The crime-scene techs in the parking garage extension logged forty-eight footprints going and forty-four coming back. The perp had been confident but wary on the way in, and striding longer on the way out. In a hurry. The footprints were size eleven. They found fibers on the last pillar before the northeast corner. Mercerized cotton, at a guess, from a pale-colored raincoat, at shoulder-blade height, like the guy had pressed his back against the raw concrete and then slid around it for a look out into the plaza. They found major dust disturbance on the floor between the pillar and the perimeter wall. Plus more blue fibers and more raincoat fibers, and tiny crumbs of crepe rubber, pale in color and old.
"He low-crawled," the lead tech said. "Knees and elbows on the way there, and knees, toes, and elbows coming backward. We ever find his shoes, they're going to be all scraped up at the front."
They found where he must have sat up and then knelt. Directly in front of that position, they saw varnish scrapings on the lip of the wall.
"He rested his gun there," the lead tech said. "Sawed it back and forth, to get it steady."
He lined himself up and aimed his gaze over the varnish scrapings, like he was aiming a rifle. What he saw in front of him was Emerson, pacing in front of the empty ornamental pool, less than thirty-five yards away.
The Academy recruits spent thirty minutes in the empty pool and came out with a lot of miscellaneous junk, nearly eight dollars in pennies, and six bullets. Five of them were just misshapen blobs of lead, but one of them looked absolutely brand new. It was a boat tail hollow point, beautifully cast, almost certainly a.308. Emerson called his lead crime-scene tech up in the garage.
"I need you down here," he said.
"No, I need you up here," the tech replied.
Emerson got up to the second level and found all the techs crouched in a low huddle with their flashlight beams pointing down into a narrow crack in the concrete.
"Expansion joint," the lead tech said. "And look what fell in it."
Emerson shouldered his way in and looked down and saw the gleam of brass.
"A cartridge case," he said.
"The guy took the others with him. But this one got away."
"Fingerprints?" Emerson asked.
"We can hope," the tech said. "Not too many people wear gloves when they load their magazines."
"How do we get it out of there?"
The tech stood up and used his flashlight beam to locate an electrical box on the ceiling. There was one close by, new, with unconnected cables spooling out like fronds. He looked on the floor directly underneath and found a rat's nest of discarded trimmings. He chose an eighteen-inch length of ground wire. He cleaned it and bent it into an L-shape. It was stiff and heavy. Probably overspecified for the kind of fluorescent ceiling fixtures he guessed the garage was going to use. Maybe that was why the project was stalled for funding. Maybe the city was spending money in all the wrong places.
He jiggled the wire down into the open joint and slid it along until the end went neatly into the empty cartridge case. Then he lifted it out very carefully, so as not to scratch it. He dropped it straight into a plastic evidence bag.
"Meet at the station," Emerson said. "In one hour. I'll scare up a DA."
He walked away, on a route exactly parallel to the trail of footprints. Then he stopped next to the empty parking bay.
"Empty the meter," he called. "Print all the quarters."
"Why?" the tech called back. "You think the guy paid?"
"I want to cover all the bases."
"You'd have to be crazy to pay for parking just before you blow five people away."
"You don't blow five people away unless you're crazy."
The tech shrugged. Empty the meter? But he guessed it was the kind of insight detectives were paid for, so he just dialed his cell phone and asked the city liaison guy to come on back again.
Someone from the District Attorney's office always got involved at this point because the responsibility for prosecution rested squarely on the DA's shoulders. It wasn't the PD that won or lost in court. It was the DA. So the DA's office made its own evaluation of the evidence. Did they have a case? Was the case weak or strong? It was like an audition. Like a trial before a trial. This time, because of the magnitude, Emerson was performing in front of the DA himself. The big cheese, the actual guy who had to run for election. And reelection.
They made it a three-man conference in Emerson's office. Emerson, and the lead crime-scene tech, and the DA. The DA was called Rodin, which was a contraction of a Russian name that had been a whole lot longer before his great-grandparents came to America. He was fifty years old, lean and fit, and very cautious. His office had an outstanding victory percentage, but that was mostly due to the fact that he wouldn't prosecute anything less than a total certainty. Anything less than a total certainty, and Rodin gave up early and blamed the cops. At least that was how it seemed to Emerson.
"I need seriously good news," Rodin said. "The whole city is freaking out."
"We know exactly how it went down," Emerson told him. "We can trace it every step of the way."
"You know who it was?" Rodin asked.
"Not yet. Right now he's still John Doe."
"So walk me through it."
"We've got monochrome security videotape of a light-colored minivan entering the garage eleven minutes before the event. Can't see the plates for mud and dirt, and the camera angle isn't great. But it's probably a Dodge Caravan, not new, with aftermarket tinted windows. And we're also looking through old tapes right now because it's clear he entered the garage at some previous time and illegally blocked off a particular space with a traffic cone stolen earlier from a city construction site."
"Can we prove stolen?"
"OK, obtained," Emerson said.
"Maybe he works for the city construction department."
"You think the cone came from the work on First Street?"
"There's construction all over town."
"First Street would be closest."
"I don't really care where the cone came from."
Rodin nodded. "So, he reserved himself a parking space?"
Emerson nodded in turn. "Right where the new construction starts. Therefore the cone would have looked plausible. We have a witness who saw it in place at least an hour before. And the cone has fingerprints on it. Lots of them. The right thumb and index finger match prints on a quarter we took out of the parking meter."
"He paid to park?"
"Won't stand up," he said. "Defense will claim he could have placed the cone for an innocent reason. You know, selfish but innocent. And the quarter could have been in the meter for days."
Emerson smiled. Cops think like cops, and lawyers think like lawyers.
"There's more," he said. "He parked, and then he walked through the new construction. At various points he left trace evidence behind, from his shoes and his clothing. And he'll have picked trace evidence up, in the form of cement dust, mostly. Probably a lot of it."
Rodin shook his head. "Ties him to the scene sometime during the last two weeks. That's all. Not specific enough."
"We've got a three-way lock on his weapon," Emerson said.
That got Rodin's attention.
"He missed with one shot," Emerson said. "It went into the pool. And you know what? That's exactly how ballistics labs test-fire a gun. They fire into a long tank of water. The water slows and stops the bullet with absolutely no damage at all. So we've got a pristine bullet with all the lands and grooves we need to tie it to an individual rifle."