by Archer Mayor
“Finally,” Eric added, “you should know that we’ve been in touch with David throughout our research. In some cases, while he’s obviously capable of extracting DNA and is much better at handling evidence than we are, we have a lot more data available to us. Without getting complicated, that just means that we’ve been exchanging e-mails about DNA patterns and whatnot that have been very helpful to both parties.”
Shepard somewhat impatiently moved to another slide. “First, the bad news: There were a couple of things that simply gave us nothing of note.” He punched through two slides as he spoke. “The young man’s clothing—Bobby Clarke’s. There was mention in the paperwork that perhaps the killer had placed the body behind the wheel of the truck, thereby depositing some trace evidence on Bobby’s pants and coat. I had no luck at all there, I think because whoever attacked him wore gloves. It’s getting cold up north, no?”
Joe nodded mournfully, remembering David making the same observation days earlier. “Yes—especially at night.”
Shepard appeared unfazed. “The second dead end, so to speak, was Mary Fish’s purported suicide note. You already know that it matched neither her personal printer nor the one in her office; all we could tell was that it came from someone else’s.”
“That having been said,” Eric amended, “we did capture its fingerprint, scientifically speaking. If you ever do come across the printer you think produced this document, we should be able to match the two.”
Shepard’s face lit up at the suggestion. “Yes, of course,” he said. “And that’s true for much of what we’re laying out for you. A good deal of this amounts to snapshots taken of members of a crowd—it will be up to you to connect the picture to the right human being.”
“Understood.” Joe nodded.
“What about the Scotch bottle found on the floor of Bobby’s truck?” Lester asked. “Isn’t that a dud? Our guys at the crime lab said it had been wiped clean.”
Eric beamed. “Yes, but with what?”
Shepard interrupted. “That’ll come later.” He pointed at the laptop. “I don’t want to get out of order.”
Eric Marine couldn’t stop himself. “He used a dirty rag,” he whispered loudly and in a rush, at the same time waving on his colleague and urging, “Okay, okay. Carry on.”
Shepard moved to the next image. “Let’s keep with the victims and address the drops of blood later. Chronologically, that means Doreen Ferenc to begin with.” The slide showed the fragment of Doreen’s nightgown surrounding the knife gash.
“Having just said what I did about staying in order, I’m going to make an exception with her underwear and address it later in a different context. As for the nightgown, though, I think Eric told you of the likelihood of particles on the knife blade ending up on the edges of the fabric’s entrance hole.”
Another image showed a huge magnification, although of what, Joe had no idea.
“And indeed,” Shepard continued, “that was the case. I found gunpowder, engine oil, wood dust—primarily oak—and traces of HC2H, in a formulation suggesting oxyacetylene use, since acetylene as a gas would disappear all on its own.”
“Gunpowder?” Lester echoed, just as Joe muttered, “Acetylene?”
“Let me,” Eric dove in, although his colleague had made no effort to speak first. “This part is really for your ears only, since, as scientists, we should restrict ourselves to fact. But I love Vermont, and visit it every chance I get, and I think I’ve gotten a small feel for the place in the process.”
He rested his elbows on the table, emphasizing his keenness. “What Wayne just mentioned strikes me as perfectly reasonable. Joe, do you carry a knife?”
“Sure.”
Eric shifted his attention momentarily. “Lester?”
Les pulled out a pocketknife and displayed it.
“My point precisely,” Eric resumed. “And both of you presumably use your knives for all sorts of purposes—cleaning your fingernails, opening mail, gutting fish, for all I know. Right?”
Both men nodded, getting the idea.
“Well—and this is pure theory, as I said—here I think you have the knife of a man who maybe loads his own ammunition, is familiar with or works on cars and wood processing equipment, and is within proximity to or handles an acetylene torch, all of which could easily involve the use of a knife blade in time of need. A real Vermonter, in other words.”
Lester was scratching his head. “That’s good to hear.”
“When you load ammunition,” Eric persisted, “you sometimes separate individual flakes of gunpowder to achieve an exact measurement, no?”
Les’s expression cleared. “So you use a knife blade. I got it.”
Joe had removed a pad from his breast pocket and was jotting notes to himself.
“There’s a little more,” Shepard told them. “Again, it’s mostly supposition, and unlike Eric, I don’t know Vermont at all. But acetylene is actually more rarely used than people think. Oxyacetylene welding was very popular back when, but arc-based welding has almost totally replaced it.”
“Still used for metal cutting, though,” Joe finished for him.
Shepard smiled. “Correct. I was thinking that very point might help you home in on a target more accurately.”
“Point taken,” Joe thanked him, adding to his notes. “Although we probably have more people clinging to the old ways than you do down here.”
Shepard nodded. “True.” He turned to his computer and advanced the slide show another image.
“This,” he described unnecessarily, “is the electric cord used to hang Mary Fish. It is also—to echo Eric’s thunder—a nice supporting piece of evidence to the theory he just laid out.”
Again, a picture followed, taken on a micro scale too extreme to recognize.
“Here’s where things get interesting to me,” he said. “It turns out that the cord was beyond simply being new; it was virtually unused, meaning that its surface was factory-pristine.”
“I read in a report that Mary’s companion said the old one had worn out,” Joe explained. “They might’ve bought its replacement but never used it.”
“Well, that was good for us,” Shepard said. “Not that we couldn’t have worked with an older sample. It just would’ve upped the challenge.”
“So you got a print?” Les asked incredulously.
“Not exactly,” Shepard explained. “We extracted a little DNA from a microscopic smear—Eric was telling you that we contacted Dr. Hawke and exchanged some data—but we also lifted some minute environmental evidence left behind by the skin oils—evidence that supports what Eric was saying. All this is where the synchrotron and DNA analysis work hand in glove, with the first securing a sweatprint’s physical deposits, and the latter zeroing in on its genetic code material.”
Another close-up picture. “Engine oil matching that left by the knife,” he said. “And again the acetylene signature—both substances that are prone to resisting a quick scrub, unlike gunpowder or sawdust.”
Shepard sat back. “I have to warn you about something, by the way. Remember how you were told that while the synchrotron process leaves a sample untouched, and that the same couldn’t be said for DNA analysis? Well, there was too little of this touch-DNA to save a leftover sample. I was told that all of this was for investigative purposes only, though.”
Joe was already trying to put him at ease. “No, no. That’s fine. Totally understood. Not a problem.”
“All right.” Shepard nodded and moved to the next slide, this one vaguely familiar to the cops, if not in fact intelligible. “This is actually not your standard DNA profile,” he explained. “We had to resort to something a little fancier called Copy Number Variation to compare what little DNA was on the underwear to whoever handled that electric cord last—there simply wasn’t enough material to do otherwise—much less a standard DNA profile. And yes,” he added quickly, “we did run it against Mary Fish’s and Elise Howard’s genetic code to rule them out; it’
s definitely someone else, a male.”
“You found DNA on the underwear?”
“Next up,” Shepard said, smiling. The next slide showed that article of clothing. “At first blush, we were ready to categorize this alongside the suicide note. The comments David left for us indicated the working theory of the false rape, and that the underpants had been pulled down solely for staging. In the old days, that would’ve been it, and little time would’ve been wasted running tests.”
He turned toward them like a happy snake-oil salesman, his eyebrows high and his expression bright. “But no longer. Infrared spectromicroscopy lets us see things we never thought possible. Following the theory of the case, I worked out in my mind how the victim was attacked, laid out, and then positioned, and calculated that only a finite area of the underwear would have been available for the killer to pull down around her ankles.”
As he was speaking, he was showing various aspects of the garment, once again ending up with what looked like a microscope slide. “The key turned out to be the same mineral and chemical signatures that we lifted from the electric cord. Once we found them, we were able to extract more touch-DNA.” He hit his keyboard dramatically with his finger. “And voilà. A profile perfectly matching the Copy Number Variation sample from the Mary Fish scene. Proof that the same man was at least at the scene of both murders. Agreed?”
Joe was momentarily caught off guard, suddenly realizing that Shepard was actually looking for an answer.
“Absolutely,” he blurted. “Incredible work.”
“Sadly,” Eric added now, “I wasn’t able to extract anything beyond gender from either sample. They’re just too small. Still, with any luck, you’ll be able to run this through your state data bank at least and secure a hit.”
“Fingers crossed,” Lester said softly, his inflection betraying his doubt.
“All right,” Shepard resumed, advancing his show with another image. “Down to the last victim, young Bob Clarke. Here, the paydirt was with the supposedly wiped bottle and the truck bumper.” He cut a slightly disapproving glance at his colleague. “Eric already mentioned how, when the bottle was wiped clean, the cloth or rag used exchanged its trace evidence for the fingerprints that it erased. The report I read said that no rag was found at the scene, is that right?”
“Correct,” Joe told him.
“Then we assume, with some small risk of error, that the killer used his own. This assumption is borne out by what we did find on the bottle’s surface.”
“Don’t tell me,” Lester commented. “Oil and acetylene.”
“Among other things, yes,” Shepard agreed, his earlier glee still somewhat dampened by Marine having stolen his surprise. The reaction reminded Joe of how childish humans could be, regardless of their educational achievements, and maybe—sometimes—because of them.
“Other things?” Joe prompted.
Shepard’s eyes widened slightly. “Ah, yes. Well, not surprisingly, a rag kicking around on the floor of a vehicle or even a glove box, if that’s where he kept it, will pick up a lot of microscopic debris. Still”—the prior shine in his eye made a grudging reappearance—“I was able to locate the sawdust. No gunpowder, though.”
Joe smiled broadly, in part to encourage him. “I can live with that. Oak, again?”
“Not only that,” Shepard conceded, gaining momentum, “but mixed in with the oil were minute metallic flakes, symptomatic of the used engine oil found in every car. My guess is that whoever this is used the rag to either wipe his dipstick or to clean around the pan lug when he last changed his oil. The beauty with that is the same as with DNA—once you locate your suspect’s vehicle, we should be able to connect the old engine oil on the bottle to the oil in that car’s engine.”
“Cool,” Lester murmured.
“Which brings us”—Shepard moved to another slide—“to Bobby’s truck. Here, you must pass along my kudos to David Hawke and his staff, who really did an extraordinary job with all of this material, to be honest. But the truck bumper was tricky and especially well done.”
The picture was of the bumper fragment Joe and Lester had brought with them. Shepard pulled a pen-sized laser pointer from his breast pocket and began moving its hot red dot across the image.
“What we noticed on this otherwise unremarkable surface, employing a variety of light sources, was that it had recently been disturbed, I think we can now safely say by the application of a second bumper used to push Bobby’s truck off the road.”
Lester was scrutinizing the picture and clearly seeing nothing at all. “You’ve got to be kidding.”
“Actually, no,” Shepard answered him. “The photograph doesn’t do the evidence justice, to be sure, so it’s not quite as amazing as you might think. In fact, there are a couple of small aberrations visible to the trained naked eye, but I emphasize the word ‘trained,’ which is where David comes in. As you can see, this was not a new bumper, and it had clearly seen better days. He was able to distinguish old injuries from new, which gave us this . . .”
A new slide appeared.
“Which is what?” Lester asked of the chart before them.
“A readout of the deposits on the surface of the bumper,” Shepard informed them. “Again, similarly to most of the samples we’ve been discussing, the assemblage of artifacts constitutes a unique fingerprint of the offending bumper—everything from transposed dirt, soap from a recent car wash, more oil, our friend the acetylene, and sundry other items of little interest either because they’re so common, or because we can’t link them to anything.”
“Acetylene traces were on the bumper?” Joe asked.
Shepard looked at him appraisingly. “Yes. I was struck by the same thing. What do you make of it?”
“That the user of the torch and the car were in proximity,” Joe said, “implying that the acetylene isn’t being used in a commercial environment, but a home one, like a garage.”
Marine smiled. “That’s what we were thinking.”
“What do we do with that?” Les asked.
“Nothing yet,” Joe said. “But I still like it.”
“I ought to add something about the oil in this instance,” Shepard then pointed out. “It’s not engine oil.”
“Oh?”
“It’s much lighter, more refined. I really had to dig around to find an explanation.”
“Did you find one?” Joe asked him.
“Not really.”
Joe smiled. “You said you hadn’t been to Vermont. We use light oil to undercoat our cars, to stave off rust from road salt.”
Shepard laughed. “That’s it. I even found some salt residue.”
“It’s been snowing up there.”
Shepard nodded. “How wonderful. All right, then. There you have it.”
He again sat back in his chair, this time indicating that his role had reached an end. Joe read the body language and expressed his thanks. “Dr. Shepard, this has been incredible.” He cast a look at Eric Marine before continuing. “I know we’re not through—we still have the three drops of blood—but this alone has already given us a huge advantage. The guys back home will hate me when I hand them all this extra homework, but it’s exactly what we were hoping for. Many, many thanks.”
He looked at Marine again as Shepard went to studying his knuckles self-effacingly, but with a pleased expression. “Dr. Marine?”
Eric happily pulled the laptop toward him. “The blood. Let’s hope this will be a kind of cherry on top of Wayne’s ice cream sundae.”
He fiddled with the program briefly and brought up his own set of pictures, all of them charts and graphs that both cops recognized, at least in theory, from past exposure to DNA explanations, often rendered in court to equally bewildered juries.
“As you know,” Marine began, “we were given three samples, one from each murder scene. We didn’t know the order in which they were originally collected by your suspect, so we kept to the same sequencing order we applied to Wayne’s list,
i.e., Doreen’s was Number One, Mary’s, Number Two, and Bobby’s, Number Three. For reasons that I’ll soon explain, this turns out to have been a fortuitous choice.”
Like Shepard before him, he played the keyboard as he spoke, but since the image contents meant even less to the two laymen, they didn’t pay the slide show much attention. Marine didn’t appear to mind.
“Again, as you knew before coming here, none of the DNA extracted from these three samples matched the victims they accompanied, the other two people killed, or each other. They were pure stranger deposits. My objective approach, therefore, was to work from the basis that at least two out of the three did not belong to the killer, unless, of course, there are actually three killers involved, all of whom left blood samples as a form of signature.”
“Oh, Jesus,” Spinney said, half to himself. “I never even thought of that.”
“It’s unlikely,” Eric agreed. “But possible. On the other hand, it doesn’t really alter my findings, and to be honest, I’m speaking more of how I was thinking before Wayne found what he did, which seems to connect all three cases to one perpetrator. Not only that,” he added, “but as you’ll also soon find out, I’m now pretty doubtful that any of the samples belongs to our guy.”
He lit up the screen with something the two Vermonters could understand—a list.
He introduced it by explaining, “I thought about wowing you with some of the magic we do here, and which your crime lab can only dream about. But then I realized you’d have little clue about what I was describing. That’s the reason for the separate report just for David Hawke.
“So”—he pointed at the screen—“I kept it simple. Drop Number One. He’s a male with brown eyes, chances are he’s black and—with consultation with one of my colleagues working on the NASA radiation effects team here on campus—I figure he’s being treated for an aggressive form of cancer.”
Joe let out a laugh. “You don’t have his cell-phone number?”
Marine looked pleased. “It is fun, I will admit.” He then held up a cautionary finger. “But let me say, before Wayne does, that it all comes with a caveat. The methods I used are cutting-edge stuff, some of it controversial, and none of it, as far as I know, admissible in court—except for the gender reading, of course.”