The Black Box

variety of tools or attempted to burn it off with acids.
    But the manufacturing of the weapon and the stamping procedure involved in placing the serial number on it in the first place gave law enforcement a better-than-good chance of recovering the number. When a serial number is stamped on a gun’s surface during manufacture, the procedure compresses the metal below the letters and numbers. The surface may later be filed or acid burned, but it very often still leaves the compression pattern beneath. Various methods can be usedto draw the serial number out. One involves the application of a mixture of acids and copper salts that reacts to the compressed metal, revealing the numbers. Another involves the use of magnets and iron residue.
    “I want to start with Magnaflux because if it works it’s quicker and it doesn’t damage the weapon,” Sargent said. “We still have ballistics work to do with this baby and I want to keep it in working order.”
    “You’re the boss,” Bosch said. “And as far as I’m concerned, quicker is better.”
    “Well, let’s see what we get.”
    Sargent attached a large, round magnet on the underside of the gun, directly below the slide.
    “First we magnetize . . .”
    He then reached up to a shelf over the table and took down a plastic spray bottle. He shook it and then pointed it at the weapon.
    “Now we go with Pistol Pete’s patented iron-and-oil recipe . . .”
    Bosch leaned in close as Sargent sprayed the gun.
    “Iron and oil?”
    “The oil is thick enough to keep the magnetized iron suspended. You spray it on and then the magnet will draw the iron to the surface of the gun. Where the serial number was stamped and the metal is denser, the magnetic pull is greater. The iron should eventually line up as the number. In theory, anyway.”
    “How long?”
    “Not long. If it works, it works. If it doesn’t, we go with acid, but that will most likely damage the gun. So we don’twant to do that until the ballistics work is finished. You have somebody lined up for that?”
    “Not yet.”
    Sargent was talking about the analysis that would confirm that the bullet that killed Anneke Jespersen was fired from the gun in front of them. Bosch was confident that it was, but it was necessary to have forensic confirmation. Bosch was knowingly going about this backwards to maintain his speed. He wanted that serial number so he could trace the gun, but he also knew that if Sargent’s oil-and-iron process didn’t work, he would have to slow things down and proceed in proper order. With O’Toole making his PSB complaint, the delay could effectively kill the forward progression of the case—just what O’Toole was hoping to do so that he could bask in the glow of approval from the chief.
    “Well, then, let’s hope this works,” Sargent said, bumping Bosch out of these thoughts.
    “Yeah,” Harry said. “So should I wait, or do you want to call me?”
    “I like to give it about forty minutes. You can wait if you want.”
    “Tell you what, call me as soon as you know.”
    “You got it, Harry. Thanks for the sub.”
    “Thanks for the work, Pete.”
    There had been times in Bosch’s career when he knew the phone number of the Police Protective League’s Defense Assistance Office by heart. But back in his car, Bosch opened his phone to talk with a defense rep in regard to the O’Toole matter and realized that he had forgotten the number. He thoughtfor a moment, hoping it would come to him. Two young criminalists moved through the parking lot, the wind lifting their white lab coats. He guessed that they were crime scene specialists, because he didn’t know them. He rarely worked live crime scenes anymore.
    Before the League number came back to him, his phone started to buzz in his hand. The ID showed a procession of numbers following a plus sign. He knew it was an international call.
    “Harry Bosch.”
    “Yes, Detective, it is Bonn. I have Mr. Jannik on the line. Can you talk with him? I can translate.”
    “Yes, hold on for a moment.”
    Bosch put the phone down on the seat while he pulled out a notebook and pen.
    “Okay, I’m back. Mr. Jannik, are you there?”
    There was what he assumed was a repeat of his question in Danish and then a new voice responded.
    “Yes, good evening, Inspector.”
    There was a heavy accent but Jannik was understandable.
    “You must forgive my words. My English is very poor.”
    “Better than my Danish. Thank you for talking to me,