Aria stayed silent as Madison took off a light jean jacket, draped it over a neighboring empty barstool, and sat down. Attentive as ever, Alex came over immediately to place a cocktail napkin in front of Madison. He repeated the introduction he’d given Aria, including extending his hand. In contrast to Aria, Madison shook the hand and gave her name in return. After a brief conversation, it was decided Madison was not hungry but would have a drink.
“I’ll have the same as she,” Madison said, nodding toward Aria’s glass.
“It’s prosecco,” Aria said, surprised someone would order something when she didn’t know what it was. She wondered if it meant Madison had already had enough to drink during the evening.
“Whatever,” Madison said. “I like prosecco well enough.”
“What is your suggestion about finding Kera Jacobsen’s secret lover?” Aria asked, eager to turn the conversation to business. It was at that moment when Alex brought Aria’s food. With it he provided chopsticks, a cloth napkin, several small dishes, and a small kettle-like container of teriyaki sauce. Although Madison said she wasn’t going to eat, he brought chopsticks and a napkin for her, too.
Aria tried a piece of the sushi and a piece of the sashimi, then pushed both dishes closer to Madison. “Not bad,” Aria said. “I’m starved. Try it! The sashimi is particularly good.”
Madison followed Aria’s lead. “Yum,” she said, then got down to business. “To explain what I have in mind, I have to ask you a question. Do you remember the arrest of the Golden State Killer in 2018?”
“I think so.”
“Do you remember how he was found?”
“As I recall, he was found by someone matching his DNA through one of the ancestry websites?”
“Exactly,” Madison said, becoming excited about the subject.
“Is this what you have in mind for finding Kera’s boyfriend?” Aria asked. She was immediately disappointed. She had expected at a minimum to get names of people who might have known Kera’s secrets.
“That’s exactly what I have in mind,” Madison said.
“Well, I can tell you right off, it’s not going to work,” Aria said, not trying to camouflage her disappointment. “Finding the Golden State Killer was a completely different set of circumstances. They had the man’s DNA from his semen. We don’t have our perpetrator’s semen or his DNA.” Aria put down her chopsticks. She was so disappointed that she was tempted to just leave.
“That’s true, but there is a good chance we can construct his DNA.”
“Oh, please,” Aria scoffed. “What the hell do you mean, construct his DNA?”
“About a year ago my mother gave me a present of having my DNA analyzed by one of the major DNA genealogical companies. At this point I can’t even remember which one it was. I think it was Ancestry dot com, which has the largest database. But it doesn’t matter because I’ve gotten into a genealogical obsession, and I’ve had just about all the commercial DNA companies analyze me. I tell you, once you start, it becomes addictive. And it works. I’ve found ancestors going back to the eighteen hundreds who were slaves.”
“I’m happy for you,” Aria said. She checked the time on her phone. It was nearing eleven, which explained why she was suddenly feeling like she wanted to be in bed. Normally she was in bed by ten or ten thirty to read.
“The point I’m trying to make is that I have become reasonably knowledgeable about the ins and outs of genealogical DNA. It’scomplicated stuff, but if you are persistent, like I am, you can figure most of it out.”
“I’m afraid I’m going to have to cut this short,” Aria said. She glanced down the bar and raised her hand with the idea of getting Alex’s attention.
“I think finding this boyfriend will be rather easy because we will have both the child’s DNA and the mother’s. That means we already have half the father’s DNA.”
Aria lowered her hand and looked back at Madison. “That might be correct,” Aria said. “But that still leaves one and a half billion base pairs that are unknown.”
“Yes, but there are some clever tricks to fill that in by using tools developed by the commercial DNA companies and aided by websites that are called open databases. Let me explain: When you send in your saliva sample to a company like Ancestry dot com, what you get back is called a kit. It is not your DNA completely sequenced, although maybe in the future it will be. But for now, it’s your particular collection of varying nucleotides at various precise locations spread through your entire genome. These precise locations are called SNPs, standing for single-nucleotide polymorphisms. It is sort of like a fingerprint in chemistry.”
“I understand all this,” Aria said with a bit more interest. Madison seemed to know what she was talking about. Aria had never thought about the idea of finding someone by figuring out what their DNA was from close relatives. She’d always thought that such a process was unidirectional, the way the Golden State Killer had been found, by having his DNA to start with.
“Of course, you know most of this stuff about DNA since you are a doctor,” Madison said. “I’m sure you know more about the nuts and bolts than I. At the same time, I can tell you’re not up on the latest about what genealogical DNA is capable of doing. These days there are some wild tricks that have been developed, particularly by companieslike GEDmatch dot com. One’s called phasing, which separates the child’s DNA into DNA obtained only from the mother and DNA only from the father into new kits. There is even a really cool one that involves making a manufactured kit for the ‘evil twin,’ meaning an artificial kit of the DNA the real child didn’t get from the parents.
“But that’s getting ahead of ourselves. All you have to understand at the moment is that these new manufactured ‘phased’ kits can also be used to find ancestral matches. In Kera’s case we will only be interested in matches from the paternal side, which is why the phased kits are helpful. And if paternal matches are found that are closer than third cousins, chances are we will be lucky, especially if these matches have made the effort to construct family trees. If we end up getting even closer matches, such as siblings, half-siblings, parents, or aunts or uncles, even first cousins, it would make finding him a piece of cake.”
“Really?” Aria said, her mind in a swirl. For several beats she stared at Madison. What she was hearing was opening up a whole new possibility that had not occurred to her, and she struggled to put it into context. “This means we’ll have to have kits made for both Kera and her child by any one of the commercial DNA companies.”
“Right on,” Madison said with building enthusiasm. “And the more companies we use, the greater the chances for matches to be found. I’m going to turn you into a convert, I’m sure of it.” She let out a little laugh of satisfaction at Aria’s response. “What I’ve learned studying all this stuff is that on average a person has about 850 relations who are third cousins or closer. Just to remind you, third cousins share great-great-grandparents. Now, don’t be discouraged by thinking we’ll have to be sorting through 850 people. No way. By guessing the mysterious boyfriend’s age, we can probably halve that number. Then by excluding female matches, we can halve it again. And finally, restricting the matches to the New York City area, we’ll be halving it again.”
“So, you think we’d end up with a hundred people or so?” Ariaquestioned with renewed discouragement. Trying to narrow down a group of a hundred people in a city like New York would be a monumental task even for a team of professional investigators.
“No, no,” Madison said. “Probably less than twenty. Restricting the matches by age narrows it more than fifty percent, a lot more. And if there’s a close match like a sibling, a parent, or an aunt and uncle, then we’d be looking at a lot less than five or six people. It might only be one person. Bingo! We got the bastard.” She smiled. “All this excites me because it will hopefully provide some redemptive value. I’ll feel like I’m doing something for Kera by finding this dude, even if it’s too late to save her.”
