Everyone remembers, of course, the young mother who met a violent death in her own home in the Dublin commuter belt in 2004, and whose husband was subsequently charged with her murder. Who could forget the awful fate of Colleen Mulder, strangled to death in Dunshaughlin? Or that of Mamie Walsh, the Waterford mother of two, whose body was found in the boot of her car in August that year, covered in a bloodstained sheet and with a rope tied loosely around her neck?
At the trial of Samuel Jennings, who was found guilty of her murder, the members of her family who had been present when the car boot was opened said, in words of searing clarity: "How poor Mamie looked on the outside then is how we all feel on the inside now." Or Dolores McCrea, a mother of four, whose burnt body was found at the back of her house in Co Donegal that same year? The murder trial of her husband heard that he had told his children he would rip his wife's guts out and stab her.
Or, if you're like me, you've forgotten all of these cases already. The initial reports on the violent deaths of these women were shocking. The trials were upsetting. But these events passed through the media mill in a more or less routine fashion. They gave us our little fix of horror and heartbreak, our regular reminder of the barbarism that can lie just under the surface of normality, and then we moved on.
In May, when the Court of Criminal Appeal ordered a retrial of the man who had been found guilty of Colleen Mulder's murder, the news hardly made it into the "other court stories in brief" columns.
None of these women were less human than Rachel O'Reilly. None of their families, friends and neighbours were less devastated, horrified or appalled by their deaths than Rachel's were. If motherhood is the special ingredient that turns a violent death into an epic media event, Colleen Mulder, Mamie Walsh and Dolores McCrea had it too.
If sheer awfulness is what makes us pay attention, these deaths had it in spades. So why did the murder of Rachel O'Reilly and the trial and conviction of her husband, Joe, become one of the biggest media events of recent years, while the other death and trials were treated as routine events? The only answer I can think of is a painful one for anyone who takes pride in the profession of journalism. The story became so big because the coverage was shaped by the killer.
If that seems like an over-dramatic claim, consider the account of the journalist who set the agenda, Mick McCaffrey, then a crime reporter with the Evening Herald.
In the Sunday Tribune, where he now works, McCaffrey described how, just weeks after Rachel's murder, Joe O'Reilly "suggested showing the newspaper around the bungalow which he said was still covered in Rachel's bloodstains". McCaffrey already suspected that O'Reilly may have killed his wife. He subsequently understood O'Reilly's behaviour as that of a psychopath getting a thrill from having everybody see him at the scene of his triumph. He "thought this was psychotic behaviour but as a journalist it was a fantastic story".
His editors clearly thought so too. The Herald'sfront page ran the strapline "Exclusive: Inside murdered Rachel's dream home" and the banner headline "Blood marks spot where mum's vicious killer struck". Beneath a photograph of bloodstains on a wall, there is one of Joe O'Reilly sitting proudly in the middle of the room where he killed his wife.
It is like one of those now-repulsive pictures of a big-game hunter in a pith helmet with his rifle in his hands and his foot resting on the dead body of a tiger. In return for a "fantastic story", journalism was feeding the monstrous ego of a psychopath.
It was also providing Joe O'Reilly with what may be the best grounds he has for an appeal. In a case that depended entirely on circumstantial evidence, and therefore on the willingness of the jury to read a pattern of guilt into disjointed fragments of suggestion and implication, it can be argued that the swathes of tendentious coverage fatally polluted the process of objective judgment.
Even if this proves not to be the case, it is impossible to argue that the media coverage as a whole has been in the public interest. Allowing a suspected killer to display his victim's bloodstains is a "fantastic story" only because it panders to our craving for grotesque sensation. But this story went far beyond sensationalism. The Herald, and to some extent the Late, Late Show, allowed a killer to influence the reporting of his crime. Joe O'Reilly upped the ante and all the media, to one degree or another, played along.
He decided that he did not wish to be treated as a routine little thug, and we obliged by turning his squalid, banal evil into a national epic.
Even if he has lost the game, he will take a sickening satisfaction from his ability to decide how it was played.