Criminal Psychology

Dynasty moves very fast.

When Zheng Xiaoming's parents walked out of the portrait room with their son dizzy, the little fat man was snatched away by a scary young man running in front of him.

Lin Chen pressed Zheng Xiaoming's parents, and said gently: "They may have some problems, and they need...to communicate in private..."

Xiao Ming's parents were so dazed that Lin Chen had no choice but to invite the two parents to the lounge and make two cups of tea.

Through the glass window, Wang Chao could be seen face to face with classmate Xiao Ming, having a chicken-to-duck conversation. Wang Chao kept talking, but Zheng Xiaoming looked up blankly, as if I couldn't understand what you were talking about.

Seeing the two of them like this, the surrounding police officers surrounded them curiously.

"Little Dynasty, are you speaking Chinese? Why can't I understand a single word?" A police officer next to him joked, "My kid will faint if you ask me."

Wang Chao glared at the other party and waved his hand: "You mortals don't disturb our communication!"

A moment later, a very bizarre scene happened. Comrade Zheng Xiaoming opened the dynasty, sat on Comrade Xiao Wang's office chair stuffed with cushions, faced Comrade Xiao Wang's computer without any embarrassment, and typed a few Chinese characters in a decent manner. Afterwards, a large number of pictures of high-rise buildings appeared. Zheng Xiaoming looked at one of the buildings, took a piece of paper, wrote down a series of values, and then jumped off the chair very well, put his hands on his stomach, and looked up at Dynasty again.

"Are you sure?" Dynasty asked.

Xiao Ming nodded.

All the police officers around surrounded him, but no one dared to speak.

Wang Chao groaned, quickly jumped into the chair and began to operate the computer.

Lin Chen nodded to the two adults in the lounge and walked behind the crowd.

Several police officers stepped aside, Lin Chen stood behind Wang Dynasty's office chair, and the little fat man quickly rubbed against his legs.

Lin Chen had never understood Dynasty's computer interface before. The young man typed a large piece of code, and then turned around to see a large group of people surrounding him. He said in horror, "Why are you all surrounding me? I'm so scary!" !"

"I heard that the murderer tied the murder weapon to a balloon and let it go?" asked a police officer.

"I heard that you are going to retrieve the murder weapon?" Another police officer asked.

"We're going to watch you pretend," said a third person.

Wang Chao said "Damn", and was scalped by Xing Conglian: "Speak well, how are you going to find it?"

"The most primitive search method is to drag the net across the city. We release the news, determine the last location of the balloon based on the report information of the witnesses, and then judge according to the wind direction of the day. Cutting vegetables can always be picked up by the masses or searched by us, it's just a matter of time, right!"

"Nonsense." Xing Conglian was annoyed.

"I have a faster method. I can calculate the approximate location of the murder weapon and narrow it down to the size of five football fields. If all goes well, we can find the murder weapon before dark today and call it a day!"

"Explain." Xing Conglian said.

"It's like this. There is a mathematical model in meteorology that specifically looks for the landing point of the weather balloon basket after it is cut. We can use this model to determine the possible landing range of the murder weapon after the balloon released by the murderer exploded at high altitude."

"But how do you determine where the balloon exploded? There are too many possibilities, and it even has a lot to do with the gas in the balloon, the weight of the knife, and the material of the balloon skin." Xing Conglian paused and asked; " Shall we do an experiment?"

"Boss, this is also a primitive search method, but of course the experiment must be done." Wang Chao smiled, "Xiao Ming's mother said that the balloons given to Xiao Ming by the murderer are the ones sold in the paradise, so we will buy some later , tie a heavy object underneath and let it fly, so as to find the last possible landing point of the murder weapon." The young man said, and handed over the value written by Xiaopang just now.

"What the hell is this?"

"Oh, my brother just calculated the weight under the balloon, which is the possible weight range of the knife."

Lin Chen looked at the value on the paper: "How did you calculate this?"

"Physics in high school, estimating, I just taught my brother the get out of class, and he understands it, it's amazing!"

Lin Chen frowned, and looked at Wang Chao suspiciously: "Huh?"

Chao Dynasty was looked at very embarrassed: "Um... I just tried to see if he could understand. In fact, there are not many knives that can be lifted up by three balloons, let alone stab people to death. They must be light in weight and Sharp, I just asked the forensics department, and they have determined the model of the knife. I just asked my brother to calculate it according to the method of physics, for a reference. In fact, at high altitudes, these weight errors can be ignored. "

"It's just pure showmanship?" Lin Chen looked at the little fat man next to Wang Chao's legs, very speechless.

Xing Conglian took the paper from Wang Chao, ignoring my brother who was open-mouthed by the young man, waved his hand, and called the police to arrange an experiment by the lakeside of Paradise.

The number of people surrounding Dynasty Computer, Ulala, has decreased by a third.

Wang Chao yelled at the back of the departing policeman: "Remember to install a GPS on it!"

Xing Conglian put his head back in front of the computer, and continued: "There can be experiments, but the wind speed will change every day. How can you finish it all at once?"

"Boss, here's another search method I'm going to talk about." Wang Chao said, feeling a little excited, "Boss, you just said that the difficulty of calculating the final landing point lies in the time when the balloon explodes at high altitude, right? There are many situations where two balloons explode and one doesn’t burst, so the trajectory will be very erratic, so how can we calculate the erratic trajectory of the balloon?”

Comrade Xiao Wang dragged his tune, and no one paid any attention to him, so he had no choice but to increase his volume, asking and answering himself vigorously: "Radar."

"It's impossible." Xing Conglian said, "How can it be possible to detect such a small balloon and its attachments? The weather balloon can be detected by radar because its volume is 10-20 times the size of a normal balloon."

"Have you heard of the airport bird detection radar?" Wang Chao asked.

"Continue." Xing Conglian stopped talking.

"The radars are all the same. I don't know the specific principles. Commonly used moving target radars can detect normal high-speed moving targets, and at the same time suppress fixed useless targets such as buildings, mountains, and clouds. But for small reflection cross-sections and low-speed moving objects Objects cannot be identified, in order to detect such low-speed flying things with small reflection cross-sections through radar, it is necessary to improve the filtering algorithm, and this algorithm is probably worth more than a billion."

Xing Conglian glanced at him: "Let your brother Ah Chen stand here and listen to you talking nonsense for 10 minutes, so there is no condition to talk about."

Wang Chao was immediately deflated, and could only say, "Let's go to the Aviation Administration and ask for a copy of the radar data after yesterday's incident. I'll filter it, but the algorithm is not for sale!"

The time when the murder weapon was found was not too far from what Wang Dynasty had estimated. The police could always find something they wanted to find without accident.

Before that, Lin Chen had been sitting in the lounge without saying much, and refused Xing Conglian's arrangement to send him to the hospital. He took off his shoes and sat cross-legged on the sofa, watching everyone in the police station get busy.

Zheng Xiaoming was sitting next to him doing his homework. The little fat man's parents still had to go to work in the afternoon, but because the child really refused to go back to school to continue classes, they could only leave him at the police station.

Lin Chen watched the child hold the pencil with his fleshy fist and try hard to copy Chinese characters stroke by stroke in the notebook.In fact, creatures like geniuses are not scary. The scary thing is that geniuses themselves have strong willpower, which can basically destroy the earth.

When Xing Conglian took the time to come in, Lin Chen was stroking the child's head, teaching him to study hard at school.

"I thought you would suggest that his parents send the child to the genius class to be with his kind." Xing Conglian took a glass of warm water and put it in his hand.

"Is there such a primary school in Hongjing?" Lin Chen asked. "

"Eh..." Xing Conglian squeezed to his side with a smile, "How about we open one?"

Lin Chen held the water glass and smiled.

"Your smile is far-fetched, Consultant Lin." Xing Conglian said, "It's not like the kind of smile that makes you feel sweet when you see me."

Lin Chen didn't accept the joke.

"Since you knew the suspect had let go of the murder weapon, you have said very little." Xing Conglian finally said.

"No, I just find it hard to explain clearly." Lin Chen took a sip of water, "I still think it's unnecessary."

"Ok?"

"It's a balloon and a flying weapon. The target is too big. Would a shrewd killer do this?"

"It's hard to say. It depends on the killer's personality. He's born with some perverts. He's very excited after killing someone, and wants to do a striptease." Xing Conglian said.

"Yeah, so I also think it's hard to explain this matter clearly." Lin Chen shook his head, "If he is a professional killer, it should be impossible not to know that the police will find his lethal weapon. In order to get rid of the murder weapon as soon as possible, I can understand. But why he didn’t tie the last balloon to the murder weapon, but took it away and gave it to Xiao Ming at the end, I really can’t understand such a state of mind.”

"There is a saying that the murderer should quickly release the evidence related to the murder in batches, but it is not so reasonable to explain why he gave the balloon to Xiao Ming here."

Lin Chen really didn't know what to say. In the end, he could only say to Xing Conglian: "I think it must be that I have nothing to do with this murder case, so I have to find some meaning for myself."

"Xing Conglian said seriously: It's all because Wang Chao is too capable. I'll go back and beat him up."

Hearing this, Zheng Xiaoming, who had been doing his homework, raised his head, looked at Xing Conglian with frightened eyes, and moved his butt to the other side of the stool by the way.

This action was so cute, Xing Conglian walked over, held the child's face and kissed it.

Zheng Xiaoming and Wang Chao are probably similar in some respects. After being kissed by Xing Conglian, he stood up without saying a word, walked to the tissue box, took out a tissue box, folded it, and began to carefully wipe the side of his face. He was punished from the place where Lianqian had been.

Xing Conglian was dumbfounded.

At this moment, excited celebratory sounds suddenly erupted outside the lounge.

Lin Chen shuddered, and exchanged a glance with Xing Conglian.

A police officer rushed in and shouted, "Boss, we found that black bag!"

"So fast?" Xing Conglian stood up, very surprised.

"It happened to fall on a lawn in the suburbs, and it was very conspicuous. Xiao Wang calculated the address, contacted the police over there, used a metal detector, and found it in no time."

About 10 minutes later, the black plastic bag and the murder weapon wrapped in it were sent to the Hongjing Criminal Police Team, with ropes wrapped around it and the remains of the balloon burst.

Because the process of finding the knife was so exciting, when the physical evidence was delivered, most of the forensics department and forensic doctors surrounded it.

The black plastic bag was carefully torn apart layer by layer, finally revealing the silver-white, bloody blade inside.

Everyone present felt a strange sense of relief.

Xing Conglian backed away from the stage and said, "Let's start working, first confirm that this knife is the murder weapon used by the criminal suspect."

The blood sample stained on the blade was extracted, and the police officers of the forensic department began to examine the plastic bag and the scotch tape wrapped around the plastic bag for fingerprints.

When the test results came out, Lin Chen and Xing Conglian were eating in the cafeteria with Wang Chao Zheng Xiaoming.

Zheng Xiaoming prefers the braised chicken legs cooked by the chef in the canteen of the police station. In order to show the good virtues of brotherhood and brotherhood, Wang Chao made an exception and bought five chicken legs with 30 yuan from his small coffers, and gave them all to Zheng Xiaoming. .

Lin Chen looked at Zheng Xiaoming who had already eaten three whole chicken legs and was about to eat the fourth, and felt that this was not good, so he silently moved the vegetable bowl to a place where Xiao Ming could not catch it, that is, in front of Xing Conglian.

Xing glanced at the linked fingerprint report, and asked with some surprise: "The fingerprints on the tape and the fingerprints on the notebook I brought back from Stancom's office are definitely from the same person?"

"Yes." The policeman nodded, and handed the second piece of paper to Xing Conglian: "Then we analyzed the blood sample on the knife and confirmed that it belonged to the victim Stankham."

Xing Conglian nodded, sighed, and raised his chopsticks to put the chicken legs into his bowl.

Suddenly, the police officer continued: "At the same time, another set of DNA samples that did not belong to the victim Stankham was found on the murder weapon, and a match with the second set of DNA samples was found in the library."

Lin Chen raised his head suddenly, and Xing Conglian's chopsticks stopped in midair.

"Who is it?"

The policeman handed over the last piece of paper in his hand and said, "It's called Duan Wanshan."