by Ashley Dyer
But it was a botanist who had given them a more likely explanation: the Thorn Killer had swapped an imperfect tool for something more sophisticated.
Only a few members of the investigatory team were in the know that the Thorn Killer used thorns from a shrub that grew in millions of gardens across the country, and so far they had managed to withhold that information from the general public.
Hayley Evans’s body had been found in June, and two months after that, Ruth Lake and Greg Carver were heading back up Brownlow Hill toward the biological institute. Dr. Grace Furlong, the botanist who had made the original identification, had been working on samples extracted from Hayley Evans. It was the end of August, hot and humid. Heat bounced off the car park tarmac, doubling the effect of the late summer sunshine, and Ruth shrugged off her jacket as soon as she was out of the comfort of the car’s air-conditioning.
“She didn’t say what this was about?” Carver said.
“Just that it was ‘significant,’” Ruth said.
The place was quiet, and they had to walk around to the front of the building and then buzz to gain access to reception. Dr. Furlong arrived in under a minute. She was small and spare, with curly black hair turning to gray, and an energy that seemed to spark off her. She showed them through to the lift, thanking them for coming in person.
“It sounded important,” Carver said.
“I believe it is,” she said, nodding emphatically. “Please—come through.” She led them to a small laboratory. Among other paraphernalia, an e-tablet attached to the housing of a digital microscope displayed a slide showing stacked tubular structures, stained pinkish red.
“This is the thorn?” Ruth asked.
“This,” said Dr. Furlong, “is a longitudinal section—that is to say, cut lengthwise—through a minute fragment of the Berberis stenophylla thorn we identified from Ms. Tredwin’s skin tissues. The pink-stained structures are woody fibers.”
“Okay . . .” Carver said.
Dr. Furlong deftly removed the first slide and replaced it with another, quickly focusing the image. “Now, this is a fragment of thorn that we were sent from the most recent victim.”
Ruth Lake and Greg Carver stood shoulder to shoulder, examining the image projected from the microscope onto the eight-inch tablet screen.
“This is the same magnification?” Ruth said.
“It is—” She seemed delighted by the question. “Magnification two-twenty.”
“These fibers look darker, more densely packed.”
“Mm-hm?” The academic peered into Ruth’s face, her eyes bright, inquisitive.
Ruth sensed that Carver was becoming irritated by the drip-drip of information, but for her own part she was loving it. Being back in the lab reminded her of all the things she had relished about her former work as a CSI. “So . . . this is from a different plant?” she ventured.
The academic smiled, nodding encouragement. “Indeed it is.” She scooted along the bench to a stereo microscope and invited them to take a look. Unlike the digital microscope, the stereo mic was designed to look at whole specimens under comparatively low magnification. This one was set to x15. There was no projector for this microscope, so Ruth went first.
“I’ve mounted examples of the two thorns side by side,” Dr. Furlong said.
Ruth adjusted the focus: the thorn on the left was relatively short and slightly hooked, orange tinted at the tip. She recognized it as Berberis stenophylla—the thorn their killer had used on the first two victims. The other was darker, more woody, four times the length of the berberis thorn and dagger straight, with a wicked point.
“That looks vicious,” Ruth said, stepping back to let Carver peer down the lens.
Dr. Furlong raised an eyebrow. “Doesn’t it?”
She moved to a table nearby and handed a long plastic container to Ruth. Inside was a thin, russet-red branch, about the length of her forearm, but only the thickness of her finger.
“This is Pyracantha angustifolia—the firethorn,” Dr. Furlong said.
Ruth lifted it out of the box. Vivid clusters of fire-red berries clung to the stem, among glossy green leaves, and thorn-laden side shoots broke from the main stem. The thorns, three centimeters long, appeared at intervals along the twig, and at such varied angles that it was almost impossible to handle the thing without being stuck painfully.
“So this is what he used on Hayley Evans?” Carver said.
“DNA analysis confirms it,” Dr. Furlong said.
“Why switch?” Carver frowned at the branch. “Convenience?”
Dr. Furlong tilted her head, but didn’t offer an opinion.
“Is this thing rare?” Carver asked.
“Angustifolia is less commonly grown in the UK than berberis and isn’t as popular as other pyracantha species.”
“I can hear there’s a ‘but’ coming.”
Dr. Furlong dipped her head in apology. “It is widely grown, and readily available.”
So it wouldn’t help them to narrow the search to a particular location.
Still examining the branch, Ruth spiked herself on a thorn and winced. “Maybe he just wants to inflict more pain?” she said, sucking blood from her finger.
“I couldn’t say,” Dr. Furlong said. “But I did do a couple of quick practical tests—a pyracantha thorn is far less likely to bend or break than berberis when pushed into a substance of similar resistance to human skin.”
“So we have a pragmatic serial killer, honing his skills, improving the tools of his trade,” Ruth murmured, turning the branch cautiously in her fingers, focusing on a long side shoot. “Speaking of which . . .”
The side shoot ended in a five-centimeter terminal thorn.
“Nasty-looking thing, isn’t it?” Dr. Furlong said.
Ruth tested it with the tip of her index finger; it was sharp.
“What are you thinking?” Carver said.
Ruth cast a glance around the lab and spied a pair of pruning shears. “May I?”
Dr. Furlong handed them to her and Ruth clipped the side shoot off the main stem. It was about fifteen centimeters long, with four lateral thorns plus the one at the tip.
“If I take these off . . .” She rotated the shoot, trimming off all the lateral thorns, leaving just the evil-looking spike at the end of the stem. Then she turned it point down and gripped it between her thumb and forefinger, like a pen.
“You’ve made yourself a stylus,” Carver said.
Dr. Furlong laughed. “Ingenious.”
Carver didn’t seem to approve of the academic’s enthusiasm for the killer’s choice of murder weapon, but that was because he was a cop, and not a scientist.
“It’s a comfortable grip,” Ruth said, handing it to Carver to try. “He’d have much better control of the depth of puncturing—which could explain why Hayley’s tattoos have less ink bleed.”
“You might also want to speak to a toxicologist,” the botanist said.
“Because?” Carver asked.
“You mentioned in your lab request that the victims had died of asphyxia.”
Carver lifted his chin, acknowledging the fact.
“The genus Pyracantha produces hydrogen cyanide—in small quantities, and mainly in the berries,” Dr. Furlong said. “Nevertheless, it’s worth noting—because cyanide can cause respiratory failure—even death.”
Carver looked at Ruth. This felt like an important moment, even a turning point. Standard tox screens after a suspicious death tested for a fairly narrow band of commonly used poisons. They could take weeks, or even months, to search for more obscure toxins, and every time the lab performed a test it used up some of the victims’ sample bodily fluids, so they had to be selective. This new information gave the analysts a specific toxin to look for, an area of focus.
As it turned out, there was bad news even before the toxicologist began the screening process. Hydrogen cyanide was only detectable in a body for two to three days postmortem, he told them. There was a possible
ray of hope from a recent study that had identified raised levels of a chemical called ACTA in the liver tissue of HCN poisoning victims. This chemical, he said, remained in the liver tissue for weeks or even months, so it could be used as a stable biomarker.
But once again, their hopes were dashed: although the victims’ livers did show signs of inflammation, ACTA levels were normal.
When the fourth victim, Jo Raincliffe, turned up in September, Carver had asked the pathologist to look immediately for physical signs of hydrogen cyanide poisoning, and to include it in the initial tox screen; he even got permission to fast-track the results. But the tests came up negative.
Knowing that the Thorn Killer had crafted a new and more accurate tool from the pyracantha stems should have told them something about his methods and his psychology, but all it had proved in the end was that he was adaptable.
Chapter 10
By seven a.m., Ruth had made a list of lab tests they were still waiting for and fired off e-mails requesting updates. The holiday period slowed everything down, even for a high-profile case like theirs. She’d held off pestering the lab during Christmas week, but this was January 2; the holiday was officially over, and she felt no need to hold back. First on her wish list were the remaining toxicology screens. Even though the pathologist had ruled out cyanide as the means of asphyxiation, the fact that there were no signs of struggle or physical trauma on any of the bodies had convinced him that some form of neurotoxin had been used. He had yet to determine what that was, and how it was administered.
Only days before he was shot, Ruth had gone to DCI Carver with a question: Since the killer was so hung up on the tattoos, what were the chances he had injected poison mixed with the ink he used to tattoo the victims?
She had spoken to Darshan Singh, a toxicologist with whom she had worked in her CSI days, and he had liked the idea. Poison applied to the outer layers of skin via relatively shallow puncture wounds would work more slowly than an injection into a vein. But to have any chance of isolating toxins he would need skin tissue from the most recent tattoos on Kara. Carver had okayed the samples and the cost of tests. Tox analysis could be grindingly slow, but she dropped Dr. Singh an e-mail anyway, asking for an update, then turned to Carver’s notes on police interviews of Kara’s drama school friends.
Pinpointing when and where a person was last seen gave you a target group to talk to. Interviewing witnesses, Ruth always hoped to hear the words, “It’s probably nothing, but . . .” That phrase always sent a shiver of anticipation down her spine. A throwaway comment, an apparently unimportant occurrence, could be the crucial spark to reignite a case that was going cold—could even point the way to the primary scene, yielding all the evidence that had eluded you up to that moment.
Carver had summarized every witness interview from the team of detectives assigned to the case, highlighting commonly used phrases in a neon rainbow of colors, as though working to some kind of language pattern analysis of his own design.
“Bloody hell, Greg,” she murmured. It was a wonder he’d ever found time to sleep.
He’d highlighted one phrase in Day-Glo pink: “Kara was reserved and private.”
Carver had written in the margin, “Why ‘reserved’—why not ‘quiet’ or ‘shy’?” Later in the document, as the phrase came up again, he’d jotted a note—“Rehearsed?” A half page down, he had written, “The party line?!!”
The interview transcripts went on to describe Kara as “private,” that she had “kept to herself.”
His comments degenerating into scrawl, Carver wrote: “Kara delib. isolated?,” then, “Who’s pulling the strings, here?” And later still, “Talk to these little shits again!”
Ruth guessed that Carver was drunk as a skunk when he wrote this—the limits of his patience always had been inversely proportional to his alcohol intake. But she took his point—it did feel like people were struggling for something kind to say about Kara and coming up with platitudes. She needed to talk to Kara’s classmates herself.
She turned to the photographs of Kara, seated under the tree in the grotto, snow on the ground, icicles glittering from the rocks under the waterfall, frost on her eyelashes. Some of that “frost” had turned out to be craft glitter. Snow was forecast for that night, but maybe the killer wanted to be sure of the effect, didn’t want to leave anything to chance.
Unlike most murder victims, too often denied any dignity in death, the Thorn Killer’s victims had been carefully dressed, each left in a restful pose, artfully displayed.
“Artfully”? Really? Ruth examined the pictures of Kara again; it could be a theater set: the ice maiden in her grotto.
Yes, she thought, it was artful.
Back when Ruth was just starting out in her forensic training, one of her lecturers encouraged all of them to dip into The Adventures of Sherlock Holmes. Being a dutiful student, Ruth had read the lot. That was more than ten years ago, and many of the stories had blurred into one, but the odd phrase did stick—one such being, “Singularity is almost invariably a clue.” The fact that their killer took such great care preparing his victims was “singular” in the old-fashioned sense of being unusual. Their killer was no “women-as-playthings” archetype; the way he worked on his victims, and the manner in which he left them afterward, showed a level of care. His behavior contradicted the norms of serial killer behavior. Means, method, and disposal were all “singular.” And the most singular of all these things was that he had selected Kara.
For the first time since she’d met him, Ruth Lake went looking for her new SIO.
It was seven forty-five when she arrived at Canning Place, and DCI Parsons was already in his office, still reading Greg Carver’s files and compiling notes. Parsons was forty, pleasant-looking, as sober suited as an insurance salesman and serious as an undertaker. His desk was laid out with five neat stacks of files, one for each of the victims. Carver’s A4 bound notebook was set in front of him, and a yellow, ruled notepad lay to his right. The page on view was already filled with his close, neat script.
Parsons glanced up at Ruth, a little distracted, or possibly stupefied by the mountain of paperwork he had already tackled. He launched straight in: “I’ve noted some . . . anomalies in my audit.”
Dear God, we’ve got a cop at death’s door and a new murder victim barely cold in the mortuary, and he’s doing an audit.
Ruth had met this type before: always up to the minute on the legislation, keen on protocols and procedures, meticulous with paperwork. Parsons’s type memorized the manuals as if they expected to be spot-tested at any minute. Parsons had a reasonable clear-up rate because mostly the protocols worked. But he was not a risk taker or a betting man, and sometimes in senior policing you needed to be both.
“Some of this stuff just doesn’t tally, Sergeant,” he said, his tone accusing.
Ruth parked her expression in neutral. “Oh,” she said, not inviting further confidences.
He tapped his notepad petulantly.
“Well, what can you tell me?”
“I’m sure DCI Carver will clarify, when he can,” she said, staring past his left ear at an empty picture hook on the wall.
“Didn’t you two talk to each other?”
“Every day, sir.” She remembered what had been on that empty picture hook: a photograph Greg had taken of Striding Edge from the top of Helvellyn in the Lake District. A cardboard box of DCI Parsons’s own photographs had been set on the floor by the desk. It looked like her new DCI was planning to settle in for the long haul.
“I’m waiting for an answer, Sergeant.”
“To . . . what, sir?”
“What the hell was Carver playing at?”
She frowned, still focused on the hook on the wall. “I’m afraid you’ll have to be more specific.”
He gave a snort of disgust. “If you were as obtuse with him, I can see why he would keep you out of the loop.”
She let that one pass, and he sighed heavily. She waited, and final
ly, he looked up, as if surprised to find her still in his office.
“Was there something you wanted, Sergeant?”
“I’ve asked for updates and status reports from the labs,” she said, knowing that this would appeal to Parsons’s need for order.
He gave a begrudging nod of approval.
“And I was thinking about Kara Grogan.”
“Victim five,” he said, glancing at the relevant pile of papers on his desk.
“The student,” she said. “Kara is not the killer’s physical type. Which is an anomaly,” she added.
He glanced at her sharply, his eyes dancing over her face, checking for signs of piss-taking.
She pushed on, giving him nothing. “Kara was like a photo negative of the killer’s type: she was fair-skinned and blond, when all the others—”
“Yes, I’ve read the files,” he interrupted. “I know they were darker, older, and so on. But surely Kara was selected because she looked like Carver’s wife? She was dressed to look like her—the earrings even belonged to Emma Carver.”
“If Kara’s murder was meant as a threat to Carver, you’d think the killer would go for maximum impact—snatch, kill, and dump her fast,” Ruth said. “But he didn’t. The pathologist thinks Kara may have been held for up to five weeks. And he took more care tattooing Kara, using a different dye, dressing her, ‘staging’ her, than he did for all the others.”
“It was personal,” Parsons rationalized. “Carver got too close. He wanted to put Carver—and the investigation—off balance.”
“The first Carver knew about Kara was when he got the call telling him where to find her body.”
“Shock tactic,” Parsons said. “Proves my point.”
“But if the killer wanted to chuck a spanner in the works of the investigation, wouldn’t he let Carver know that a girl was being tortured and murdered? A girl who was nothing like the other victims—a girl who looked like his wife?”
Parsons gave a nod of tacit agreement. “What’s your theory?
“You know how it works with your average woman-hating sociopath—they see what they want, they take it, and then they throw it away. ‘It’ being whoever has (a) the right attributes to feed their fantasy and (b) the bad luck to cross their path,” Ruth said. “But Kara wasn’t selected as a physical type, so it must have been something else about her that got his attention. This guy takes his time, gets to know his victims. Which is why it didn’t matter that Kara was blond and slight when the others were dark and curvy. I think he is selecting people, not ‘objects.’”