The Cold Moon

laundering or other crimes.
    “The sand?” Rhyme asked, referring to the obscuring agent.
    “Generic,” Cooper called, not looking up from the microscope. “Sort used in playgrounds rather than construction. I’ll check it for other trace.”
    And no sand at the pier, Rhyme recalled Sachs telling him. Was that because, as she’d speculated, the perp was planning to return to the alley? Or simply because the substance wasn’t needed on the pier, where the brutal wind from the Hudson would sweep the scene clean?
    “What about the span?” Rhyme asked.
    “The what?”
    “The bar the vic’s neck was crushed with. It’s a needle-eye span.” Rhyme had made a study of construction materials in the city, since a popular way to dispose of bodies was to dump them at job sites. Cooper and Sellitto weighed the length of metal—it was eighty-one pounds—and got it onto the examining table. The span was about six feet long, an inch wide and three inches high. A hole was drilled in each end. “They’re used mostly in shipbuilding, heavy equipment, cranes, antennas and bridges.”
    “That’s gotta be the heaviest murder weapon I’ve ever seen,” Cooper said.
    “Heavier than a Suburban?” asked Lincoln Rhyme, the man for whom precision was everything. He was referring to the case of the wife who’d run over her philandering husband with a very large SUV in the middle of Third Avenue several months earlier.
    “Oh, that . . . his cheatin’ heart,” Cooper sang in a squeaky tenor. Then he tested for fingerprints and found none. He filed off some shavings from the rod. “Probably iron. I see evidence of oxidation.” A chemical test revealed that this was the case.
    “No identifying markings?”
    “Nope.”
    Rhyme grimaced. “That’s a problem. There’ve got to be fifty sources in the metro area. . . . Wait. Amelia said there was some construction nearby—”
    “Oh,” Pulaski said, “she had me check there and they weren’t using any metal bars like that. I forgot to mention it.”
    “You forgot,” Rhyme muttered. “Well, I know the city’s doing some majorwork on the Queensboro Bridge. Let’s give ’em a try.” Rhyme said to Pulaski, “Call the work crew at the Queensboro and find out if spans’re being used there and, if so, are any missing.”
    The rookie nodded and pulled out his mobile phone.
    Cooper looked over the analysis of the sand. “Okay, got something here. Thallium sulfate.”
    “What’s that?” Sellitto asked.
    “Rodent poison,” said Rhyme. “It’s banned in this country but you sometimes find it in immigrant communities or in buildings where immigrants work. How concentrated?”
    “Very . . . and there’s none in the control soil and residue that Amelia collected. Which means it’s probably from someplace the perp’s been.”
    “Maybe he’s planning to kill somebody with it,” Pulaski suggested, as he waited on hold.
    Rhyme shook his head. “Not likely. It’s not easy to administer and you need a high dosage for humans. But it could lead us to him. Find out if there’ve been any recent confiscations or environmental agency complaints in the city.”
    Cooper made the calls.
    “Let’s look at the duct tape,” Rhyme instructed.
    The tech examined the rectangles of shiny gray tape, which had been used to bind the victim’s hands and feet and gag him. He announced that the tape was generic, sold in thousands of home improvement, drug and grocery stores around the country. Testing the adhesive on the tape revealed very little trace, just a few grains of snow-removal salt, which matched samples Sachs had taken from the general area, and the sand that the Watchmaker had spread to help him clean up trace.
    Disappointed that the duct tape wasn’t more helpful, Rhyme turned to the photos Sachs had shot of Adams’s body. Then he wheeled closer to the examination table and peered at the screen. “Look at the edges of the tape.”
    “Interesting,” Cooper said, glancing from the digital photos to the tape itself.
    What had struck the men as odd was that the pieces of tape had been cut with extreme precision and applied very carefully. Usually it was just torn off the roll, sometimes ripped by the attacker’s teeth (which often left DNA-laden saliva), and wrapped sloppily around the victim’s hands, ankles and mouth. But the strips used by the Watchmaker were perfectly cut with a sharp object. The lengths were identical.
    Ron Pulaski hung up, then