It is a parent's worst nightmare. A child disappears, and gradually it becomes numbingly apparent that something terrible has happened.
Then the child's body is discovered, showing evidence of abduction, abuse and eventual murder.
The perpetrators of such deeds are, understandably, the objects of the hatred not only of the parents, but of society as a whole.
Who could inflict such suffering on an unknown child, for no reason other than the satisfaction of their own perverted desires?
Such people are seen as subhuman, and society flails around wildly in its attempts to punish and thwart them.
But many of the proposals that emerge from such collective grief and anger are far removed from a rational approach to the problem of child abuse, and will do little to protect children from abusers.
One of the most popular is the so-called "paedophile register", according to which the names and addresses of convicted paedophiles are placed on a register, which is accessible to the police and, usually, professionals involved with children. Last week the Irish Society for the Prevention of Cruelty to Children (ISPCC) advocated "controlled" access by the public as well to such a register.
The Minister for Justice, Mr O'Donoghue, responded by pointing to his Sex Offenders Bill, published earlier this year, which provides for the registration of all sex offenders sentenced to more than six months' imprisonment.
The names would, according to the proposed Bill, be released on a strict "need to know" basis.
This measure was included in the Bill despite the earlier views of officials in the Department of Justice that it was neither necessary nor useful.
One of the reasons it was made law in Britain was that there are a number of autonomous police forces there, with no common records, and without the register there was no way of tracking the movements of convicted paedophiles who posed a continuing risk following their release from prison. But we have only one police force in the Republic, which is notified of the release of serious offenders, so this argument does not apply.
However, given the introduction of such a register in the UK, and the ease of travel to this State, it was probably inevitable that similar measures would follow here. And so they did.
But we should not think that the introduction of such a register will protect most children from abuse; it could even be counterproductive if it gave the illusion that it did.
Despite the horror evoked by the abduction and subsequent murder of children, the fact remains that this is a very rare occurrence.
In terms of threats to children's lives, it falls far below that posed by irresponsible drivers.
In terms of the threat of sexual abuse, that posed by marauding fixated paedophiles is infinitesimal compared to that posed by people known to children, both within the family and within the child's wider caring and educational community, who "groom" children they know for abuse.
Further, the proposed register is of convicted paedophiles.
It is estimated that for every person charged with such an offence, 19 are never apprehended.
Only a percentage of those charged are convicted.
What is even more worrying is that the terms "paedophile" and "sex offender" appear to have become interchangeable.
The Sex Offenders Bill proposes to register all convicted sex offenders.
This includes those who rape adult women and men, those who abuse within their own family, and teenagers who, by engaging in consensual sex under the age of 16, are committing a crime.
The majority of these people pose no threat to children.
There is also an enormous difference between those who abuse children within their families and the type of fixated paedophile who stalks and abducts children in order to abuse and, in certain cases, murder them.
Such people can be suffering from serious personality disorders.
They are also frequently very clever and well organised, precisely the sort of people who can evade measures like a register.
A week ago an English newspaper published an interview with a convicted paedophile, who had been offered false documents by the friends he had made in prison.
As someone who had been treated and who said he felt no inclination to reoffend, he refused, but the "name and shame" threat made by the News of the World campaign provided a motive to accept.
Those fixated paedophiles who target children for abuse, to the point of occasionally posing a threat to their lives, do present a challenge to the legal justice system.
If they are apprehended, charged and convicted, as a minority are, they often prove resistant to treatment.
On release, they may still pose a risk to children.
A register does not solve this problem.
It requires a more complex answer, involving creative sentencing policies that include treatment, ongoing assessment, a system of release on licence and continual monitoring following release.
It also involves reasoned debate on the civil liberties implications of what would effectively be an open-ended sentence, which may indeed be justified by concerns for child protection.
Such an approach would require resources and the provision of highly skilled personnel to deal with such offenders.
It would be more costly, and more complicated, to explain than a headline-grabbing quick-fix solution, which makes no distinction between those who pose a threat to children and those who do not.
But should this be a consideration?
