“Shoes,” she said simply. “The answer’s shoes.”

“It’s not just about knowing generally what people buy,” Sachs explained. “It’s knowing the specifics about all the vics and the fall guys. Look at three of the crimes. Your cousin’s case, the Myra Weinburg case and the coin theft. Five Twenty-Two not only knew the kind of shoe the fall guys wore. He knew the sizes.”

Rhyme said, “Good. Let’s find out where DeLeon Williams and Arthur buy their footwear.”

A fast call to Judy Rhyme and one to Williams revealed that the shoes were bought mail order-one through a catalog, one through a Web site, but both directly from the companies.

“All right,” Rhyme said, “pick one, give them a call and find out how the shoe business works. Flip a coin.”

Sure-Track won. And it took only four phone calls to reach somebody connected with the company, the president and CEO, no less.

Water was sounding in the background, splashing, children laughing, as the man asked uncertainly, “A crime?”

“Nothing to do with you directly,” Rhyme reassured him. “One of your products is evidence.”

“But not like that guy who tried to blow up the airplane with a bomb in his shoe?” He stopped talking, as if even bringing this up was a breach of national security.

Rhyme explained the situation-the killer’s getting personal information about the victims, including specifics about Sure-Track shoes, as well as his cousin’s Altons and the other fall guy’s Bass walkers. “Do you sell through retail locations?”

“No. Only online.”

“Do you share information with your competitors? Information about customers?”

A hesitation.

“Hello?” Rhyme asked the silence.

“Oh, we can’t share information. That would be an antitrust violation.”

“Well, how could somebody have gotten access to information about customers of Sure-Track shoes?”

“That’s a complicated situation.”

Rhyme grimaced.

Sachs said, “Sir, the man we’re after is a killer and rapist. Do you have any thoughts about how he could’ve learned about your customers?”

“Not really.”

Lon Sellitto barked, “Then we’ll get a fucking warrant and take your records apart line by line.”

Not the subtle way Rhyme would have handled it but the sledge-hammer approach worked just fine. The man blurted, “Wait, wait, wait. I might have an idea.”

“Which is?” Sellitto snapped.

“Maybe he…okay, if he had information from different companies maybe he got it from a data miner.”

“What’s that?” Rhyme asked.

This pause was one of surprise, it seemed. “You never heard of them?”

Rhyme rolled his eyes. “No. What are they?”

“What it sounds like. Information service companies-they dig through data about consumers, their purchases and houses and cars, credit histories, everything about them. They analyze it and sell it. You know, to help companies spot market trends, find new customers, target direct-mail pieces and plan advertising. Things like that.”

Everything about them…

Rhyme thought: Maybe we’re on to something here. “Do they get information from RFID chips?”

“Sure they do. That’s one of the big sources for data.”

“What data miner does your company use?”

“Oh, I don’t know. Several of them.” His voice was reticent.

“We really need to know,” Sachs said, playing good cop to Sellitto’s bad. “We don’t want anybody else to get hurt. This man is very dangerous.”

A sigh floated over the man’s debate. “Well, I suppose SSD is the main one. They’re pretty big. But if you’re thinking that somebody from there was involved in a crime, impossible. They’re the greatest guys in the world. And there’s security, there’s-”

“Where are they based?” Sachs asked.

Another hesitation. Come on, damnit, Rhyme thought.

“In New York City.”

Five Twenty-Two’s playground. The criminalist caught Sachs’s eye. He smiled. This was looking promising.

“Any others in the area?”

“No. Axciom, Experian and Choicepoint, the other big ones, aren’t around here. But, believe me, nobody from SSD could be involved. I swear.”

“What does SSD stand for?” Rhyme asked.

“Strategic Systems Datacorp.”

“Do you have a contact there?”

“Not anybody in particular exactly.” He said this fast. Too fast.

“You don’t?”

“Well, there are sales reps we deal with. I can’t recall their names at the moment. I could check it and find out.”

“Who runs the company?”

Another pause. “That would be Andrew Sterling. He’s the founder and CEO. Look, I guarantee nobody there would do anything illegal. Impossible.”

Then Rhyme realized something: The man was scared. Not of the police. Of SSD itself. “What are you worried about?”

“It’s just…” In a confessional tone he said, “We couldn’t function without them. We’re really…partnered with them.”

Though, from his tone, the spurious verb seemed to mean “desperately dependent on.”

“We’ll be discreet,” Sachs said.

“Thank you. Really. Thank you.” The relief was obvious.

Sachs politely thanked him for his cooperation, drawing an eye roll from Sellitto.

Rhyme disconnected. “Data mining? Anybody heard of it?”

Thom said, “I don’t know SSD but I’ve heard of data miners. It’s the business of the twenty-first century.”

Rhyme glanced at the evidence chart. “So if Five Twenty-Two works for SSD or is one of their customers he could find out everything he’d need about who bought shave cream, rope, condoms, fishing line-all the evidence he could plant.” Then another idea struck him. “The head of the shoe company said that they sell the data for mailing lists. Arthur had gotten some direct mail about that Prescott painting, remember? Five Twenty-Two could have found out about it from their mailing lists. Maybe Alice Sanderson was on a list too.”

“And look-the crime-scene photos.” Sachs walked to the whiteboards and pointed to several pictures from the coin-theft scene. Direct-mail pieces sat prominently on the tables and floor.

Pulaski said, “And, sir? Detective Cooper mentioned E-ZPass. If this SSD mines their data, then the killer might’ve been able to find out exactly when your cousin was in the city and when he headed home.”

“Jesus,” Sellitto muttered. “If it’s true, this guy’s stumbled on one hell of an M.O.”

“Check out this data mining, Mel. Google it. I want to know for sure if SSD is the only one in the area.”

A few keystrokes later: “Hmm. I got over twenty million hits for ‘data mining.’”

“Twenty million?”

Over the next hour, the team watched as Cooper narrowed the list of the top data miners in the country-about a half dozen. He downloaded hundreds of pages of information from their sites and other details. Comparing the various data miners’ client lists with the products used as evidence in the 522 case, it appeared that SSD was the most likely single source of all the information and was, in fact, the only one based in or near New York.

“If you want,” Cooper said, “I can download their sales brochure.”

“Oh, we want, Mel. Let’s see it.”

Sachs sat next to Rhyme and they looked over the screen as the SSD Web site appeared, topped by the company’s logo: a watchtower with a window, from which radiated lines of illumination.

“Knowledge is Power”…The most valuable commodity in the 21^st Century is information, and SSD is the number-one leader in using knowledge to handcraft your strategies, to redefine your goals and to help you structure solutions to meet the myriad challenges you’ll be facing in today’s world. With more than 4,000 clients in the U.S. and abroad, SSD sets the industry standard as the pre-eminent Knowledge Service Provider on earth.