The Third Twin - Ken Follett [34]
“It uses fuzzy logic to speed up pattern matching. The pairs we’re looking for are similar, but not absolutely identical. For example, x-rays of identical teeth, taken by different technicians on different machinery, are not exactly the same. But the human eye can see that they’re the same, and when the x-rays are scanned and digitized and stored electronically, a computer equipped with fuzzy logic can recognize them as a pair.”
“I imagine you’d need a computer the size of the Empire State Building.”
“I figured out a way to shorten the process of pattern matching by looking at a small portion of the digitized image. Think about it: to recognize a friend, you don’t need to scan his whole body—just his face. Automobile enthusiasts can identify most common cars from a photograph of one headlight. My sister can name any Madonna track after listening to about ten seconds of it.”
“That’s open to error.”
She shrugged. “By not scanning the entire image, you risk overlooking some matches. I figured out that you can radically shorten the search process with only a small margin of error. It’s a question of statistics and probabilities.”
All psychologists studied statistics, of course. “But how can the same program scan x-rays and electrocardiograms and fingerprints?”
“It recognizes electronic patterns. It doesn’t care what they represent.”
“And your program works?”
“It seems to. I got permission to try it out on a database of dental records held by a large medical insurance company. It produced several hundred pairs. But of course I’m only interested in twins who have been raised apart.”
“How do you pick them out?”
“I eliminated all the pairs with the same surname, and all the married women, since most of them have taken the husband’s name. The remainder are twins with no apparent reason for having different surnames.”
Ingenious, Berrington thought. He was torn between admiration of Jeannie and fear of what she could find out. “How many were left?”
“Three pairs—kind of a disappointment. I was hoping for more. In one case, one of the twins had changed his surname for religious reasons: he had become a Muslim and taken an Arab name. Another pair had disappeared without a trace. Fortunately, the third pair are just what I was looking for: Steven Logan is a law-abiding citizen and Dennis Pinker is a murderer.”
Berrington knew that. Late one evening, Dennis Pinker had cut the electric power to a movie theater in the middle of a Friday the 13th movie. In the ensuing panic he had molested several women. One girl had apparently tried to fight him off, and he had killed her.
So Jeannie had found Dennis. Christ, he thought, she’s dangerous. She could ruin everything: the takeover, Jim’s political career, Genetico, even Berrington’s academic reputation. Fear made him angry: how could everything he had ever worked for be threatened by his own protégée? But there was no way he could have known what would happen.
Her being here at Jones Falls was lucky, in that he had early warning of what she was up to. However, he saw no way out. If only her files could be destroyed in a fire, or she could be killed in a car wreck. But that was fantasy.
Might it be possible to undermine her faith in her software? “Did Steven Logan know he was adopted?” he said with hidden malice.
“No.” Jeannie’s brow wrinkled in a troubled frown. “We know that families often lie about adoption, but he thinks his mother would have told him the truth. But there may be another explanation. Suppose they were unable to adopt through the normal channels, for some reason, and they bought a baby. They might lie about that.”
“Or your system could be flawed,” Berrington suggested. “Just because two boys have identical teeth doesn’t guarantee they’re twins.”
“I don’t think my system is flawed,” Jeannie said briskly. “But I am worried about telling dozens of people that they might be adopted. I’m not even sure I have the right to invade their lives in that way. I’ve only just realized the magnitude of the problem.”
He looked at his watch. “I’m running out of time, but