A Winter Grave

Chapter One

The Glasgow High Court of Justiciary was an impressive building, all the more so for being stone-cleaned in the latter part of the twentieth century. A-listed as a structure of historic importance. Very few A-listers, however, had passed through its porticoed entrance. Just a long list of mostly men, in unaccustomed suits, who had gone on to wear a very different kind of attire after sentencing by the Lord Justice General, or the Lord Justice Clerk, or, more likely, one of the thirty-five Lords Commissioners of Justiciary.

Detective Inspector Cameron Brodie had given evidence in various of its courtrooms many times over the years. He was well used to the odour of the justice being dispensed by men and women in wigs and black gowns from lofty oak benches beneath artificial skylights. Justice, it seemed to him, smelled of cleaning fluid and urine and stale alcohol, with the occasional whiff of aftershave.

It was cold outside in the Saltmarket, rain leaking, as it did most days, from a leaden sky. But the heat of legal argument in this courtroom, where a certain Jack Stalker, alias the Beanstalk, stood accused of first-degree murder, had warmed the air to a high level of humidity among all the rainwater trailed in on coats and umbrellas. Stalker sat in the dock, flanked by police officers, a grey man in his thirties with a deeply pockmarked face and a livid scar transecting his left eyebrow. Thinning hair was scraped back and plastered across the shallow slope of his skull with some evil-smelling oil that Brodie imagined he could detect from the witness stand, even above the odour of institutional justice.

Stalker’s lawyer, the elderly Archibald Quayle, was well known for his defence of over five hundred murder cases, more even than the twentieth century’s legendary Joe Beltrami. And despite the sweat that gathered comically in the folds of his neck and chin, he was known by Brodie to be a formidable opponent.

Quayle had wandered away from the big square table beneath the bench where the lawyers and their clerks sat, and now insinuated himself between the jury and the witness stand. He had the condescending air of a man supremely confident in his ability to achieve an acquittal, carrying about him a sense of absolute incredulity that this case had ever come to court.

To Brodie, there was no question of Stalker’s guilt. He had been caught on a high-definition CCTV security camera kicking his victim to death on top of the levee on the north bank of the Clyde near the SEC conference centre.

Quayle turned dark, penetrating eyes in Brodie’s direction. ‘What witnesses did you interview in relation to the alleged assault, Detective Inspector?’

‘None, sir.’

Quayle raised both eyebrows in mock surprise. ‘And why was that?’

‘We were unable to find any. The incident took place in the small hours of the morning. Apparently there was no one else in the vicinity.’

The lawyer for the defence pretended to consult his notes. ‘And what forensic evidence did you acquire that led you to suspect my client of committing this heinous crime?’

‘None, sir.’

The eyebrows shot up again. ‘But your scenes of crime people must have gathered forensic traces from the victim and the crime scene.’

‘They did.’

‘Which matched nothing that you found on the accused.’ A statement, not a question.

‘It took us nearly two days to find Stalker. He had ample time to dispose of anything that might have linked him to the murder.’

‘And how did you find him?’

‘We asked around. He was known to us, sir.’

Quayle frowned. ‘Known to you? How?’

Brodie took a moment before responding. He wasn’t about to fall into Quayle’s trap. He said evenly, ‘I’m afraid that because of the Rehabilitation of Offenders Act 1974, I am unable to say how.’ Which brought smiles around the lawyers’ table, and a glare from the judge.

Quayle was unruffled. ‘Asked around, you say. Asked who?’

‘Known associates.’

‘Friends, you mean?’

‘Yes.’

‘The victim, too, was a friend, wasn’t he?’

‘I believe they once shared the same accommodation.’

‘Flatmates?’ Quayle asked disingenuously.

Brodie paused once more. ‘You might say that; I couldn’t possibly comment.’

Quayle ignored the detective’s flippancy and strode confidently towards his chair. ‘So the only evidence you have against the accused is the CCTV footage that the advocate depute has presented to the court?’

‘It’s pretty damning, I think?’

‘When I want your opinion, Detective Inspector, I’ll ask for it.’ He turned away dismissively, towards the judge. ‘I wonder, my Lord, if I might ask for the court’s indulgence in replaying Production Five A one more time?’

The judge glanced towards the advocate depute, who shrugged. After all, it could only reinforce the case against the accused. ‘I have no objection, my Lord,’ the prosecutor said.

Large screens mounted on all four walls flickered into life, and the murder of the unfortunate Archie Lafferty replayed for the umpteenth time in all its graphic detail. An argument of some kind was in progress. In full view, just across the river, of police headquarters at Pacific Quay, whose lights reflected in the dark waters of the Clyde flowing swiftly by. The levee on the north bank was deserted, except for the two antagonists. Stalker bellowed in Lafferty’s face. You could almost see the spittle gathering on his lips. Then he pushed the other man in the chest with both hands and Lafferty staggered backwards, gesticulating wildly, as if pleading innocence to some savage accusation. Another push and he lost his footing, falling backwards and striking his head on the cobbles. Enough, the pathologist later confirmed, to fracture his skull, though not apparently to induce unconsciousness. Lafferty was more than aware of the kicks that rained in on him from the vicious feet of his attacker, curling up foetally to protect his head and chest. But Stalker was relentless, and when his right foot finally breached the other man’s defences and caught Lafferty full in the face, you could see the spray of blood that it threw off.

The kicking continued for an inordinate and excruciating period of time, long after Lafferty had stopped trying to fend off his attacker and lay spent on the cobbles, soaking up the repeated blows and leaking blood on to stone. Stalker appeared to be enjoying himself, putting all his energy into each repeated blow, until finally he stood breathing hard and looking down on his victim with clear contempt. Lafferty was almost certainly dead by now. Stalker turned on his heel and walked briskly out of shot. The screens flickered and the video came to an end.

No matter how many times he had watched it, Brodie still felt a shiver of disquiet. A silence hung momentarily in the court, before Quayle said casually, ‘That will be all, Detective Inspector.’

Brodie could barely believe it. Quayle was concluding his cross-examination with a replay of the murder, reinforcing his client’s guilt in the minds of every man and woman in the courtroom. Brodie got to his feet, stepped down from the stand and walked briskly to the door.

Tiny was waiting for him outside in the hall. DI Tony Thomson was a man so thin that he didn’t wear clothes, they hung on him. He measured a cool two metres, hence the nickname, and even with his voice lowered, it echoed sonorously around the tiles and painted plaster of this ancient chamber. ‘That didn’t take long, pal. Come on, there’s a pie and a pint with our name on it at the Sarry Heid.’ He turned towards the door leading to the street. But when Brodie made no move to follow, he stopped and looked back. ‘What’s up with you, man?’

Brodie shook his head. ‘Something’s not right, Tiny.’

‘How?’

‘Quayle had me on the stand for less than five minutes, and most of that time he spent rerunning the CCTV footage.’

Tiny frowned. ‘What? He voluntarily showed the jury his client kicking shit out of that poor bastard again?’

Brodie nodded. ‘I’m going back in.’

A few heads turned as the door creaked open and Brodie, followed by Tiny, tiptoed into the courtroom to find themselves places in the crowded public gallery. The advocate depute half turned and offered Brodie a quizzical frown. Brodie just shrugged.

Quayle was on his feet again. ‘My Lord, I have only the one witness. I call Mr Raphael Johnson.’

The court officer returned with the witness in short order and beckoned him towards the stand. Raphael Johnson could have been no more than twenty-seven or twenty-eight years old, with a pimply, adolescent complexion and a mane of thick dark hair that tumbled over narrow shoulders. His T-shirt, beneath a hooded leather bomber, was emblazoned with the faded red logo of some unidentifiable creature breathing fire. His jeans were frayed at the knees and concertinaed over the baseball boots that were once again in fashion. Brodie clocked the nicotine-stained fingers and thumb, his bloodshot eyes and reddened nostrils betraying a likely acquaintance with a certain white powdered substance. Though perhaps Brodie was doing him an injustice. Maybe he simply had a cold, or was recovering from the latest mutation of Covid. It was hard to tell the two apart these days.

He affirmed, rather than take the oath. When asked to tell the court who he was, he called himself Raff, and described his occupation as a computer programmer with special working expertise in audiovisual manipulation.

‘Who is your employer?’ Quayle asked him.

‘I’m self-employed, mate.’

‘And your qualifications?’

‘First-class honours degree in computer science from Strathclyde University.’

‘Tell me about the process of video manipulation known as “deepfake”.’

Raff made a snorting sound. ‘No one calls it that any more, mate. Neural masking. That’s what it’s known as these days.’

‘Tell us about it.’

The advocate depute was on his feet. ‘Objection, my Lord. Relevance?’

Quayle raised a finger. ‘Coming to it.’

The judge nodded. ‘Be quick then, Mr Quayle.’

Quayle nodded and returned to the witness. ‘Mr Johnson?’

‘The technology’s about thirty-five years old. Originated somewhere in the early twenty-tens, with the development of software called GAN.’

‘Which is what?’

‘Well, it stands for generative adversarial network, in which two neural networks use AI to out-predict one another.’

It was clear that no one in the courtroom had the least idea what he was talking about. In an attempt to be helpful, the judge leaned forward and said, ‘I take it we’re speaking of artificial intelligence?’

‘Yes, Your Honour. It’s kind of complicated to explain, but we’re talking about video here, and what GANs did was produce fake videos that you really couldn’t tell were fake. The two neural networks do different things. One of them is a generator; the other we call a discriminator.’

‘And in layman’s terms?’ Quayle was hoping for more clarity.

‘Well, in the early days, GAN was used to superimpose celebrity faces on to the participants in porn videos. Give the generator a few videos, or even some still samples of the celebrity face, and it would seamlessly superimpose it on to the target porn actor. You, or I, maybe couldn’t tell that it had been done. But the discriminator would scan the video and find lots of faults with it. The generator would learn from that, redo the original and let the discriminator scan it again. That process would go on many times until, finally, it was virtually impossible to tell that the video wasn’t genuine.’

Quayle said, ‘And is it still used for that purpose?’

‘Nah.’ Raff shook his thick mane. ‘Nobody does that any more. The software has advanced a lot since then. It has much more sophisticated applications now.’

‘Such as?’

‘Well, you’ve probably read they’ve started making movies with actors who’ve been dead for years, even decades. Big stars of the past. They employ unknown actors to make the film, then superimpose the faces of the dead stars on to them. Bingo! You’ve got Cary Grant playing the latest incarnation of Batman. Or Marilyn Monroe playing herself in a brand-new biopic. They can do the same thing with the voices, too. So...’ He shrugged. ‘CGI went out of business.’

Again the judge leaned forward. ‘CGI?’

‘Computer-generated imagery. It’s how they used to turn a dozen people into a thousand in the movies, or make a scene shot in a studio seem like they were in the Bahamas. Pretty crude stuff by today’s standards.’

Quayle cleared his throat and steered Raff gently back to the subject in hand. ‘This neural masking,’ he said. ‘Just how convincing is it?’

An expression of amusement escaped Raff’s lips in a tiny explosion of air. ‘Mate, you can’t tell it’s not genuine. Unless you have the next-generation AI software — which likely won’t even exist yet — there’s no way to tell that it’s not the real McCoy.’

Quayle nodded sagely, as if he understood every nuance of the technology being described. ‘Are you able to show us an example?’

‘Well, as you know, I prepared a short video by way of demonstration.’

The advocate depute was on his feet again. ‘My Lord...’

But the judge was one step ahead of him. ‘Mr Quayle, you are stretching the court’s patience. This had better be good.’ There was, however, no doubt in anyone’s mind that his lordship was as intrigued as everyone else to see Raff’s video.

‘Thank you, my Lord.’ Quayle nodded towards his clerk and the video screens around the courtroom flickered once more, before the video of the assault on the levee began replaying.

The judge frowned. ‘That’s the wrong video, Mr Quayle.’

Quayle’s smile was almost imperceptible. ‘No, my Lord, it’s not.’

Eyes drawn by this exchange returned to the screens as Jack Stalker turned to confront his victim, and his face was caught in full street-light glare for the first time. Except that it wasn’t Stalker. There was an involuntary collective gasp in the courtroom as DI Cameron Brodie’s superimposed face snarled and pushed Archie Lafferty to the ground before kicking him repeatedly about the face and head. So convincing was it, that there was not a single person in the courtroom who would not have sworn that it was Brodie.

Those same eyes tore themselves away now from the video to glance at Brodie himself, sitting in the public gallery, before returning to the screens, anxious not to miss the moment. Brodie’s face burned with shock and embarrassment. And anger.