Bad blood

40

Mattie’s small office was tucked away at the end of the hall, past the lab in which forensic biologists sat elbow to elbow at their tables, interpreting data that cooked overnight in the robots-the giant machines capable of running dozens of DNA samples at a time.

“I wanted you to see this for yourself, Alex,” Mattie said.

Mike was pacing behind her; three steps in each direction was all that the space allowed. He looked up as I entered, but didn’t bother to greet me. “The bastard would never have had the chance to escape.”

“What have you got now? I hear you did a brilliant job on Trish Quillian’s gob of spit,” I said to Mattie. Mike was talking to her about Brendan Quillian, and I didn’t understand why.

“That’s old news already, Coop. Get with it.”

“Last week, the night of the blast in the water tunnel,” Mattie said, “we were so proud of ourselves for showing off the mobile lab. Getting the crew up there and having results in less than ten hours.”

“The guys did a great job.”

“I think so, too. From bits and pieces of flesh, they matched the two sandhogs from Tobago to items they found in their lockers and their home.”

“Sorry. I never even focused on those men,” I said. “We’ve all been assuming they were caught in the wrong place at a very wrong time, not that they were the targets of the killer.”

“That’s quite possible. Yes, one had tissues in a jacket pocket in the shed. Cut himself on a piece of metal a day or two before the explosion. The other one was identified from his toothbrush.”

“And then there was Duke Quillian,” Mike said, locking his thumbs in the rear pockets of his jeans.

I frowned and looked at Mike for an explanation. “Don’t tell me he wasn’t down there in the tunnel? He was certainly identified, too. Wasn’t he?”

It was Mattie who spoke. “Yes. Duke Quillian is dead. But the day he was identified, it wasn’t actually done by a DNA analysis of his blood.”

“Why not? I thought…”

Mattie spread the reports in front of her. “For one thing, we had the severed digit,” she said, pointing to an eight-by-ten blowup of the large finger with its ragged edge.

“They just scraped skin cells off the surface of it, and of course, they also had a perfect print to match.”

“Duke Quillian had no record. No fingerprints on file with the NYPD. Mike checked that the first day.”

“Yes, but the union required all the sandhogs to be fingerprinted after 9/11. It was mandated as a security issue, for some of the jobs they had to work on near Ground Zero-rebuilding subway stations and such,” Mattie said. “The prints were delivered to the ME’s office within hours of the blast, so that confirmed his death.”

“All that confirmed,” Mike said, correcting Mattie, “is that it would be a struggle for him to use a rotary phone. It was only one finger.”

Mattie shook her head at Mike. “And the dental records. A piece of Quillian’s skull was picked up at the scene. That fragment was also matched to his dentist’s files.”

“So Duke’s dead, right?” I asked.

“Very dead, Alex,” Mattie said. “And I know we never do things fast enough for Mike, but you’ve got to remember the backlog we have. No one else was reported missing, so we knew we had the deceased-our three victims-identified.”

With the expansion of the capability of DNA to solve crimes-well beyond murders and sexual assaults-the lab was inundated with dozens of investigative requests a day, some of them presenting dozens of samples per case.

“Thousands of pieces of skin and tissue were collected in the debris from the tunnel,” Mattie went on. “The techs have been doing extractions on them as fast as they can, in between all the new work that’s brought in every day. They’ve been running samples in the robots. One of my guys got a result yesterday that had him stymied. It didn’t make sense to him, so he brought it to me to discuss last night, after Mercer left.”

“What didn’t make sense?” I asked.

“This-this anomaly.”

“Anomaly?”

Mike leaned over Mattie’s shoulder. “Yeah, Coop. Anomaly. That’s a scientific expression that usually translates as ‘Detective Chapman, you’re screwed.’ Show her.”

There were pages of reports from the various biologists who had worked on the tunnel samples. With the tip of her pen, Mattie pointed to the profiles that repeated themselves on different test results.

“Here’s Tobagan Number One, as we’ve called him.” His tissue fragments had been identified again and again from remains within the blast site.

She lifted her pen and moved to Tobagan #2, making the same point.

“This,” Mattie went on, “is the genetic profile of Duke Quillian. We obtained it, of course, from the skin cells of the finger that Mike recovered on the first day. It matches skin cells from microscopic pieces of flesh that were in the debris. There’s no question that Duke was blown to bits.”

“Then what’s the anomaly?” I asked.

“You can look at every single blood sample-hundreds of them-that we’ve been running these last two days to wind up the investigation. Not one of them-not one drop of blood-matches the DNA of Duke Quillian.”

“You’ve got the man’s skin, but you don’t have his blood?”

“Exactly, Alex.”

“Can you explain-”

“It turns out there is DNA from a fourth person,” Mattie said, wagging her pen in my face. “A different profile that several techs developed. Something that didn’t match to any of the deceased.”

“But there are no other reports of missing persons.”

“Right, there haven’t been any, and it’s actually much easier than that, Alex. It’s the DNA of a woman in this fourth profile,” Mattie said. “One peak only. Again, there’s no Y chromosome.”

“But there were no women working in the tunnel. It’s bad luck-the sandhogs won’t have it.”

“Don’t get ahead of yourself, Coop,” Mike said.

“The blood in the tunnel,” Mattie said, pushing several pieces of paper toward me. “You can see for yourself what I mean. This profile was sitting on my desk last night, right next to my folder on the Hassett case.”

She slid two pieces of paper together-one from Bex Hassett’s file and the other from the water tunnel evidence-and pointed to the alleles that aligned with each other at thirteen loci within the cell to create a distinctive genetic profile.

“You want to talk anomaly, Coop? The DNA in that blood sample from evidence in Water Tunnel Number Three-it’s a perfect match to the DNA of Trish Quillian.”