Michael Deely says he will never give up hope of solving the mystery behind his missing son Trevor's disappearance 15 years ago.
The determined Deely family spearheaded an intensive missing person search after Trevor vanished one rainy night in Dublin during December, 2000.
Today marks the 15th anniversary of his disappearance and the search continues.
"We might annoy people into a 'not again' response but we will keep telling Trevor's story so that people will keep a lookout," said Michael Deely, now aged 73. "We would apologise if it bores some people but, from our family's point of view, it is very necessary."
A senior garda said the Deely family "set the standard" for all other families of missing persons when organising search efforts.
Within days of his disappearance, the Deelys had covered lamposts in the city with his photograph and begun a campaign to keep his name and image alive.
Trevor, a thin man of 22, was over six feet tall with reddish-blond hair. He disappeared without trace on the night of his office Christmas party.
The last sighting of him was a CCTV image recorded by a camera on Baggot Street Bridge at 4.14am on December 8. It was raining heavily and he carried a big blue umbrella with an ACC bank logo as he walked towards Haddington Road.
After that, nothing.
'What became of Trevor Deely?' is a question that continues to intrigue people because, over the years, his family and friends have taken action to keep Trevor in the public mind.
Trevor's father said that he needs to remain strong and hopeful that they will some day discover the truth.
"I get tired but my nature is optimistic," said his father. "I have a responsibility to the rest of my family. If they see me cave in, how can I expect them to keep going? It's important that I stay strong."
Trevor was no longer living at home with his family in Naas but was sharing an apartment in Serpentine Avenue in Ballsbridge. On that fateful night, his path home would have taken him across the Grand Canal and then over the Dodder at Ballsbridge to get to the apartment.
Michael emphasised that Trevor, although he had been drinking alcohol, was not drunk or in any way disorientated.
"There was no way he was out of his head," he said.
Trevor left Buck Whaley's nightclub in Leeson Street and entered his workplace nearby at Bank of Ireland Asset Management at 3.25am.
Trevor was a member of the IT department of the bank and when he arrived he was "drowned wet", said fellow staff member Karl Pender who was working overnight in IT.
Trevor chatted with Karl, briefly logged onto his computer, then went for a coffee with Karl to the office canteen and chatted about the night's Christmas party. He picked up a big umbrella and left the building as the rain poured down.
Around 4am, Trevor called his close friend Glen Cullen and left a voice message telling him he was on his way home and he would talk to him tomorrow. He never reached his apartment.
Michael is convinced his son did not take his own life. "There was never a semblance of that. He came from a happy family," said Michael, who spoke at length about how Trevor was always at ease with people.
"Trevor was very personable. He found mixing very easy with all age groups. He was very mature and dependable," he said.
Trevor loved his IT job, which he took to "like a duck to water", and he was becoming increasingly interested in watching inter-county football, particularly the games of his native Kildare and Michael's native county Galway, he said.
Searches of the Grand Canal and the River Dodder yielded nothing.
Trevor's sister Michelle was living in London at the time and she made a number of calls to Trevor's phone over the next couple of days before anyone realised he was missing. She said she could hear Trevor's phone ringing several times. A technology expert indicated the phone would not be heard ringing by a caller if it had been submerged in water while switched on.
Could Trevor have been murdered by muggers who made his body disappear by hiding it in a skip or big bin or by some other method? The visit of Bill Clinton that weekend meant all big bins were collected and emptied for security purposes.
Or was he abducted? Could he have left Ireland without trace?
These questions continue to haunt the Deely family.
One of Michael's favourite memories of his youngest son is the image of him striding ahead of every other athlete in a cross country run at Punchestown racecourse. Trevor won the race and a photograph of his victory appeared in the local Leinster Leader.
"I remember him with his hair long and it was blowing in the breeze and the rest of the runners coming behind him. You'd swear it was first place in the Olympics," said the smiling father.
Michael said he would like the gardai to open up a cold case investigation. When he sees such investigations succeed, his hope rises.
"The Garda Commissioner said recently she intended giving more resources to missing persons investigations. I'd like to see everything in Trevor's case re-opened and for new people to take a fresh look at Trevor's case," he said.
Michael and his wife Ann became grandparents for the first time after Trevor's disappearance. Their son Mark now has four girls, daughter Pamela has three boys, and daughter Michelle has two girls.
Michael takes comfort in prayer. Their parish priest Fr John Brickley has been a constant support to the family. A prayer service of hope for Trevor was held in the family's local Ballycane Church last Friday.
"I also get comfort when strangers stop me in the street in Naas and ask me if I'm Trevor's father. The fact that they mention his name matters a great deal to me," he said. "It's at such times that I hope it will turn out right yet."
Any information should be made available to gardai at Pearse Street on 01-6669000.