Has there ever been a more difficult instruction from a judge? "Let the shock drift away." Those were the words of Mr Justice Tony Hunt to the jury as they retired to consider a verdict in the trial of architect Graham Dwyer for the 2012 murder of Elaine O'Hara.
Even for those who had observed the trial at a distance for the last number of weeks, that was hard enough. Certain images have been burned onto the collective consciousness that will be hard to eradicate.
For those who worked on the case, and for the five women and seven men of the jury at the Central Criminal Court who had to watch videos of Dwyer stabbing O'Hara and other women during intercourse, it must be impossible. The eye cannot unsee what it has seen. The mind does not forget on command.
Now that Dwyer has been found guilty of murdering 36- year-old Elaine O'Hara for his sexual gratification, hours after she was discharged from a mental hospital, attention naturally turns to deciphering once more what makes a monster tick, and what forces drove him to do what he did.
But how does one even begin to make sense of it? If nothing else, this story is a reminder that the inner worlds of seemingly unremarkable people may be far darker than those who know and love them can possibly imagine, or even care to acknowledge, because sometimes it's best not to know.
If seemingly normal people living ordinary, dull, suburban lives - shopping, playing golf, gardening, having dinner parties - may at the same time be harbouring the most deranged, violent fantasies about striking women with hammers or murdering perfect strangers met whilst out walking in the mountains, how can the world ever feel safe or familiar again?
Somehow it's the details which seem most disturbing. Those small, weird contradictions. Smoking "disgusted" Dwyer, but he wanted to stab women. As ever, when someone commits an appalling crime, whether it's taking the life of a vulnerable young woman, or crashing a plane into the side of a mountain, the hunt begins for clues, hints, precursors, as if there was some parallel reality in which we could have somehow foreseen the crime and prevented the horror. The purpose is to make ourselves feel better, and to shield our minds from the more terrifying truth, which is that there's no way of knowing what goes on in other people's heads.
How can you ever know what they're really thinking? What they really want? Each face is a mask. What goes on behind it, a mystery.
That's true on the most basic level. When it comes to sexual fantasies, the mystery only deepens. The public space has never been more highly sexualised; erotic imagery surrounds us every minute of the day, and we fool ourselves that it's all harmless and healthy. Most of the time it is. But unfettered sexual desire can take those in its grip to places far removed from a desensitised culture's romantic cliches. Desire is a Pandora's box. Open it at your peril. Who knows what might come flying out? Something led Dwyer to lift that lid, and whatever was inside consumed him.
Seeking to encapsulate what was said about him during the summing up, the headlines spoke of Dwyer as "a middle-class professional with dark secrets", but how many others could that describe? And how disturbing might it be to find out? How many more Graham Dwyers are there? They might not ever bring their fantasies to murderous fruition, but that doesn't mean they're not playing with psychological fire.
That's what makes this story so unnerving. Prosecution lawyer, Sean Guerin SC, described Dwyer as a "sadistic, brutal pervert with nothing on his mind other than murder" - but of course that's not strictly true.
He had plenty of other things on his mind. His wife. His family. His career. His love of model planes. It just so happened that these commonplace thoughts were capable of co-existing alongside a will so damaged and evil that it felt itself entitled to decide who lives and dies. In that respect, Dwyer's mental state was different from that of countless others only by degrees, not in its nature.
Dwyer's behaviour lay at the disordered end of a spectrum, but in how he saw women, it was a recognisable spectrum. It's possible to detect echoes of conventionally accepted relationship rituals in the messages from the "Master" and "Slave" phones.
The way in which Graham Dwyer undermined Elaine O'Hara's sense of self in order to maximise her dependency upon him is not so dissimilar from the advice given to men by pick-up artists, widely circulated in books and online, about how to snare potential sexual partners. The "Neg", an insult wrapped up in a compliment which is used to unpick women's confidence and make them more receptive to seduction, is a particular favourite, so is isolation. Separate a woman from the world around her, and her gratitude at any attention, however twisted, will be heightened. The malevolent seducer has his box of tricks, and Graham Dwyer used exactly the same techniques on Elaine O'Hara.
In most hands, these methods of opportunistic ensnarement are nothing more than pathetic manoeuvres by needy little boys too scared to approach women as equals.
In the hands of sociopaths, they become much more dangerous tools. Further combine that heady psychological power trip with the world of BDSM, a loose set of initials describing a range of sexual acts involving bondage, domination, restraint and submission, and the darkness can easily become overwhelming.
In 2007, I co-wrote a crime novel called The Judas Heart which imagined a young woman with self-destructive violent fantasies who becomes involved in the S&M scene in Dublin and ends up being murdered. At the time, researching the subject, it all seemed so implausible that we feared no one would believe a word of it. Even the idea that there were S&M clubs to speak of sounded ridiculous. In Dublin? Seriously?
Ten years on, the imagery and language of BDSM have become so ubiquitous, thanks to Fifty Shades Of Grey and other such fatuous nonsense, that it has almost come to be seen as nothing more than harmless fun. A deeper truth was revealed in this trial.
Fantasy has no rules. Nor should it. What goes on inside the skull cannot be policed. What happens between consenting adults, likewise. If two people get their kicks either from fantasising about violence, or even committing it upon one another within certain restrictions, then that's their business. Most of those who get involved in this scene would never dream of hurting another human being for real, much less crossing a line into murder; but it's foolish to deny that those who dip a toe into this world are flirting with psychological forces that they simply don't understand, and can certainly not control, and that allowing such emotions to be normalised in one's sexual identity can deaden the conscience and lead inexorably to deeper transgressions.
For some to be Masters, there must be Slaves. That's where vulnerable people can be manipulated into doing things they don't really want to do by more powerful and dominant personalities. Elaine O'Hara went through a door willingly, but, once she was on the other side, she was no longer in control of her life. Her messages make it clear that this is not what she wanted. "Please don't mention killing for a while, just until I settle back into life. . . I want to try to have a normal life without talking and thinking about that. . . Please don't kill me, please. Sir, I don't want to die. I'm scared you're going to kill me." What she wants is to find a partner to love and care for her and give her a child.
"I don't want to die." It couldn't have been plainer. Dwyer's ego was so distorted by fantasy that he refused, or was unable, to hear; but the danger is always that concentrating on the perversely glamorous allure of evil snuffs out all other sources of light. To fixate on him merely plays his game. In symbolic terms, he's still the Master, and we're all his Slaves, our imaginations stained by his shadow.
It's not Dwyer who should be remembered, but the women in his life. Or rather his lives. His real life. His secret life. His fantasy life. His wife, not least, another innocent victim plunged into an alien landscape from which it must seem at times as if there is no escape. Then there's the real women about whose murders he fantasised; the world must always feel slightly out of kilter after knowing what this man had in store for them. What he would have done to them if he had his way.
Most of all, there's Elaine O'Hara. It's often lamented in murder trials that the victim gets forgotten, but that hasn't been the case with Elaine.
This woman, her life, her struggles and troubles, were placed absolutely at the centre of the trial. She was not some anonymous victim, but a real woman that those looking in from the outside felt they came to know, and care about.
This is what made so much of the evidence painful to hear and hard to forget.
All too often, replaying a victim's life in reverse from the point of death, it can seem as if it was one long descent to an inevitable end. What's heartbreaking about Elaine, as her life was sensitively reconstructed by police and prosecutors alike, was realising that she could have been saved. From Dwyer. From herself. He treated her like an object. The trial restored her humanity.
It's those women who should stay in our minds, not the man who felt his sexual appetites gave him the right to tear apart their lives.
Graham Dwyer Trial
He might have been in the audience of The Late Late Show once and appeared briefly in the RTE Beyond the Hall Door programme talking about a bathroom he had designed with "easy to clean" lino on the floor.
Graham Dwyer Trial
In an article entitled 'Life on a Knife Edge' in the January online edition of Psychology Today, Dr Mark Griffiths of Nottingham Trent University recounts episodes of "piquerism", the mainly male perversion which is defined as "paraphilic sexual arousal which hinges on the sadistic piercing and stabbing of another person, especially in the breast, buttocks and groin, which may cause enough bleeding to be fatal".