There is a video online of Amy Fitzpatrick taken by one of her friends in the months before she went missing.
She is engaging in a typical teenage girl pastime, dancing in the bedroom, with a pretend microphone as the music blares out.
Except in her case, the camera-phone fails to capture her outright, she keeps trying to hide behind the door as her friends laugh.
Those who know her well, say that Amy is naturally shy, only revealing a slightly goofy sense of humour with those she feels safe with.
More than five years on from when that short video-clip of Amy was taken, her whereabouts remain unknown.
Her friends still post occasional messages to her online, they have gone on to celebrate her 18th and 21st birthdays, but she remains frozen in time, the slightly built Dublin girl with the big blue eyes.
As her family and his partner mourn the loss of her brother Dean, that tragedy understandably overshadows Amy's mysterious disappearance. But it should not mean that Amy herself is forgotten. The idea that a vulnerable teenager, an Irish citizen, remains missing in another country, is something that we should continue to talk about, and be concerned about.
When a young person goes missing, police often face a different set of difficulties than in the case of an adult. A teenager may not have disclosed their fears or worries, friends or family may not be aware of particular incidents which may have given them cause for concern.
But as they grow older, those small details which may not have been recalled or even seemed relevant at the time, suddenly come to the surface.
They may be afraid themselves, fearing censure, or perhaps an adult told them not to get involved. But long-running investigations often depend on witness remorse or recall.
When similar crimes occur in the same area, or involving people who may have come to their attention at the time, case-files may be dusted off, and links made.
Having dealt with unsolved cases both on radio and television, and interviewed both the relatives of those murdered and missing, one thing always struck me. For a case to remain current then it usually comes down to one or two people. There will be a parent or sibling who continues to highlight their loved one's disappearance or death, and a detective who won't give up, long after the media spotlight has moved on elsewhere.
They are the ones who keep faith, but they depend on us the public to keep faith also. Sometimes it's the little details in a crime that mean you continue to remain interested when some new piece of evidence or appeal for information arrives. In the case of Amy, it was the fact that she was in a foreign country that made people sit up and take notice. For parents, it was the knowledge that though they may act like they don't need us, our teenagers equally depend on us for their safety. The fact that she went missing after Christmas, a time when most families are enjoying peace and togetherness, also struck a chord.
People were equally concerned that though last seen on January 1, she was reported missing on January 3, 36 hours after she failed to return home. The first 24 hours in any missing person investigation are vital. Initially, the Guardia Civil were treating the case as a missing person, with initial reports suggesting that Amy might have run away. Though volunteers and police did some searching, the first large-scale search of the area around Calahonda, Costa del Sol, began on January 9 and was scaled down a week later.
As with Madeleine McCann, dealing with a different police structure and language, adds another layer of bureaucracy which may undermine the urgency of an investigation.
Sometimes local police are deliberately fed false trails, on other occasions memory proves fallible.
Or guilt means that people do not tell them the full story lest they too are implicated.
As well as the pain of not knowing where a loved one is, for families of the missing, there's also the public judgement to contend with. Why did the person go missing, we ask, was there something at home that upset them. Or had the missing person other problems?
In Amy's case much of the curiosity centred both on the fact that she was spending periods staying with friends' families, and that the photos being used in her posters made her look older and more sophisticated than her real age.
In reality, all of that is meaningless, the one thing that is definitely known is that she is highly unlikely to have disappeared of her own accord. She left her friend Ashley Rose's house late on New Year's Day, 2008, clutching a plastic bag with some clothes in it, and little else. Both her mobile phone, the lifeline of every teenager, and her passport were still in her mother's house. She had no money, and there have been no confirmed sightings since then. Despite poster campaigns, searches and various appeals, Amy is still missing and no one has ever been charged with her disappearance.
A cursory glance at English language Spanish news sites show that, for all of its family holiday image, Southern Spain has also become a shady place for shady people. If carrying an Irish passport means anything, it means that we should be doing everything within our power to ensure that Amy's disappearance remains a live investigation.
Getting the police there to liaise with the police here, allowing for the translation of files, and the exchange of information would be a start. Some of those teenagers who were friends with Amy now live in the UK, this might be the time to re-interview them. With the benefit of hindsight they might have fresh information that might assist the investigation.
The one great knowable about the criminal mindset is that people who do bad things to other people like to bask in their notoriety.
They talk, and sometimes they talk too much and trip themselves up. TV programmes such as Crimecall depend not just on the law-abiding public for information. Sometimes the caller may be a disgruntled ex-partner or relative.
It may also be somebody who is eaten up with the guilt of what they know. They see an ageing parent make an appeal for information and they realise that not only do they hold the key, they need to hand over that last bit of the puzzle.
Among the many missing person's cases that I have covered on programmes over the years, certain cases remain in my mind's eye, and that is all down to the families who still campaign for their missing loved ones.
Crimecall, while I was working on it, reconstructed the last known movements of missing schoolboy Philip Cairns. Philip's brother Eoin agreed to be interviewed in his older sibling's secondary school, and spoke very movingly about him.
The Cairns family has endured great pain over the years, but has handled the burden with tremendous dignity.
Similarly, the father and sister of Trevor Deely were guests on a special half-hour radio programme in which they talked lovingly about Trevor, and how they were coping.
One thing that Trevor's father Michael said struck me forcibly. A counsellor had told them that the logical reaction to Trevor's disappearance is that he is still alive as there is no evidence to the contrary.
Sometimes well-meaning people suggest to families that they give up, and get on with their own lives, accept that their loved one is dead and get on with it. Yet to do that, a family is in a way, denying everything that their mind and senses are telling them.
One mother of a missing teenager, whose body was eventually found two years after he disappeared, told me of how she dealt with people who told her that she should concentrate on her other children. "I ask them would they give up if it was their child, and I've yet to meet anyone who said that they would."
Missing persons is the poor relation of serious crime investigation. Without a body, or fresh information, police have little to go on. Eventually the impetus evaporates, other crimes occur and resources are withdrawn.
On the Irish missing children's website, many of those featured are teenagers. The one thing some of them have in common is that they are from other countries, from China, from Africa for example. Far away from home, the fact that they are missing has gotten little publicity. Which is what those who may have caused them harm depend upon, that if no one cares, then no one asks questions.
Amy too was far away from home, and by all accounts desperately missing Ireland. Don't let's give up on her.