The Murder Code (22 page)

‘This case can’t be making it any easier for you.’

‘No.’

‘Because this guy strikes at random?’

‘We can’t work out the pattern, so we can’t stop him. While he’s out there, we can’t protect people.’

‘Well then.’ I felt her chin against my collarbone and her breath warm on my neck. Our son, inside her, pressed against my stomach. ‘You know what you need to do, don’t you?’

‘What?’

‘You need to catch the fucker.’

I nodded. All else aside, that much was true.

‘You need to catch him.’

‘H
E’S PLAYING WITH US,’
Laura said.

‘I know.’

‘There is no pattern.’

‘I think you’re right.’

She looked at me, surprised. ‘That’s not what I expected you to say.’

‘No?’

‘Normally, even if you did think that, you’d disagree with me on general principles.’

I shrugged. We were perched at a desk in the corner of the operations room, going through every single scrap of data over and over again. It was tedious work, but I was glad of it. Maybe I was just glad that Franklin wasn’t here today. He was due back this afternoon, but until then, at least his absence had lifted a little of the pressure.

Still. We’d achieved nothing—found no pattern at all. I was becoming convinced there was no success to be had. That the bastard had always been misleading us.

‘When someone’s right, they’re right,’ I said. ‘Even you. I’m beginning to think the letters are a red herring. All this talk of finding a pattern—he’s using it to throw us off track for some reason. To keep us busy. Stretched too thin.’

Laura grunted at that, meaning:
it’s working, then.

The operations room around us was a hive of activity. Phones were ringing constantly, and officers kept drifting in and out, delivering reports and collecting fresh actions. As much manpower as we had, it was nowhere near enough, not for this many crimes, and the atmosphere in the room felt strained and urgent. We were all tired and frustrated. And that, of course, was what he wanted. Regardless of his real motive for the killings—still clinging to the assumption that there was one—he wanted us strung out.

‘It’s not just the pattern, either,’ I said. ‘He’s laughing at us in other ways too.’

‘What do you mean?’

I gestured at the room. ‘Look at what we’re doing. We’re chasing anything and everything, because we have to. And the more data we have, the worse it gets. Do you know the birthday problem?’

‘Oh—more and more, as the years pass.’

‘It’s a maths puzzle. In a room full of people, how many need to be there for it to be likely two of them share the same birthday?’

‘I’m not getting out my calculator, Hicks.’

‘It’s twenty-three,’ I said.

‘Twenty-three?’

‘Yeah, exactly. It seems like it should be more, but that’s the number where two of the people present—any two of them—are likely to have the same birthday.’

‘Your point? Wait. No, I get it.’

‘Exactly.’

It wasn’t just that every individual victim needed to be scrupulously investigated in their own right—although that took enough time in itself—but the results also needed to be examined across the entire breadth of the investigation. With this many victims we were
bound
to find connections eventually. And we had. Marie Wilkinson, for example, was known to one of the women who worked in the launderette with Vicki Gibson. She had been a regular customer, and it was probable that the two women had met at some point. We were sure it was a coincidence, but it had still needed investigating. Nothing. Similarly, Sandra Peacock had often gone to Santiago’s, where John Kramer had worked as a bouncer. Was that important? It turned out that no, it didn’t seem to be. But we had to waste time looking into it anyway.

The missing-persons reports and the unidentified victims in the video just added extra complications. We thought we had two of them pinned down, and a potential ID on a third, but we couldn’t be sure. So did we run with that data or not? Obviously we had to. Obviously we wouldn’t know if we were right even if we did find something. Which we had not.

‘It’s a fucking arms race,’ I said. ‘That’s what we have here. We only need him to make one mistake; that gets more likely with every murder. But the more he
doesn’t
make one the busier we are and the harder it’ll be to spot when he does. Perhaps he already has.’ I picked up a file of reports and dropped it on the floor. ‘And we’re too lost in fucking paperwork to see it.’

Laura shook her head, then reached down and picked up the file and put it back on the desk on top of all the others.

‘If there is a pattern,’ she said, ‘we’re going to find it.’

I sighed. ‘What time is this woman coming in?’

Given that I was in a relationship with a scientist, I suppose I should have known better than to have a stereotypical view of what one would look like. But still, I had certain expectations of the mathematician we’d arranged to see. She would be serious and austere. Logical and businesslike. Somewhat
grey
.

And as Professor Carol Joyce was shown into the small office, I realised I’d been more or less spot on. She was in her fifties, silver-haired, with rough and lined skin, wearing brackets around her mouth. But there was also an air of casual authority to her that was quite striking. I imagined that to make it as a woman for so long in academia required a degree of toughness. She looked no-nonsense. I had little doubt that every single second of this meeting would be billed to expenses, right down to the bus ticket across town.

‘Detectives,’ she said.

We all shook hands, and then she shrugged off an expensive handbag and thin coat, hanging both over the back of the chair across from us.

‘Thank you for coming,’ I said as she sat down.

‘Not at all. Apart from anything else, I’m curious.’ She looked around the small room, seeming almost amused by her surroundings. ‘I’ve never been in a police station before. Not once.’

‘Is it living up to your expectations?’ I said.

‘So far.’ She glanced at me, still apparently amused. ‘What can I do for you?’

‘Well, we’re hoping you can help us. We have a code we need to break. A possible code, anyway.’

‘How fascinating.’

I slid a sheaf of papers across the desk to her, and she lifted them with elegant hands, peered for a moment, then reached down and retrieved a glasses case from her handbag. The case
pocked
shut, then she hooked on small circular spectacles and peered again, a little more successfully.

‘Before we discuss any of this, I should explain that everything in there is confidential.’

She didn’t look up, but raised an eyebrow. ‘Would you like me to sign something?’

‘Not at all. We can’t, of course, stop you mentioning our conversation, but we’d appreciate it if you didn’t. The fact is you’d possibly be putting lives at risk.’

‘You don’t have to worry. And anyway, I think I’ve already guessed what this is about.’ She looked up. ‘It’s the murders, isn’t it?’

I smiled non-committally.

‘That’s fine.’ Professor Joyce waved a hand vaguely. ‘I don’t expect you to confirm it. I remain curious, though. I’ve never been approached for something like this before, and I’m not sure how I can possibly help you. I suppose it depends on what you feel comfortable telling me.’

‘Let us just say,’ I ventured, ‘we have evidence suggesting there is a design behind the data you have there. I can’t tell you why we suspect that to be the case. But we are hoping that if there is a pattern, you might be able to spot it better than we can.’

‘Let’s see, then.’

She turned the first page. As she worked her way through, I did my best to explain the data we’d collated. One of the problems was that we weren’t even sure what kind of pattern we were looking for, so everything was potentially important. We’d included as much as we could think of.

The hardest thing had been to decide on identifying the victims. We didn’t want to do that, but while it was unlikely, it remained possible they
had
been individually targeted. In the end, we’d listed the initials. The sex of the victims was M or F. Then, obviously, there was age. A basic physical description. We’d listed the dates and approximate times of each attack, along with the period between murders. The numbers of victims on the same night. Location—for the victims we had found—was described in various ways, including GPS co-ordinates and standard map references.

Professor Joyce read through all of it, her face betraying nothing. After a couple of minutes, she looked up.

‘May I take this away with me?’

‘Of course.’

‘Because I can only give you my very basic first impressions from a brief look-through now. What I’d like to do, ideally, is feed the data into some of the programs we have in the department—code-breaking programs, essentially—and see what they come up with.’

‘That sounds fantastic,’ I said. ‘Does anything strike you at first glance?’

‘I’m not sure. You don’t have to answer this, but the evidence you have that there is a pattern—what is it?’

I glanced at Laura. She shrugged.

Your call, Hicks.

‘It’s not conclusive,’ I said. ‘We have some reason to believe the data isn’t random. It’s an attempt to
look
random. Like a computer algorithm. A … pseudo-random number generator?’

‘Yes, I’m familiar.’ Professor Joyce pursed her lips. The lines around them deepened. They looked a little like scars, formed by a lifetime of perusing problems. ‘What do you know about them?’

I felt a little helpless.

‘They’re complex computer programs that generate a string of data. You have one number, say, and you do something to it to generate the next. Add five, or whatever. And so on. If you know the “add five” rule, you can predict the next number.’

‘Basically, yes, though it’s not quite so simple. You have to bear in mind the code can be very complex. It’s not just “add five”—that’s obviously too predictable.’

‘Okay.’

‘Backtrack a little, though, and let’s deal with numbers. How do you form the first number in the sequence?’

I remembered the letter. ‘It’s usually something unique. The date and time setting, for example.’

Professor Joyce nodded. ‘Yes, that’s right. If the sequence began at a different time, it would be very different, even though it followed the same rule. If you add five to one, you get six. If you add it to eight, you get thirteen. Same underlying rule, different sequence. You see?’

‘The numbers in the code aren’t set? They depend on the first … variable?’

‘That’s right.’

I rubbed my forehead.

Professor Joyce looked at me sympathetically.

‘What I’m really saying, Detective, is that whatever the code here might be, the first variable is probably the most interesting.’

‘Right.’

She was telling us we should concentrate on the first victim: Vicki Gibson. A pattern might explain where the
next
victims came from, but he needed a reason to have started where he did. So what was his secret? The problem was that we’d explored every corner of Gibson’s life and found nothing to go on. And then there were the letters.

I still don’t know quite when it will begin.

That is why it’s going to work.

Laura said, ‘Nothing leaps out at first glance, though?’

‘No. That’s why I asked what evidence you had to suggest there even was a pattern here to be found.’

My heart sank a little. Professor Joyce must have seen it on my face.

‘But I wouldn’t expect to see anything obvious. If I could spot a pattern in this in ten minutes, then you would have done too. And there is a great deal of data here: variables of different types. All I can really see immediately are the clusters.’

‘The clusters?’

She looked a little awkward. ‘The … well, the
incidents
that occur together.’ She gestured to the data representing the murders of Kramer, Peacock and Collins: victims three, four and five. ‘Here, for example. These variables are clustered.’

Same date, same location.

‘Okay,’ I said. ‘Go on.’

‘My academic speciality is codes: the making and breaking of them. When you’re constructing a code, the aim is to make something as indecipherable as possible, and there are very sophisticated ways of doing that, involving prime numbers. It’s possible to encode a message, for example, in such a way that it’s practically impossible to break without the key.’

‘That doesn’t sound good.’

‘No, but I don’t think that’s what’s happening here. A much simpler way of coding a pattern is to include static through it. Do you have a pen?’

I passed her one. She leaned over and, without standing on ceremony, scribbled a line of text across the top of the sheet in front of her.

‘There,’ she said. ‘What does that say?’

I turned the sheet round.

HITCICB5MK3X7S38P

‘I have absolutely no idea.’

‘It says “Hicks”. If I wanted to send that to someone for them to read, they’d need to know the following rule: start at the beginning, and whenever you encounter a consonant, completely disregard the next three symbols.’

I read it again, mentally crossing out.

‘I just did that off the top of my head,’ she said. ‘Obviously you could make it far more complicated. After a vertically symmetrical consonant, like “H”, ignore only the next two. And so on.’

‘Okay. So the clusters are … the bits you ignore?’

‘The static, yes. The letters of “Hicks” are all there. They’re even in the right order, plain to see. What makes the sequence
appear
random and meaningless is the clusters of static in between the letters. I just picked those additional symbols at random. They mean nothing.’

They mean nothing
…

Christ. I pictured our killer waiting by the estate that night for whoever came along. Had those murders been part of the pattern he was daring us to find? Or was it just static, obscuring the secret from us?

‘So it’s possible,’ I said slowly, ‘that not all this data is even relevant? That any pattern we’re looking for might only be part of it?’