The Trapped Girl (Tracy Crosswhite #4)(81)

A door in the corner of the room pulled open and a blond-haired man, partially balding, stepped out wearing a white lab coat over a pink dress shirt and red tie. “Detectives,” he said, giving them a 100-watt smile. “I’m Tim Lane.” They shook hands. “Come on back.”

Tracy and Kins followed Lane down a carpeted hallway. He led them into a nondescript conference room with a window that looked out over a small area of once-green lawn showing patches of brown. Lane stepped to the far side of the table, on which he’d set two manila folders.

“Mike says you’re to get the VIP treatment,” Lane said, his voice deep and rich.

“Heard you’ve been trying to recruit him. The detectives would revolt,” Tracy said.

“We worked at the crime lab together, many, many years ago,” Lane said. “I only lasted five years.”

“How’d you get into the private sector?” Tracy asked.

“I majored in chemistry and went back for my MBA. I’ve always been entrepreneurial and wanted to run my own business. With the advances in DNA and the backlog of cases at most major metropolitan crime labs, I saw an opportunity I thought I could fill. We were one of the first private labs. Now you Google ‘private DNA testing’ and you get a couple hundred thousand hits.”

“How much of your work is for the general public?” Kins asked.

“It’s about sixty percent now. When we first opened we were basically an annex for the crime labs. We did a lot of paternity testing. Over the years, with advances in DNA testing and technology to perform that analysis, the crime labs can get through their cases a lot faster than they could when I was there, and don’t have as much of a need for outside labs. Eventually, you won’t need us at all. You’ll get the bad guy’s DNA profile, put it up on a cloud, and it will run through all the major databases and spit out results in minutes.”

Lane sat. Tracy and Kins took two chairs across the table from him. “Mike also said you guys don’t need any hand-holding, so I’m going to get right to it, if that’s okay?”

“That’s fine,” Tracy said.

Lane opened the first folder. “We used the profile Mike sent us as our baseline for comparison with the two DNA profiles you provided. The first profile, we were asked to determine if the person could be the victim’s aunt.”

“Correct,” Tracy said.

“We can determine with a much higher degree of certainty whether two people are related,” Lane said, slipping into his comfort zone. Tracy and Kins had both received educations about DNA testing and analysis through their work on several trials, but Tracy let Lane continue. Her father had once taken her to buy her first six-shooter, and although he had been shooting six-shooters since he could walk, he had patiently listened as the seller went through every aspect of the gun, then thanked him for his thoroughness. When they left the store, Tracy asked her father why he had endured the lecture.

“Interrupting a man when he’s discussing his profession is like telling him what he has to say isn’t important. Besides, you never learn anything when you’re talking.”

Lane continued. “But without the DNA from at least one parent, we can’t be certain.”

“The parents are deceased,” Tracy said.

Kins said, “So what did you find in this instance?”

“In this instance we performed a statistical analysis based on the match type typically expected for a known aunt-niece relationship. This provides us with what’s called a ‘kinship index.’ A biologically related aunt and niece typically have a kinship index value greater than 1.0. Conversely, if they are not biologically related, the kinship index value is less than 1.0. The closer to or more distant the kinship index value is to 1.0, the more or less likely the two individuals are related.”

“And in this case?” Tracy said.

“In this case the kinship index value was significantly less than 1.”

Her adrenaline spiked but Tracy did her best to temper her reaction. “So they’re not related.”

Lane shook his head. “The statistical probability is they are not.”

“You said ‘statistical probability,’” Kins said. “What are we talking about here? What are the percentages?”

“Negligible. If you want percentages, I’d say it’s 99.95 percent they are not related.”

Kins glanced at Tracy but also didn’t say anything. She knew him well enough to know the wheels were spinning in his head too.

“And the test to determine siblings?” Tracy asked.

Lane closed the one manila file, slid it across the table to Tracy, and opened the second file. “Again, the recommended method to determine whether individuals are true biological siblings is to test their parents. DNA paternity and maternity testing will always provide conclusive results. That not being an option here, we are again left with probabilities. In this case, based on the type of genetic material inherited by each sibling, we determine what’s called a ‘sibship index.’”

“What did you find?” Tracy asked.

“The sibship index was well over 1. The statistical probability is that the two women in the genetic profiles you provided are full siblings.”



Tracy and Kins stepped outside the lab with Tracy holding the results of the two tests. Kins slid on sunglasses against the bright glare. “I’m not going to lie; a part of me was hoping we’d get the opposite result.”