Yes. That was it precisely. Mersenne 44. Yes. Yes. Yes.

He picked up his pace now and continued up the street without looking back again.

Chapter 87

IT WAS QUIET at the Fingerprint Analysis Section when I got there. The only person in the lab was one of the civilian staff, an analyst named Bernie Stringer who usually went by “Strings.” I could hear the heavy metal on his iPod blaring away while he worked.

“I hope that’s not priority!” he shouted, and then pulled out an earbud. “Narcotics is already kicking my ass here.” There were two full boxes of slides on the bench next to him.

“I just need some prints off of this,” I said, holding the Coke can up by the lip.

“Tonight?” he said.

“Yeah, actually. Now.”

“Knock yourself out, man. Cyanoacrylate’s in the drawer by the fuming chamber.”

That was fine by me. I like working in the lab every once in a while. It makes me feel smarter, even if printing is Forensics 101.

I went over to the fuming chamber and set the can upright inside. Then I put a few drops of cyanoacrylate, which is really just superglue, on a dish and sealed it all up to heat for a while.

In about fifteen minutes, I had a nice four-print set standing out on the surface of the can. Sampson’s paw print was there, too, but it was easy enough to differentiate, sizewise.

I dusted the ones I wanted with black powder and took a few pictures, just in case.

After that, it was only a matter of lifting them with clear tape and laying them back down on a card for scanning.

“Hey, Strings!” I shouted over. “Can I use your system?”

“Knock yourself out! Password’s B-I-G-B-U-T-Z.”

“Of course it is,” I said.

“Huh? What’s that?”

“Nothing.”

Once I got the prints onto the computer, it took IAFIS about half an hour to spit out four possible matches. A lot of the time, the final comparison is done by eye, which is good. It helps keep the process human.

And it didn’t take long for me to confirm one of the four.

The tented arch pattern on our man’s index finger was fairly distinctive, even as these little puzzles go.

With a few keystrokes, I had his name and record right there in front of me.

He was Stanislaw Wajda.

That explained the accent anyway. He’d been arrested just once, on a domestic assault charge in College Park, Maryland, a year and a half earlier. It didn’t seem like too much to go on.

But, in fact, I’d just stumbled onto a killer.

Chapter 88

AN INITIAL ONLINE search for “Stanislaw Wajda” brought up all kinds of different results. When I filtered for news reports, I got a whole slew of year-old stories about a missing-persons case.

That seemed promising, and I clicked on the first one, from the Baltimore Sun.