"And the profile had to be reworked, Paul. Four years ago, DNA matches were declared with as few as eight loci in common. Now we can't upload a sample unless we've got a thirteen-loci hit."

The reason that DNA had become such a critical tool in identifying individuals is because no two people, with the exception of identical twins, have the same genetic fingerprint. Lab analysis doesn't look at all of a person's DNA, because more than 95 percent of it is exactly the same among every human on earth-two arms, two legs, one head, and so on. What makes us unique is the area of DNA within our chromosomes that is different, and that's called a locus, or location. The more loci that are compared in the laboratory, the more valid the DNA match.

"I assume you hope to find something if you put this information in CODIS. What good is it if it doesn't tell you who he is?"

"Maybe we learn where he's been. I'd settle for that, for starters. Cold hits on serial rape patterns in other cities, a connection to a relative, or a jurisdiction he relocated to for a few years. Rapists this successful don't go dormant, Paul. If he wasn't in jail somewhere-which CODIS also finds out for us-then you can bet he was committing these crimes on somebody else's watch. Maybe the national data bank will tell us where."

I could see the frown lines setting in on Battaglia's face. "So if I follow the commissioner's press conference with one of my own next week-the day you get your first grand jury filing-telling them about my idea to indict the DNA of this monster, you'll give me a briefing on all this, right? Loci and alleles and the rest of the scientific lingo. I'll be able to handle questions on this, in English?"

He was a very quick study. Half an hour in his office before the press corps arrived and the district attorney would be explaining the process of polymerase chain reaction testing and short tandem repeats to them as well as the best serologists would do it on the witness stand at trial.

"This John Doe business stands up on appeal?" he asked.

It was still a controversial technique, used first on a serial pedophile case in Milwaukee and not yet litigated before our appellate jurists. "Our cases were both pleas. It hasn't been tested yet in New York. But the higher courts in Wisconsin, California, and Texas have all upheld it."

"Yeah, well, those judges won't be close enough to this courthouse to see the egg on my face if there's a screwup at 100 Centre Street, will they? You got law for me to read?"

It didn't pay to try to put anything past Battaglia. "I'll give you cases, but yes-there's a slight distinction."

He started to shake his head at me.

"We're solid, Paul. Really. Those other states don't have grand jury systems, so they don't have to go forward by way of indictment. The prosecutors simply issued warrants with sworn affidavits from witnesses and lab techs. It's not that the law is different, it's just an easier way for their lawyers to proceed. Think of it like this, boss. You can announce that you're the first district attorney in the country to do John Doe DNA indictments."

He liked being first at everything. Creating specialized investigative units, taking down international banking firms that no other government agency dared touch, putting deadly drug cartels out of business-originality was a hallmark of his prosecutorial style.

"So it was a good idea, then, for me to think of doing this, wasn't it?" Battaglia said, smiling at Mercer.

He was in a better mood for the second part of my request. "I'm going to need money, Paul. The ME's office will have to retest all of the old samples to conform to the current standard number of loci. We may need to outsource some of them to private labs, which gets pretty expensive. And Mercer's got some interesting approaches that are going to cost us a bit of-"

"Whatever happened to old-fashioned legwork, Detective? Pounding the pavement, spreading some five-dollar bills around town till somebody drops a dime on the perp?"

"Mr. Lincoln's portrait? I haven't broken a case using small change like that since I was in the Academy. This guy beat me first time around, Mr. Battaglia, and I'm damned if it will happen again. He's escalated the violence already."

"I thought this case wasn't completed. He didn't rape her, did he?"

"Only because she fought with every ounce of strength she had to stop him. That's why she was almost killed," I said. "Resisting him-probably because he tried to tie her up."

This predator was fuel for a tabloid feeding frenzy. Not only did he target women in one of Manhattan's toniest residential neighborhoods, long known as the Silk Stocking District because of the wealthy New Yorkers who built mansions there a century ago. He also used panty hose to bind his victims' hands together after he had subdued the women at knifepoint. It didn't matter to the New York Post that most hosiery hadn't been made of silk since the Second World War. Nylon, Lycra, and spandex didn't quite have the same ring on the front page of the morning papers.

The police commissioner's press release tonight would be cause for flooding the area with additional street cops in a precinct already stretched thin by manning security posts on the consulates, diplomatic residences, and high-profile public buildings like art museums that sat within its borders.

"So, no stocking to tie her up this time, but you're willing to go with some drool on the cigarette butt to confirm it's the same man?"

"We don't even know what he did to her, Mr. Battaglia. She hasn't been able to talk yet. The docs have only let me in long enough to ask a handful of questions. I'm not sure how he tried to restrain her. She may have started to kick and fight because of the weapon alone, or because he actually brought out the stocking to tie her. Now that I have the hit from Thaler, I'll go back up to the hospital and see if she's ready to give me more."

"Maybe I can put together an array of composite sketches," I said, "to see whether she picks out our man from the old drawing."

"When I interviewed her briefly, it was before I knew about the DNA match. This time, I can ask her if she saw any panty hose. With or without the hosiery, science will prove it to an absolute certainty."

"Mercer wants me to hire a geographic profiler, Paul. There's a guy in Vancouver who's willing to fly in and-"

"I thought you didn't believe in that profiling mumbo jumbo, Alex."

"I don't. Not the psychological crap. 'You're looking for a guy who had a bad experience with a woman when he was nine, Ms. Cooper. Your rapist probably has trouble expressing himself to women in a normal sexual setting.' 'No kidding, Doc. I'll keep that in mind.' We're not talking about that nonsense, Paul."

"This fellow I've introduced Alex to has solved pattern crimes all over the country. You bring him in and he studies each of the scenes, same time of night, same lighting conditions as when the crimes happened," Mercer said. "Helps us figure out how our perp conceals himself from victims who never see him coming until they've got the key in the brownstone lock. And more important, gives us a clue how he gets away afterwards when we've had the area saturated with police."

"Don't you remember, Paul? Four years back the task force beefed up street patrol, anti-crime units, undercovers on foot and in unmarked cars. They had helicopters on standby, canine on the sidewalk within minutes of each attack. Cops were at subway entrances and cruising in medallion cabs. Even the tollbooths at the bridges and tunnels were doing car checks."

I reached for the poster board, which had been wedged behind one of my file cabinets for the last four years until I pulled it out on our return from the hospital to add the new site to the old pattern. I lifted it onto my desk so Battaglia could see it better and circled the line of pushpins that ran from Annika's building through the locations of the older cases. Every attack had occurred between Sixty-sixth and Eighty-fourth Streets, Second Avenue to the river, two long blocks east of the nearest subway line.