One evening a couple of weeks ago, I passed a murderer in the front square of Trinity College Dublin. He didn’t look like a murderer – or he didn’t look like whatever it is murderers are supposed to look like. With his wavy white hair swept back from his high forehead, his tweed jacket, his beige slacks and blue oxford shirt, he could easily have passed for a professor nearing retirement age, scuttling between lectures while trying to avoid running into his students. He was even carrying an A4-sized folder under one arm. At first I thought he was someone I vaguely knew, and was about to nod blandly in his direction, when I realized why it was that I had recognized him. I must have done a quite blatant double take, because as we passed each other beneath the campanile he shot me a sidelong look of almost cartoonish wariness and culpability – swiveling his eyes toward me, and then away, and then quickly back again. He looked frightened.

I stopped for a moment, and watched him walk across the cobbled square in the direction of Nassau Street. My first thought was this: That was Freddie Montgomery who just walked past me. And then I corrected myself: No, it wasn’t; it was Malcolm MacArthur. Freddie Montgomery is a fictional character, the murderer who narrates three novels by John Banville called The Book of Evidence, Ghosts, and Athena. Malcolm McArthur is not a fictional character – at least not in any straightforward sense; he is a man in his late sixties who spent the last thirty years in prison for killing two strangers in July of 1982. He was released in mid September. He is arguably the most notorious murderer in Ireland’s notoriously murderous history.

The MacArthur story is one that everyone in this country knows, and although the murders happened decades ago, his name is rarely out of the papers here for very long. Whenever he would come up for parole (which he was repeatedly denied), and whenever he was let out on day-release (which happened more frequently over the last few years), the story would be back in the news, his face returned to the front page. The photograph invariably used by the papers was a black and white mug shot depicting a man in his late thirties, foppish and bow-tied, with an expression of mournful, distant perplexity. He looked no more like a killer then than he does now. But then what does a killer look like?

At the time of the murders, MacArthur was a well-known socialite around Dublin. He was the son of a wealthy landowning family from Co. Meath, where many of the descendants of the country’s former Anglo-Irish ruling class still live, struggling to keep their imposing Georgian houses from falling into ruin. Although he had a young son with his partner, Brenda Little, his was apparently a familiar face in the underground gay bars and clubs of the city at a time when homosexual sex was still a criminal offense in the Republic. MacArthur, who lived off an inheritance fund, had been spending time in the Canary islands with his partner and their child when his money abruptly ran out. Inspired, he claims, by the IRA’s fundraising methodology, he decided that the only plausible means of maintaining his lifestyle was to pull off a series of armed robberies in Ireland before quietly leaving the country again and returning to Spain.

In Dublin a few days after his return, he found a personal ad in a newspaper placed by a farmer in Offaly with a gun for sale. MacArthur wanted the gun, but he needed a car to get to Offaly, in the rural midlands, and to get away from the scenes of the robberies he was planning to commit. So he bought a hammer. “I wanted this hammer,” as he put it in a statement he gave after his arrest, “to injure somebody, to get a car, to travel down the country to get a gun because I had no transport. In turn I had planned ahead to stick somebody up and the object was to get money. I had been reading in the newspapers about all the robberies and this seemed a way out of my obsessive financial situation.” MacArthur put the hammer in a satchel along with a shovel and a fake gun, and he set out for Phoenix Park on Dublin’s northside, stopping in a sweet shop on the quays to buy an orange, which he ate along the way. When he got there, he walked around for a bit until he came across a car parked close to the American ambassador’s residence.

Beside the car, its owner, a 27-year old nurse named Bridie Gargan, was sunbathing. The door of her car was open, and so MacArthur ordered Gargan to lie down in the back seat, and she panicked, and MacArthur became afraid that she would draw attention to them, and so he turned and hit her in the head with the hammer, and then hit her a second time because, as he put it, “the first blow did not do what I expected it to do.” As he was driving through the park, MacArthur was overtaken by an ambulance on the way to the nearby St. James’s hospital, where Gargan worked. The paramedics noticed her in the back seat, holding her bleeding head in her bloodied hands; seeing the hospital sticker on the windshield, they assumed that MacArthur was a doctor taking an injured patient to casualty, and escorted him to the gates of St. James’s. Instead of turning into the hospital’s grounds, however, he continued driving. He then abandoned the car in a lane way, leaving Bridie Gargan to finish dying in the back seat, and ducked into a pub, where he called a taxi to take him back to Dun Laoghaire, where he was staying.

Two days later, MacArthur took a bus to Offaly, and arranged a meeting for the following day with the farmer who was selling the rifle. The farmer, whose name was Donal Dunne, picked MacArthur up from the town of Edenderry and drove him to a nearby boggy area in order to test out the gun. He mentioned that it had cost him eleven hundred pounds, and that he was not interested in selling it at a loss. After MacArthur had fired the gun at an improvised target, Dunne put his hand on the barrel to take it back from him. “I’m sorry, old chap,” said MacArthur, and shot him in the face. He then hid the body in some bushes, took Dunne’s car and drove it back to Dublin.

As pointlessly horrible as these deeds of MacArthur’s were, it was what he did next that ensured they would never be forgotten. He made his way to the affluent little seaside town of Dalkey in south county Dublin (described by Flann O’Brien in The Dalkey Archive as “an unlikely town, huddled, quiet, pretending to be asleep”). There, he looked up a friend of his named Patrick Connolly who lived in an apartment overlooking the sea, and who took him in. He stayed at Connolly’s apartment until the police eventually tracked him down and arrested him there, having been tipped off by a neighbor about a man who resembled the suspect being seen around the building. When the circumstances of the arrest were made public, it ignited one of the most extraordinary political scandals in the country’s history. The reason for this was that Connolly wasn’t just some guy who unknowingly allowed a murderer to hide out in his home: he also happened to be Ireland’s Attorney General.

At the time of the arrest, Connolly had been preparing to leave the country for a holiday in America. He went ahead with the holiday, but was quickly called back by his boss, the Taoiseach (prime minister) Charles Haughey. In the succeeding days, the weirder details of the case began to leak out to the press. While MacArthur had been staying with Connolly, for instance, they had both attended the All-Ireland hurling semi-final at Croke Park Stadium. They sat in a VIP box, where they met the Garda Commissioner, the state’s most senior police officer. The attorney general and the commissioner discussed the murders while MacArthur sat and listened politely. On his return from the US, Haughey fired Connolly; rumors of a sexual relationship between himself and MacArthur proved spurious, but were a source of extreme embarrassment to the government at the time. Attempting to distance himself from the scandal, Haughey famously referred to the whole affair as “a bizarre happening, an unprecedented situation, a grotesque situation, an almost unbelievable mischance.” The journalist Conor Cruise-O’Brien coined the acronym “GUBU” (Grotesque, Unbelievable, Bizarre, Unprecedented), and the term quickly became synonymous with the events. The pressure of the public scandal seemed likely to collapse the already precarious government, but it limped on for a further few months until unconnected revelations about phone tapping finally brought it down.

I was a toddler when all this took place, and so I have no actual memories of any of it. But my grandparents happened to live in the apartment beside Connolly’s, and so I grew up knowing about the murderer who had been arrested next door, and I remember being transfixed by the idea that something like this could have happened in a place I knew so well, that was such a part of my guarded little world. Pulling up outside the building in the car with my parents, I would picture this man, this murderer, being hauled out the front door by police with sub-machine guns, helicopters circling the building, snipers on the roof of the retirement home across the street. I was independently assured by my parents and grandparents that nothing quite so dramatic had gone down, but it was still a matter of some pride to me that events of such cinematic scope and significance had taken place in my grandparents’ building. I wouldn’t say that I became preoccupied with MacArthur, but the slight thrill of his ghostly absence was something I felt whenever I visited them.

Later, studying English in college, I read Banville’s The Book of Evidence, which I had heard was based on the MacArthur murders. I was enthralled by the icy composure and artful self-revelations of its murderer-narrator, Freddie Montgomery, the details of whose life and crimes bear an unmistakable resemblance to MacArthur’s. Montgomery is at once despicable, charismatic, depraved, and, somehow, strangely ordinary. Part of the greatness of the book was the way in which you identified with him even as you were utterly appalled by him; he was an Everymonster, part Underground Man and part Humbert Humbert. And he was also Malcolm MacArthur, at several imaginative removes – subjected to the simplifications and elisions of media coverage, to the elaborations and refinements of Banville’s imagination, and, finally, to the preoccupations and preconceptions of my own. I later went on to write my PhD thesis on Banville’s novels, and I must have read The Book of Evidence seven or eight times. Whenever I would see something about MacArthur in the newspapers, fiction and truth would become confounded, and it would be Freddie Montgomery who I would picture on day release, enduring the abuse of passing strangers who would put down their shopping bags to insult him on the streets, to call him a monster, to tell him that if there were any justice in the world he would never be allowed to walk among them.

When I would read The Book of Evidence (or Ghosts, or Athena) I would sometimes find myself wondering what MacArthur might have made of a particular passage, or whether he would have recognized something of himself in the character that both was and was not him. Surely he must have read these books. (He is a well-read man, apparently; a man who bludgeoned a young woman to death with a hammer, yes, and who shot a stranger in the face, but a man of no little cultural refinement nonetheless. In an interview I read a few years ago, Banville told a story about an acquaintance of his who once picked up the last copy of the Times Literary Supplement in a newsagent near Mountjoy prison, and who took it to the counter only to be told that it wasn’t for sale, that it was to be sent up to the prison for Mr. MacArthur, who had a weekly standing order.) There’s one particular moment in The Book of Evidence that forces me, whenever I read it, to imagine what MacArthur’s reaction to it might be. It comes at the very end of Freddie’s long monologue of ambiguous self-recrimination and stylish equivocation, equal parts confession and performance. Sergeant Hogg (whose name gestures toward the author of Confessions of a Justified Sinner as well as to the standard porcine term of cop abuse) walks into Freddie’s cell and hands him a grubby sheet of paper. This, he announces, is Freddie’s confession. Freddie is utterly baffled. “These,” he protests, “are not my words.” Hogg shrugs, telling him to suit himself – he’s going down for life either way – and goes back to finish his dinner. Freddie is left to peruse this “confession,” and in it he sees a version of himself that he does not recognize, but which he nonetheless knows to be true: “It was an account of my crime I hardly recognised, and yet I believed it. He had made a murderer of me […] I was no longer myself. I can’t explain it, but it’s true. I was no longer myself.”

I wonder whether this might be an ironically inverted reflection of what Banville sees himself as doing with (or to) MacArthur here, or of how he envisages him experiencing it. The Book of Evidence is an imagined account of MacArthur’s crimes, one that makes him seem more human, and thereby both more and less terrifying. Within its pages, MacArthur is no longer himself, and that transformation somehow seems to carry over into the real, non-fictional world. There’s a certain kind of paradox here. By transfiguring him into a fiction – by fleshing him out, as it were, into a character – Banville somehow makes MacArthur seem more real, more believable; and yet to actually see him, to walk past him and make fleeting eye contact with him, was an unsettling experience, as though I had encountered the manifestation of a fiction. It was strange enough to chance upon this fabled murderer in a tweed jacket, who had once hidden from the law in the home of the country’s most senior legal officer, separated from my grandparents by a few inches of interior wall. But the simultaneous experience of seeing, and being seen by, a character from a novel I had spent so much time reading and thinking and writing about was somehow stranger still. Of course, Malcolm MacArthur is not Freddie Montgomery. He is a terribly real person, whose actions and whose guilt are likewise real and terrible. I know this, and yet, in some vague but significant sense, I don’t know it at all. Fiction and truth can inhabit the same places at once, and the same bodies.