflect now, with the benefit of maturity and hindsight, for any information which may be of assistance".
Despite the passage of time, there is good reason to believe this murder will eventually be solved. Inevitably the killer will have confided in someone at some stage over the past two decades and experience has shown those carrying such secrets eventually spill the beans.
As the old detective's saying goes: in the end, the bones of the dead will always call out for justice.