When Li Nan saw Li Bin for the first time, he hated him.

This ugly monkey wrapped in a futon with a wrinkled face is a sinner who causes his mother to be weak and exhausted. She lowered her head to look at the monkey in the cradle, and for the 10,000th time she didn't want to believe that it was her brother.

"When your mother gave birth to a younger brother, she threw you away?" When I got home, I heard the voices of my relatives ring again.

Xiao Li Nan grimaced fiercely and ran away.

For this second child, Li Nan felt that her mother was reluctant. And the reason for giving birth to Li Bin is also very simple, Li Nan is a girl.

Judging from the name her grandfather chose for her, what the Li family really wanted was a boy.

However, what everyone didn't expect was that Zhou Zhou Liu disappeared more than a month after giving birth to the child and has not been heard from since.

Li Nan felt that her mother might have been angry with Li Bin.

This monkey either eats, sleeps, or pulls all day long. And my mother is very good to herself, and often sticks to her little face and says, "You are my little lucky star." ”

After her mother disappeared, Li Nan tried to find her for a while. The father was sad outside, but when he returned home, he didn't look anxious.

In any case, he already has a son anyway.

But for Li Nan, life has plummeted.

In the past, before she went to school, her mother would tie her braids, change into the most beautiful dress, and apply a layer of fragrant cream for her, and all the children wanted to be friends with her when she walked on the road.

Li Jianjun is a different kind of painter, he wants boys, but it is not good for Li Bin - in fact, he will not raise children at all.

Li Jianjun's mother came occasionally a few years ago, but soon patted her chest and said, "Oh, this is a little Hades, crying to me like this will kill me sooner or later."

So I never came again.

Li Bin loves to cry, he can be called crying from morning to night, and after crying hoarsely, he makes an ugly tearing sound, and after losing his strength, he looks like a faint panting ghost.

After a few months, he finally stopped crying. After Li Jianjun's death, Li Nan himself was only seventeen years old at the time, so he sent him to a boarding school.

said that they are sisters and brothers, the two are more separated than strangers, and they are blood relatives who hate each other but cannot be separated.

In this case, how can he be polygraphed?

Li Nan took a deep breath and avoided Xu Youchu's eyes.

"The victim is only 12 years old, a little girl is lying on the scrap pile, do you want me to take you to see it?"

Li Nan flicked his curly hair and said without emotion: "Our unit has not received many commissions for criminal cases, and this situation is a bit special, you have to contact my leader." If the process is fine, I can do a polygraph. ”

"We'll get in touch right away, and then set up the venue," Xu Youchu breathed a sigh of relief, "Does a hidden camera affect your work?" ”

"No, it won't."

In an instant, the office was temporarily converted into a psychology laboratory, and Li Nan observed Li Bin, who had been sitting on a stool for hours—she was looking at him from the perspective of her subject.

As a polygrapher, she always needs to be objective and neutral, and not let past experiences and biases affect test results.

The latter looked extremely tired, was this the result of a night of travel?

Li Nan hurriedly conceived the logical framework of this polygraph, and when she did this kind of thing, she seemed very excited, and she rarely had some human flavor. Specifically, she walked out of the door and grabbed a small policeman: "I have to let him eat something and rest for a while, otherwise it will affect the data." ”

"Okay, okay." The policeman stammered back.

At four o'clock in the afternoon, everything was ready.

"What are you going to do?" Li Bin also saw her work for the first time, and when he saw the strange-looking lie detector chair, he asked vigilantly.

"Take a polygraph on you."

Contrary to what most people think, polygraphs are not a pretentious profession. In the early years, many polygraphers believed that the person being tested should not be told the principle of the polygraph, because it was more troublesome to explain, and because the information asymmetry could be used to have a strong psychological deterrent to the person being tested, so that he would not dare to lie.

For example, tell the subject: "This instrument is very powerful, as long as you lie, you will know." So you have to answer truthfully. ”

Nowadays, a large number of laboratory empirical studies have proved that when the test person understands the basic working principle of the polygraph, the accuracy of the conclusions obtained by the former polygraph is significantly higher than that of the latter compared with the person who does not know the working principle of the polygraph.

There are two points involved:

1. Can a lie detector lie during a lie test?

If from the beginning, all of this was just a different lie, then the search for truth would have been a mirror.

Li Nan has an aversion to making the polygraph principle "mysterious", which would make her look like a god rather than a scientist.

Second, how does an innocent person feel when he does not know the principle?

One of the hardest aspects of polygraph detection is that it is not only the perpetrator who has psychological fluctuations, but also the innocent.

How do you distinguish between the tension of crime and the tension of polygraph itself?

The little heads of those innocents are full of so many cranky thoughts:

- Do they suspect that I did it? What to do?! I'm a suspect! If this machine is mistaken, I'll be wronged......

Simply telling the truth about the principle before the test can relax the honest and make the liar more nervous.

Authenticity has its own power.

"I'll tell you what I'm doing now, in fact, polygraph is a mature psychological application technology......" Li Nan calmly told him a series of informs and explanations.

Li Bin lay stiffly on the lie detector chair as if he had met his sister for the first time, his eyes widened.

Before the polygraph is officially started, there will be a conversation with the purpose of recording the data of the person being tested in a normal state.

Li Nan: "What's your name?" ”

Li Bin: "? ”

Li Nanpi said with a smile: "Just kidding." ”

Behind the camera, Xu Youchu and his entourage looked at the pair of sisters and brothers solemnly.

"What do you like to do at school?"

"Daze, fight, sleep," Li Bin glanced at her defiantly, he was ready to receive cold words from Li Nan.

This time, the latter just said "oh" and even added, "I was always in a daze when I was in school." ”

"But you're doing well." There are many awards on the wall of the house that Li Nan took back.

"I've inherited my mother's intelligence."

No one would have thought that the first peaceful chat between the two siblings would be in this situation.

In the subsequent formal polygraph, Li Bin opened his mouth to talk about last night's incident:

"After class at six o'clock last night, I went to the cafeteria to eat, and at that time I met Liu Wenxuan, who looked panicked...... Well, I asked her what was going on, and she said she had a fight with her family, was in a bad mood, and didn't want to go home. ”

"She told me she was running away from home, and I thought she was joking. Then at half past seven, I started evening self-study, and I was sleeping. Then I woke up and felt bored, so I thought about going to the Internet café at night to surf the Internet. Well...... Around 8:50, I skipped class and was about to sneak out. Because it is generally more strict when it comes to evening self-study, it is better to slip away in advance. ”

"It's past nine o'clock...... Well, I'll go out. But when I went out, I found that I didn't have much money on me, and I didn't have much to live on every month. I didn't want to go back to school, so I just wandered around the school. Well. Alone. Then I felt tired after two or three o'clock, so I went back to school, and I didn't see Liu Wenxuan halfway. I don't know. ”

Data anomalies. Data anomalies. Data anomalies.

If you look at the expression, you will feel that Li Bin's words are very sincere, and his eyes do not dodge in the slightest.

"Where are you at nine-fifteen?"

"Well," Li Bin said, "I'll ...... after class ends at six o'clock," he repeated.

"Well, can you tell me more about what happened before you went back to school in the evening, and reminisce from back to front?"

Now Li Bin was even more struggling, and he closed his mouth halfway through self-deprecation, and folded his arms in front of his chest.

Stereotyped narratives, often fabricated memories. Li Nan also looked at him deeply: "If mom is still here, I won't want you to be a child of lies." ”

"Haha, haha," Li Bin let out a piercing laugh when he heard this, "I'm sorry, I haven't seen her, maybe she's already dead." ”

"Please tell us the truth."

Li Bin came back from the wild laughter and looked even more gloomy: "The truth? What is the truth? Don't you just want to hear from my mouth that I did it? Want to hear me say that I followed Liu Wenxuan and then poisoned her? As I said, even if I do it, I'm not of legal criminal age. Instead of asking me here, let's ask Liu Wenxuan—"

"What did you say?"

"Huh? Are you deaf? I'll let you say that—"

Li Nan said: "You asked me to ask Liu Wenxuan?" ”

"yes, use your stuff to test her!"

Data anomalies.

Xu Youchu and Qiu Tian looked at each other behind the screen, because Li Bin had been locked up in this office in the morning, and his mobile phone had also been confiscated, and no one had informed Li Bin of the progress of any case.

Did he really not know? Or do you pretend you don't know? Is the anomaly in the data a weakness of mind or anger? Human feelings are so subtle.

There was a slight sound of electricity in the headset, Li Nan turned his head slightly to listen to the headset, and inside was Xu Youchu's voice: "Tell him that Liu Wenxuan is dead." ”

"Liu Wenxuan is dead, and her body was found this morning."

The data is significantly abnormal.

- Visible to the naked eye, Li Bin's face was pale, his pupils were dilated, and he stood still for a long time.

He really didn't know that Liu Wenxuan was dead.

"She's dead?! How can it be?! ”

"So what do you think is wrong with her?"

Li Bin hugged his head, and he said stunned: "I thought she was beaten...... Or they were raped. She's dead...... How so? How so? ”

"Yes. So I want you to tell you what happened last night so that the Crime Squad can bring the killer to justice as soon as possible. ”

"I don't know...... I don't know......" Li Bin curled up as much as he could, "impossible...... It's a dream, it's a dream. It's good to wake up, it's a dream, a strange dream. ”

Data fluctuations are extremely unusual.

Then, the data fell back to the average quickly, only about a minute later, and Li Bin returned to normal, as if he had become accustomed to this level of pain. "I know who did it," he said. ”

***

In 1991, China's first polygraph passed the expert appraisal organized by the Ministry of Public Security. According to polygraph data at home and abroad, the accuracy of polygraph is relatively high, and it can even reach 98% accuracy. However, because it is not 100% certain, there is still controversy in its use. At present, in China, some courts use polygraph technology as a reference in the trial of cases.