The tape measure formed a right angle to the ground in Christina's hands, and Christina was bent over and adjusting the distance between the tape measure and the weekend. The moment when the equilibrium distance was appropriate, it was the moment when the experiment began.

On the weekend, he was a criminal policeman with solid assertion skills. This is normal in China. He has also seen an old traffic policeman who can tell whether there is anything wrong with the car by his ears, and he can identify the authenticity of the license plate with his eyes at night. Some people can even judge height, weight, age, O-shaped legs or X-shaped legs by footprints. These mysterious things that sound like they are all things he has seen with his own eyes.

As for these talents, they are born with natural eyesight, just like a person's normal vision is 1.2. Some people are born with a clairvoyance of 6.0.

On the weekend, he sat on the toilet and opened the lid of the Coke cup and used a straw to bring a drop out of the Coke. This was not accurate, so he buckled one end of the straw in parallel with his thumb, and let the Coke fall naturally from the straw with his hands hanging naturally. When everything happened, the white paper that had long been spread on the ground told him a wrong answer, that is, the moment the Coke landed, there was a splash, rather than a round drop.

"How tall?" said Christina, turning his head over to ask over the weekend.

Christina, who had learned the steps before the experiment, has been paying attention to distance. She used her thumb and index finger tip to jamm the numbers on the tape measure, and after putting it away, she responded: "About 17 cm."

“A little more precise.”

“16.8 cm.”

I picked up the straw again on the weekend. After dipping the capacity in the cola that was about the same as before, I moved my hand slightly down and watched the Coke gather at a distance of 15 cm and slowly drip on the edge of the straw.

Next, he moved downward at a distance of two centimeters each time on the weekend, until a row of coke dot marks of different sizes appeared on the white paper.

This is the forensics method of the forensic department. When facing a drop of blood that does not know its capacity, countless experiments will be used to judge the distance of the drop of blood falling from a high altitude. The diameter of the drop of blood can be determined only when the diameter difference is extremely small or even the same, otherwise it will be necessary to start over without any doubts.

After the first round of tests, the diameter of the cola dripping marks on the paper and the diameter of the blood dripping marks next to the toilet were measured on the weekend. The most similar one was the position of 14.3 cm, but the diameter still had errors in the data, which means that the capacity of the cola he used to touch the straw was wrong.

The same experiment was unfolded again. In this experiment, the measurement of cola was reduced in this experiment, and the distance was also reduced to between 13 cm and 18 cm. Finally, at the position of 13.5 cm, the dots with approximately the same diameter were obtained on the weekend.

“BINGO.”

On the weekend, when there was a little excitement, I compared the white paper with many traces with the blood drops behind the toilet. After measuring three times in a row, I dripped three drops of Coke at the same distance again, and then I confirmed the answer.

"What can this tell us?" Christina heard the weirdness of this drop of blood on the weekend before the experiment, and she also sat on the toilet in person. The experiment proved that even if she accidentally injured somewhere on her arm, it would be impossible to drip into such a difficult position if the blood drips to the fingertips. So, she believed that the weekend was not doing useless work, but she wanted to know what she could get after doing so much.

"It can tell us that a person has dripped this drop of blood in what position he has dripped, and the person is in a state of numbness or unconsciousness. It is very difficult to fix such a person on the toilet. You have to make his head rest in which position he is stuck, otherwise it is very likely that a sliding of his head will cause the person to fall next to the toilet. Judging from this drop of blood, this person has at least been sitting on the toilet for the time that the blood can gather into drips. During this period, his head must be placed in a position."

Christina seemed to understand something: "No matter where his head rests, the grease on his hair will stick to it. If there is a purple light, you can find it immediately."

"With the position where he leans on his head and the distance where blood drips, the forensic personnel can calculate the length of the arm based on the approximate human body proportions, and the arm span can tell us the approximate height of the person."

"If this person is just drunk and excited, the gangsters outside will definitely not care. Assuming it is not..."

Christina asked again: "This is not enough to settle the situation we are now?"

"If there are purple lights, it's almost the same." The weekend was not fully guaranteed.

"I have."

"How come you have those things? I remember that the purple light and ballistic laser should be standard for the forensic department, right?"

"When the forensic department changed its equipment two days ago, Ronnie gave it to me, saying it was a toy for the child..."

...

In the living room, Heisenberg and Joey looked at each other. They had not spoken for a long time. Since entering the toilet with Christina on the weekend, they both hoped that the two of them could discover something.

"Hey, COP, when are you going to lock us up? Wait until that Asian and black people have children?"

Joey pointed at the black man lying on the ground with a rifle and said, "YOU-SHUT-UP!"

The black man glanced at him and looked away angrily.

At this moment, footsteps came and he walked out quickly in police uniforms over the weekend. This time, he showed unprecedented anger since he came to the United States.

bump!

On the weekend when he rushed into the living room, he grabbed the neck of the black man who had always liked to be stubborn with the police, and shouted loudly: "Do you want to write a suicide note? This time you are finished!"

After saying that, he pulled the black man's neck on the weekend and pulled him up from the ground, and pulled him into the toilet. When the black man entered the toilet, he kicked him in the black man's legs and knelt on the ground, pressing the black man's head and laying on the ground, pointing at the blood drop and saying, "What is this?"

"How do I know?" The black man took a look first, then answered quickly after he was silent for about a second.

"You don't know?" Christina took a chance: "You don't know there is a drop of blood in the toilet in your house?"

"SO-WHAT?" The black man was still struggling.

I found the paper on the weekend and spread it flat in front of this guy: "We just conducted an experiment and confirmed that it was a drop of blood dripping vertically, like this." I pointed out the most similar drop in the experiment to him on the weekend: "You who are watching the venue in the prostitute--you must have never heard of blood stain identification. Then I will tell you briefly that we came to the conclusion that it is very difficult to drip such a drop of blood vertically to such a hidden position. Only when the body is uncontrolled and ignores the pain of the toilet lid and water tank stuck in the back, it is possible."

Christina continued, "Here." She pointed to the toilet tank and slightly upwards: "There are traces of hair leaning against here, and the oil stains can be clearly seen under the purple light. However, your toilet was cleaned very clean, but the trace that cannot be seen by the naked eye is still there. Should you explain something?"

Bang.

She turned on the purple light that was always holding in her hand like a key chain. Under the light, there was indeed a ball of oil-like objects reflecting.

Their interrogation was just to avoid giving black people time to think. This is the most common interrogation method. Under such a fast pace of forcedness, a lie would definitely have loopholes when answering questions.

"Now, we suspect someone has been hurt in your toilet and has even died!"

"Hey!" The black man questioned with a strong sigh: "Why is he dead? Can't someone accidentally drip blood when he was injured?"

He asked without leaving any gaps on the weekend: "Who, you have to give us a name? Didn't you say someone was injured? After verification, it was confirmed that this person was still alive and you are all fine. The Complaints Department of the Police Department and the Ministry of Internal Affairs of the Mid-American Ministry of Internal Affairs welcome you to complain about the four policemen who broke into illegally."

The black man was silent, he wanted to think.

"SAY-some-thing!" Christina would never give him time to think and asked forcedly.

"Maybe some prostitutes - guests and prostitutes - had an argument. How do I know who was injured? There are more people here every day than those from the Immigration Bureau."

flaw!

He let go of his hand over the weekend, transforming the person's tightness that was restrained into normal state, and then squatted beside him and said, "So, do you admit that this is a prostitute--the-yard?"

“NO!!!”

"You can't prove anything with a drop of blood!"

The black man finally found out like a trap, letting out a huge roar, showing the desire to break free from it from his attitude.

"Are you sure?" counterattacked over the weekend: "Now I tell you my answer. The height of the human body is roughly equal to the arm span. Except for professional basketball players, the errors of others are very small. The most similar one of the cola liquid on this piece of paper is to determine that the blood drop is dripping at 14.3 cm. From the position of the head to the position of 14.3 cm from the ground, it is enough for me to infer the length of the arm, and the arm span can tell everyone that the height of the person is about 170 cm, with an error of 5 cm up and down!"

After giving black people a brief relaxation over the weekend, Christina said at this time: "Relax, friend." She squatted down and said as kindly as possible: "You should have heard some news that the son of the police chief Derek is dead. Now the police in the town are looking for the murderer, so..."

After taking over the conversation, he continued: "So, our main target is not you, nor this house or this brothel." He looked at the black man who had climbed up from his lying position and changed to sitting on the ground on the weekend and said: "I give you two choices. First, tell me the name of the injured person; second, tell me if you heard gunshots yesterday, or know which gun dealers have sold guns to very suspicious guys recently."

“I have the right to refuse.”

"Of course, this is the United States, but after you refuse, we will apply for a lie detection procedure. At that time, you have to face the confession just now for a lie detection."

"I ask to see my lawyer!" The blacks kept looking around while talking. This was a signal of distress in criminal psychology. The interrogation room of the US police station was designed based on this. They would squeeze the prisoners in a dead corner with their tables, and two policemen sat opposite the tables and at the exit where the prisoners could walk around the tables. In this way, no matter where the prisoners looked, they would quickly fall into despair during the interrogation.

Lie detection is a very useless thing in the United States. Since this thing was developed and put into use, courts have rarely used lie detection results as evidence. However, lie detection has become an important judgment during police interrogation. Like gunpowder testing, if you do not shoot and kill someone, you will not be afraid of gunpowder testing. Of course, there is no need to be afraid of lie detection without lying.

On the weekend, he suddenly looked at Christina, and the two of them were delighted. The pressure formed by using the death of Derek's son and a drop of blood that was incompatible made the black gangster very suspicious. He neither wanted to give a name nor participated in a lie test. He even asked about the death of this toilet on the weekend that he did not deny it, "You are talking nonsense, accusing," but instead used it as perfunctory "maybe someone was injured."
Chapter completed!