“C’mon, Mattie. You get anything off the zipper? You get a profile?”

“I hope inside that thick skull you’ve kept an open mind, Mike. You have a suspect, don’t you?”

Mike feigned indifference and tossed back the hair on his forehead. “Any one of a number of guys, Mattie. I’m in no rush.”

“You might need to think outside the box, if you’re looking for a guy.” Mattie was holding a printout of the DNA results in her hand. She placed it on the countertop near the door. “One of my techs ran this overnight, just as soon as Mercer Wallace brought it in.”

“What’s the problem?” Mike asked, bending over to study the bands that made up the unique genetic profile of a human being.

I could see where Mattie was going the minute I looked at the page.

The sex of the individual whose blood had been examined was encoded in the DNA results. A male donor’s profile was always marked by two peaks that appeared on the line-one representing the X chromosome and the other representing the Y.

“There’s only one peak,” I said to Mattie.

“Let me see,” Mike said, trying to find the telltale image on the page that looked like a hieroglyphic jumble.

“That’s it, Alex,” Mattie said. “No sign of a Y chromosome anywhere in that little speck of blood, my friend. No question whoever cut herself on that zipper is a woman.”

“How long have you known this?” Mike asked, his fist resting on the lab results.

“I just found out this morning. The tech didn’t want to tell me at first.”

“Why not?” Mike said, shaking his head. “We’re losing precious time.”

“She assumed it was a contaminated result,” Mattie said. “Look, that’s the problem when you aren’t exactly doing a blind test. She knew this was clothing from a female murder victim, and that the original case suspect was a male.”

“So she was surprised to have the profile come up as a woman’s?” I asked.

“Yes, surprised also when she found that it didn’t match the DNA of Rebecca Hassett, from the original samples.”

“So what did she do?” I asked.

“Figured it was her own mistake.”

Contamination was an enormous problem-an everyday issue-for forensic biologists in every lab in the country. They sneezed and coughed at their workstations, opened vials of fluids that dripped or became airborne, and, in more instances than prosecutors liked to hear, inadvertently compromised investigative results.

“You mean the tech ran the test again?”

“Of course. And compared it to her own DNA sample.”

Every person who worked in these offices had to provide his or her own genetic profile, so comparisons could be made against results obtained when contamination was suspected.

“Don’t get discouraged so easily. You know what a long shot this was,” I said.

“The last thing I expected to find was a woman’s DNA on the sweater,” Mike said.

“Mattie’s right about the blinders you let yourself wear sometimes. We knew there was no sexual assault. We should be thinking other motives, other killers-and even whether that blood was already on Bex’s sweater before the night of the murder.”

We left Genco’s office and crossed First Avenue to walk to the deli. We ate together at the counter before returning to see whether Jerry Genco had completed his careful study of Bex Hassett’s remains.

“I should know by now to expect the unexpected.”

“That DNA may have nothing to do with the case. The blood wasn’t necessarily deposited on the sweater the day the Hassett kid died.”

Mike unfolded the copy of the Post that he had paid for at the counter. The headline appeared over Brendan Quillian’s mug shot: MASSIVE MANHUNT FOR MISSING MOGUL.

“You’ve got to go back at Trish Quillian,” I said. “How did she know to show up at the cemetery this morning? Think-do we have anything with her DNA on it? Have you told Peterson to get someone to dump her phone? See who’s called in to her?”

“That’s got to be brother Brendan himself.”

“Or Lem Howell, looking for Brendan. He might have spilled the beans. Somebody certainly tipped her off to it.”

“Maybe she’s just dogging Bobby Hassett’s every step,” Mike said.

“She was already sneaking around the cemetery before he got there.”

We showed our IDs at the entrance and made our way back down to Genco.

“Pull up a couple of stools,” he said. “Get off your gimpy foot.”

“You’re not done yet?” Mike said.

“Not quite. I don’t have the luxury of many one-body days.”

Rebecca Hassett’s internal organs were laid out on separate corkboards, on a stainless steel table along the far end of the wall. A foot square and lightweight, the cork allowed the doctors to cut through the parts without dulling the blades of their knives.

“Is her hair good for information at this point?” Mike asked, looking at a glassine envelope that Genco had prepared for the lab.

“Some drugs stay in it-we’ll test for those. Nicotine, for example. Or something like Thorazine, though there was nothing in the history, I take it, to suggest that. But if it’s excessive alcohol-and only alcohol-as the first studies showed, it won’t give us anything.”

“What’s next?”

“I’ve done the spleen and the pancreas. Very decomposed, as I’d expect. I’m working on the kidney now,” Genco said, thoroughly absorbed in the samples in front of him. “Quite an experience you had in court, Alex, wasn’t it?”

“Dreadful, absolutely dreadful. There aren’t words to describe it to you.”

“You ever think they’d have you spending a day in the morgue just to keep you out of harm’s way?”

“A cemetery and the morgue,” I said.

“Mike knows how to show a girl a good time.”

“What do you look for when you’re doing this, Jerry?”

Genco was concentrating on the organs. “The entire point of the exhumation is to examine specimens more carefully than at the autopsy. I dissect each of these things, hopefully for the second time. See? Here’s the incision from the original dissection.”

I looked over his shoulder. He placed his scalpel an inch away from the previous cut and sliced through the liver, spreading it open on the corkboard like a small piece of fruit.

“Unremarkable,” he said. “Nothing of importance.”

I sat back down. Mike was next to me, reading the sports pages of the paper.

“Now the kidney,” Genco said, moving to the next specimen. “Interesting. There’s a small nodule here.”

I got up again. “It’s only of consequence medically, Alex. Not as evidence. This will go to the lab, of course. It’s probably just a benign tumor in the bile duct. We work up microscopic slides of all of this.”

I went back to my stool.

“When are they going to get the point about the need for some good middle relievers? Mariano can’t do it all by himself,” Mike said. “My Yankees pulled out a squeaker last night.”

“Peculiar,” Genco said, bent over the corkboard.

“Wish it was. I’m afraid it’s par for the course this season.”

“Sorry. I meant this is peculiar.”

“What is?” I asked.

“There’s another little lump here.”

“Where?”

“I’ve got the uterus now. Along with the ovaries and fallopian tubes. They’re light pinkish when you’re alive. Sort of darken with the passage of time.”

I stood up again to look.

“There’s a bulge here, where I’m slicing. Do you see it?”

“Not really.”

“Right next to the point of my scalpel.” He adjusted the overhead lamp. “It’s a corpus luteum. It’s a tiny hemorrhagic cyst in the ovary-where the egg popped out during the menstrual cycle.”

“Did the first doctor find it?” I asked. “Should he have noted it?”

Genco shook his head. “Not necessarily, but then if he hadn’t cut exactly here in this same spot, he’d have missed it quite naturally. It’s very small.”

I was fixated on the deft movements of Genco’s hand as he guided his instrument back to the fallopian tubes. I winced instinctively as he made another incision.