Rhyme wheeled closer and looked it over. There was no store name; the slip had been printed by an adding machine. The ink was faded.
"Won't tell us very much," Pulaski said then seemed to think he shouldn't be talking.
What was he doing here? Rhyme wondered.
Oh, that's right. Helping Sellitto.
"Sorry to differ," Rhyme said stridently. "Tells us a lot. He bought all the items in the pack at one store--you can compare the receipt to the price tags--well, along with something else he bought for five ninety-five that wasn't in the bag. Maybe the tarot deck. So we've got a store that sells duct tape, box cutters and condoms. Got to be a variety store or variety drugstore. We know it's not a chain because there's no logo on the bag or receipt. And it's low-budget since it only has cash drawers, not computerized registers. Not to mention the cheap prices. And the sales tax tells us that the store is in . . . " He squinted as he compared the subtotal on the receipt with the amount of tax. "Goddamnit, who knows math? What's the percentage?"
Cooper said, "I've got a calculator."
Geneva glanced at the receipt. "Eight point six two five."
"How'd you do that?" Sachs asked.
"I just kind of can," she said.
Rhyme repeated, "Eight point six two five. That's the combined New York state and city sales tax. Puts the store in one of the five boroughs." A glance at Pulaski. "So, Patrolman, still think it's not very revealing?"
"Got it, sir."
"I'm decommissioned. Sir isn't necessary. All right. Print everything and let's see what we can find."
"Me?" the rookie asked uncertainly.
"No. Them."
Cooper and Sachs used a variety of techniques to raise prints on the evidence: fluorescent powder, Ardrox spray and superglue fumes on slick surfaces, iodine vapor and ninhydrin on porous, some of which raised prints by themselves, while others displayed the results under an alternative light source.
Looking up at the team through his large orange goggles, the tech reported, "Prints on the receipt, prints on the merchandise. They're all the same. Only, the thing is, they're small, too small to be from a six-foot-tall man. A petite woman or a teenage girl, the clerk's, I'd say. I see smudges too. I'd guess the unsub wiped his own off."
While it was difficult to remove all the oils and residue left by human fingers, prints could be obliterated easily by a brief rubbing.
"Run what you've got through IAFIS."
Cooper lifted copies of the prints and scanned them. Ten minutes later the FBI's integrated automated fingerprint identification system had verified that the prints did not belong to anyone on file in the major databases, city, state and federal. Cooper also sent them to some of the local databases that weren't linked to the FBI's system.
"Shoes," Rhyme announced.
Sachs produced the electrostatic print. The tread marks were worn, so the shoes were old.
"Size eleven," Cooper announced.
There was a loose correlation between foot size and bone structure and height, though it was tenuous as circumstantial evidence in court. Still, the size suggested that Geneva had probably been right in her assessment that the man was around six feet tall.
"What about a brand?"
Cooper ran the image through the department's shoe-tread database and came up with a match. "Bass-brand shoes, walkers. At least three years old. They discontinued this model that year."
Rhyme said, "The tread wear tells us he has a slightly turned out right foot, but no noticeable limp and no serious bunions, ingrown nails or other malades des pieds."
"I didn't know you spoke French, Lincoln," Cooper said.
Only to the extent it helped an investigation. This particular phrase had come about when he was running the missing-right-shoes case and had spoken on a number of occasions to a French cop.
"What's the trace situation?"
Cooper was poring over the evidence collection bags containing the tiny particles that had adhered to Sachs's trace collector, which was a sticky roller, like the kind for removing lint and pet hair. Rollers had replaced DustBuster vacuum cleaners as the collector of choice for fiber, hair and dry residue.
Wearing the magnifiers again, the tech used fine tweezers to pick up materials. He prepared a slide and placed it under the microscope, then adjusted the magnification and focus. Simultaneously, the image popped up on several flat-screen computer monitors around the room. Rhyme turned his chair and examined the images closely. He could see flecks that appeared to be bits of dust, several fibers, white puffy objects, and what looked like tiny amber shells shed by insects--exoskeletons. When Cooper moved the stage of the scope, some small balls of spongy, off-white fibrous material were visible.
"Where did this come from?"
Sachs looked over the tag. "Two sources: the floor near the table where Geneva was sitting and beside the Dumpster where he was standing when he shot Barry."
Trace evidence in a public place was often useless because there were so many chances for strangers unconnected to the crime to shed material. But similar trace being found in two separate locations where the perp had been suggested strongly that it had been left by him.
"Thank you, Lord," Rhyme muttered, "for thy wisdom in creating deep-tread shoes."
Sachs and Thom glanced at each other.
"Wondering about my good mood?" Rhyme asked, continuing to stare at the screen. "Was that the reason for the sidelong look? I can be cheerful sometimes, you know."
"Blue moon," the aide muttered.
"Cliche alert, Lon. You catch that one? Now, back to the trace. We know he shed it. What is it? And can it lead us to his den?"
Forensic scientists confront a pyramid-shaped task in analyzing evidence. The initial--and usually easiest--job is to identify a substance (finding that a brown stain, for instance, is blood and whether it's human or animal, or that a piece of lead is a bullet fragment).
The second task is to classify that sample, that is, put it in a subcategory (like determining that the blood is O positive, that the bullet that shed the fragment was a .38). Learning that evidence falls into a particular class may have some value to police and prosecutors if the suspect can be linked to evidence in a similar class--his shirt has a type-O-positive bloodstain on it, he owns a .38--though that connection isn't conclusive.
The final task, and the ultimate goal of all forensic scientists, is to individuate the evidence--unquestionably link this particular bit of evidence to a single location or human being (the DNA from the blood on the suspect's shirt matches that of the victim, the bullet has a unique mark that could be made only by his gun).
The team was now low on this forensic pyramid. The strands, for instance, were fibers of some sort, they knew. But more than a thousand different fibers were made in the United States annually and over seven thousand different types of pigments were used to color them. Still, the team could narrow down the field. Cooper's analysis revealed that the fibers shed by the killer were plant based--rather than animal or mineral--and they were thick.
"I'm betting it's cotton rope," Rhyme suggested.
Cooper nodded as he read through a database of vegetable-based fibers. "Yep, that's it. Generic, though. No manufacturer."
One fiber contained no pigments but the other had a staining agent of some kind. It was brown and Cooper thought the stain might be blood. A test with the phenolphthalein presumptive blood test revealed that it was.
"His?" Sellitto wondered.
"Who knows?" Cooper responded, continuing to examine the sample. "But it's definitely human. With the compression and fractured ends, I'd speculate the rope's a garrotte. We've seen that before. It could be this was the intended murder weapon."
His blunt object would be simply to subdue his victim, rather than to kill her (it's hard, messy work beating someone to death). He also had the gun, but that would be too loud to use if you wanted to keep the murder quiet in order to escape. A garrotte made sense.
Geneva sighed
. "Mr. Rhyme? My test."
"Test?"
"At school."
"Oh, sure. Just a minute . . . I want to know what kind of bug that exoskeleton's from," Rhyme continued.
"Officer," Sachs said to Pulaski.
"Yes, m' . . . Detective?"
"How 'bout you help us out here?"
"Sure thing."
Cooper printed out a color image of the bit of exoskeleton and handed it to the rookie. Sachs sat him down in front of one of the computers and typed in commands to get into the department's insect database--the NYPD was one of the few police departments in the world that had not only an extensive library of insect information but a forensic entomologist on staff. After a brief pause the screen began to fill with thumbnail images of insect parts.
"Man, there're a lot of them. You know, I've never actually done this before." He squinted as the files flipped past.
Sachs stifled a smile. "Not exactly like CSI, is it?" she asked. "Just scroll through slowly and look for something you think matches. 'Slow' is the key word."
Rhyme said, "More mistakes in forensic analysis occur because technicians rush than because of any other cause."
"I didn't know that."
Sachs said, "And now you do."
Chapter Six
"GC those white blobs there," Rhyme ordered. "What the hell are they?"
Mel Cooper lifted several samples off the tape and ran them through the gas chromatograph/mass spectrometer, the workhorse instrument in all forensic labs. It separates unknown trace into its component parts and then identifies them. The results would take fifteen minutes or so, and while they waited for the analysis Cooper pieced together the bullet the emergency room doctor had removed from the leg of the woman whom the killer had shot. Sachs had reported the gun had to be a revolver, not an automatic, since there were no brass cartridges ejected at the scene of the shooting outside the museum.
"Oh, these're nasty," Cooper said softly, examining the fragments with a pair of tweezers. "The gun's small, a .22. But they're magnum rounds."
"Good," Rhyme said. He was pleased because the powerful magnum version of the rimfire 22-caliber bullet was rare ammunition and therefore would be easier to trace. The fact that the gun was a revolver made it rarer still. Which meant they should be able to find the manufacturer easily.
Sachs, who was a competitive pistol shooter, didn't even need to look it up. "North American Arms is the only one I know of. Their Black Widow model maybe, but I'd guess the Mini-Master. It's got a four-inch barrel. That's more accurate and he grouped those shots real tight."
Rhyme asked the tech, who was poring over the examination board, "What'd you mean by nasty?"
"Take a look."
Rhyme, Sachs and Sellitto moved forward. Cooper was pushing around bits of blood-stained metal with the tweezers. "Looks like he made them himself."
"Explosive rounds?"
"No, almost as bad. Maybe worse. The outer shell of the bullet's thin lead. Inside, the slug was filled with these."
There were a half dozen tiny needles, about three-eighths of an inch long. Upon impact, the bullet would shatter and the pins would tumble in a V pattern throughout the body. Though the slugs were small they'd do far more damage than regular rounds. They weren't designed to stop an attacker; their purpose was solely to destroy internal tissue. And without the numbing effect of a large-caliber slug's impact, these shells would result in agonizing wounds.
Lon Sellitto shook his head, eyes fixed on the needles, and scratched the invisible stain on his face, probably thinking how close he'd come to being hit with one of these slugs. "Jesus," he muttered. His voice broke and he cleared his throat, laughed to cover it up and walked away from the table.
Curiously, the lieutenant's reaction was more troubled than the girl's. Geneva didn't seem to pay much attention to the details of her attacker's gruesome rounds. She glanced again at her watch and slouched impatiently.
Cooper scanned the largest pieces of the bullet and ran the information about the slugs through IBIS, the Integrated Ballistics Identification System, which nearly a thousand police departments around the country subscribe to, as well as the FBI's DRUGFIRE system. These huge databases can match a slug, fragments or brass casing to bullets or weapons on file. A gun found on a suspect today, for instance, can quickly be matched to a bullet recovered from a victim five years ago.
The results on these slugs, though, came back negative. The needles themselves appeared to have been broken off the end of sewing needles, the sort you could buy anywhere. Untraceable.
"Never easy, is it?" Cooper muttered. At Rhyme's direction, he also searched for registered owners of Mini-Masters, and the smaller Black Widows, in .22 magnum, and came back with nearly a thousand owners, none of whom had criminal records. Stores aren't required by law to keep records of who buys ammunition and therefore they never did. For the time being, the weapon was a dead end.
"Pulaski?" Rhyme shouted. "What's with the bug?"
"The exoskeleton--is that what you called it? That's what you mean, sir?"
"Right, right, right. What about it?"
"No matches yet. What exactly is an exoskeleton?"
Rhyme didn't answer. He glanced at the screen and saw that the young man was only a small way into the Hemiptera order of insects. He had a long way to go. "Keep at it."
The GC/MS computer beeped; it had completed its analysis of the white blobs. On the screen was a peak-and-valley chart, below which was a block of text.
Cooper leaned forward and said, "We've got curcumin, demethoxycurcumin, bisdemethoxycurcumin, volatile oil, amino acids, lysine and tryptophan, theronine and isoleucine, chloride, various other trace proteins and large proportion of starches, oils, triglycerides, sodium, polysaccharides . . . Never seen that combination."
The GC/MS was miraculous in isolating and identifying substances, but not necessarily so great in telling you what they added up to. Rhyme was often able to deduce common substances, like gasoline or explosives, just from a list of their ingredients. But these were new to him. He cocked his head and began to categorize those substances in the list that, as a scientist, he knew would logically be found together and which would not. "The curcumin, its compounds and the polysaccharides obviously fit together."
"Obviously," was the wry response of Amelia Sachs, who used to ditch science class in high school to go drag racing.
"We'll call that Substance One. Then the amino acids, other proteins, starches and triglycerides--they're often found together, too. We'll call them Substance Two. The chloride--"
"Poison, right?" asked Pulaski.
"--and sodium," muttered Rhyme, "are most likely salt." A glance at the rookie. "Dangerous only in the case of people with high blood pressure. Or if you're a garden slug."
The kid turned back to the insect database.
"So--with the amino acids and starches and oils--I'm thinking Substance Two is a food, salty food. Go online, Mel, and find out what the hell curcumin is in."
Cooper did. "You're right. It's a vegetable dye used in food products. Usually found in connection with those other items in Substance One. Volatile oils too."
"What sort of food products?"
"Hundreds of them."
"How 'bout some for-instances."
Cooper began to read from a lengthy list. But Rhyme interrupted. "Hold on. Is popcorn on the list?"
"Let's see . . . yeah, it is."
Rhyme turned and called to Pulaski, "You can stop."
"Stop?"
"It's not an exoskeleton. It's a shell from a popcorn kernel. Salt and oil and popcorn. Should've figured that one out up front, damnit." It was a cheerful expletive nonetheless. "On the chart, Thom. Our boy likes junk food."
"Should I write that?"
"Of course not. He could hate popcorn. Maybe he works in a popcorn factory or movie theater. Just add 'popcorn.' " Rhyme looked at the chart. "Now let's find out about that other trace. The off-white stuff."
&nb
sp; Cooper ran another GC/MS test. The results indicated that it was sucrose and uric acid.
"The acid's concentrated," the tech said. "The sugar's pure--no other foodstuffs--and the crystalline structure's unique. I've never seen it milled like that."
Rhyme was troubled by this news. "Send it to the FBI's bomb people."
"Bomb?" Sellitto asked.
Rhyme said, "Haven't been reading my book, hmmm?"
"No," the big detective shot back. "I've been busy catching bad guys."
"Touche. But it'd be helpful to at least take a look at the headings from time to time. As in 'Homemade Explosive Devices.' Sugar's often an ingredient. Mix it with sodium nitrate and you've got a smoke bomb. With permanganate, it's a low explosive--which can still do a lot of damage if you pack it into a pipe. I'm not sure how the uric acid figures but the Bureau's got the best database in the world. They'll tell us."
The FBI's lab is available to handle evidence analysis for state and local law enforcers, at no charge, provided that the requesting agency agrees to two things: to accept the FBI's results as final and to show them to the defendant's lawyer. Because of the Bureau's generosity--and its talent--the agents are inundated with requests for assistance; they run more than 700,000 analyses a year.
Even New York's finest would stand in line like everyone else to get this bit of sugar analyzed. But Lincoln Rhyme had an in--Fred Dellray, a special agent in the FBI's Manhattan office, often worked with Rhyme and Sellitto and he carried a lot of weight in the Bureau. Equally important was the fact that Rhyme had helped the FBI set up its PERT system--the Physical Evidence Response Team. Sellitto called Dellray, who was presently on the task force checking out those reports of potential terrorist bombings in New York. Dellray got on the horn to FBI HQ in Washington, D.C., and within minutes a technician had been recruited to help on the Unsub 109 case. Cooper sent him the results of the analyses and compressed digital images of the substance via secure email.
No more than ten minutes passed before the phone rang.
"Command, answer," Rhyme snapped into his voice recognition control system.
"Detective Rhyme, please."
"This's Rhyme."
"I'm Examiner Phillips down on Ninth Street." Washington's Ninth Street, he meant. FBI headquarters.
"What do you have for us?" Rhyme asked briskly.
"And thanks for calling back so fast," Sachs said quickly. She sometimes had to run interference for Rhyme's bluntness.