FOR Ciaran Bishop, it is the A£10 note he took from his wallet and handed fondly to his beloved daughter on Hallowe'en night. For Marian Edwards, it is the lift into Limerick city she organised for her son Jonathan. The families of murder victims are haunted for the rest of their lives by the what-ifs.
If Ciaran had not given his teenage daughter Gillian the money that stormy night in 1991, he knows his wife May would have given it to her.
But a few hours after she left with her Dad's A£10 in her bag, Michael Dean McLaughlin, a local man their daughter had never met before, beat her and then suffocated her by forcing a pound coin down her throat, leaving her body in an abandoned yard in her home town of Bray, Co Wicklow.
Marian Edwards asked a neighbour to give her son Jonathan a lift into a Limerick city housing estate in August 2001 to save him having to cycle over a dangerous bridge. The following morning, Jonathan died from a head injury inflicted in the aftermath of the stabbing of Eric Leamy on the estate.
In the middle of the nights that have followed their children's deaths, the parents of murder victims find it impossible to escape the thoughts of what might have been if they had done one small thing differently.
It is impossible to imagine the pain Mark and Majella Holohan are facing, haunted by memories of buying a BMX for their eldest child, watching Robert's face when he saw it on Christmas morning, seeing him polish it the day he disappeared.
Last week, they had to watch a boy who was not their son riding the silver BMX, dressed in similar clothes and pedalling fast for the reconstruction. The bike, with its distinctive wide axles, was the heart's desire of an 11year old boy with ramps to jump, friends' houses to visit and country roads to explore.
Losing a loved one to murder expands the circle of grief and fear, psychologist John Donohoe explained during research for a book on the families of murder victims.
In the case of the Holohan murder, the circle seems to have taken in the whole country.
It will include almost anyone who ever bought their child a bike for Christmas and the hundreds of people who searched for a sign of Robert during the eight days that he was missing.
The wretched end to all those efforts has appalled and frightened thousands of people, adults and children, and ensured that Robert's name is added to the short but terrible list of children apparently murdered by a stranger.
The events in Midleton have tapped into the darkest night terrors of anyone who has ever worried about a child being late home.
But while everyone will empathise with the Holohan family, only those who have lost a child to murder can understand how the weeks and months will unfold from here. From the moment the search team spotted the body, the state had to step in and do its work.
That meant the boy's body had to be left in the briars, untouched and undisturbed until daylight returned and the state pathologist Marie Cassidy had completed her examination. A forensic tent could be erected, but on one of the coldest nights of the year it was distressing even for those just watching events unfold on a television screen to imagine the boy lying there overnight.
The psychological impact of the murder of a child on the family is immense. It is already the kind of bereavement that is most difficult for people to deal with. The parental role as protector and nurturer is lost. The parent feels powerless and overwhelmed as events slip out of their control. Ciaran Bishop felt it physically the morning his daughter's body was found. His legs gave out from under him when he saw the gardai converging on the seafront house in Bray, the spot where Gillian's body had been dumped.
Their world, as Majella Holohan said in a radio appeal last week before Robert's body was found, is turned on its head.
The focus for their grief is also a huge psychological stumbling block. Instead of remembering how their child lived and the happiness they enjoyed, thoughts naturally turn to how the child died, the person or people who killed them and any subsequent trial.
Speaking to mothers who had lost children of any age, the common yearning was a longing to hold their child.
For Dolores Lawlor, whose 17-year-old son Patrick was killed in January 1999 and buried by the Grand Canal in Dublin, that longing never left her. Even though her son had been buried three years and 19 days before his body was found, she begged gardai to wrap his remains in a towel so that she could hold him again.
The third factor in bereavement through murder is the involvement of all sorts of professionals: the medics, the media, gardai, and legal professionals. All have a job to do, and in the case of the state personnel working on a murder, it is to investigate and then prosecute on behalf of the state. A garda liaison officer will work closely with a family to keep them informed of developments, but officially they are bystanders to the process that unfolds.
"The family doesn't really know what's happening to them now, " Ciaran Bishop said on Friday. They have been living in the intensity of a huge search with the adrenalin of hope keeping them functioning. The couple allowed television cameras and microphones into their home to make brave and profoundly moving appeals for Robert's safe return.
The media have been part of the search from the first day, with reporters sitting in Midleton station the first to hear the two-way radio news from the search team that a body had been found. Now the village has closed in protectively around the Holohans.
"In a few weeks time when they are just living and are not so preoccupied, when they are just sitting there on their own, that's when it happens, when the realisation sinks in, " Bishop said. His daughter was only missing overnight, but when he returned to the family home it was swamped with people.
He was not able to physically get across the room to his wife.
"There is only voluntary support out there for them.
There is no structure in place to support that family. If someone is convicted for this they will work on him for the next 10 to 15 years to make him better. There's nothing wrong with the idea of rehabilitation. But it's the family that needs support. There's nowhere that they can go to get that support 10 or 15 years down the line. Everybody's concerned now, but that will just ebb away. People might cross the other side of the road in three or four months time because they won't know what to say." In a way they will be almost afraid of the family, Ciaran believes, afraid of the idea that it could have been their child.
"With us, even the best of people stayed away the Christmas after Jill's death because nobody knew what to say."
Life Sentence: Murder Victims and their Families by Catherine Cleary is published by O'Brien Press.