Please don't stick to Officer Qi [criminal investigation]

While waiting for the inspection, Qi Lin sat on the sofa in the living room and waited quietly while watching the documents given by Huang Yuanliang, while Shi Le was playing with his mobile phone.

"This house is so big, are you cleaning it alone?" Shi Le suddenly thought of something and asked the hostess.

"No, there is a professional housekeeping company that will clean it. A man came to clean it before. He has a very good service attitude. He even helped me support the board when I was doing the experiment."

Shi Le sighed, "Do experiments? Have you set up a laboratory at home? Big beakers, stills?"

The hostess was amused by Shi Le's innocent question, "There are many kinds of experiments. I just did some simple physics experiments."

"Ah, a physics experiment." Shi Le nodded, "It's amazing."

"It's nothing special. I used to be a physics teacher at Qingcheng University, and I did a lot of projects. After I got married, I stayed at home to prepare for pregnancy, so I did a lot less experiments." The hostess brought a tray with several cups inside. Two of them are instant coffee, and the other two are ice cubes, "Thank you for your hard work, let's drink some coffee."

"Thank you." Qi Lin was seeing the doubt, took the coffee and put it on the table.

Shi Le eagerly picked up the coffee and drank it, then stuck out her tongue, "It's so bitter."

"Should I switch to plain water? We don't have any beverages at home. The quality of this coffee may indeed not be very good..."

"No, thank you." Shi Le took a mouthful of ice cubes, which relieved the bitterness in his mouth, "It's not that coffee is bad, it's just that I'm not used to drinking it. Senior likes it very much, right, senior?"

Qi Lin didn't speak, but focused on the report.

The report briefly mentioned the alarm device, but did not elaborate.

The report stated that the prisoner used a cutter to cut open the kitchen window and successfully bypassed the alarm device. However, after the police experimented, it was found that this device was very advanced, and it would call the police no matter how disturbed it was.

Therefore, Huang Yuanliang was more inclined to the room where the prisoner slipped in through the door, and finally escaped with a cutter after turning off the alarm device from the kitchen.

The theory is feasible, but Qi Lin always feels that something is wrong.

"It is written in the document that the prisoner escaped from the kitchen, but I didn't find the kitchen on the first floor."

"The kitchen is on the second floor. I'll show you the way, and please follow me." The hostess spoke brightly.

There is a certain distance between the kitchen and the exhibition room, and you have to go back to the second floor after returning from the original path of the corridor.

There is a small balcony behind the kitchen, from which you can see the road in the villa area.

"It seems that I have been on the spot for a long time. This place is far away from the exhibition room. If I had a sudden intention, I probably would not choose to escape from here. The living room, garage, and even the small windows in the corridor are better than here." Shi Le stretched out his hand and pushed it away, and was drilled There was a big hole in the window, and sirens sounded from both sides of the window instantly.

Shi Le was taken aback, and the hostess turned off the alarm at the kitchen door.

"There's an alarm on this window?" Shi Le waved his hand on the window curiously. Every time he waved his hand, the alarm would sound briefly, and then the hostess would turn off the alarm with a dark face.

Children nowadays are too unreliable, and their hands are extremely idle.

Qi Lin really felt ashamed, and pressed Shi Le's hand that was about to move, "Did the alarm go off when the crime happened?"

"It's on, it's always on." The hostess went to the window to explain the principle to Qi Lin, "We installed the infrared alarm on the inside of the window, and it will alarm as long as there is an object blocking the infrared light."

Qi Lin looked sideways at the window frame, and there were indeed several small holes in it.

"But why not put it on the outside? Wouldn't it be faster to call the police by putting it on the outside?" The curious baby Shile continued to ask.

Qi Lin shook his head, "If you install it outside, it will trigger an alarm no matter if a bird passes by or a fallen leaf. The chance of false alarms is too high, so it is better to install it inside."

"Actually, it's not entirely true. The alarm device must cover more than three transmitters at the same time before it is judged to be a person's height and an alarm is issued. Birds do not affect it. As for the kitchen installed inside, it is because the window is outside the balcony. If there is a sun Clothes are likely to cover the alarm device and cause false alarms." The hostess pointed to a white line in the corner of the roof and said: "The white line on the top of the house is the alarm device connected to these windows."

Qi Lin followed the hostess' fingertips and looked towards the roof.This line goes straight along the roof and divides into many branches to every window.

According to Huang Yuanliang's report, the hostess was at home on the day of the crime and was doing yoga in the gymnasium on the first floor. No noise was heard during the theft, and no signs of forced entry were found at other entrances.

Why do you have to escape through this window instead of coming in through this window?If there are other ways to enter from the first floor, wouldn't it be unnecessary to escape from here?

There must be other ways to bypass the alarm.

"What is the working principle of this alarm?" Qi Lin asked the hostess, "If it is blocked with a piece of red glass, will it still call the police?"

The hostess folded her hands on her chest, "Yes, the alarm in this room is connected. If only one window is blocked, it will immediately alarm, unless all of them are blocked together, so the signal cannot be transmitted to the repeater. Only then can the alarm be blocked."

"Ah, really professional." Qi Lin praised: "Is this what the designer told you?"

"No, I'm a major in science and engineering. I researched this by myself." The hostess stroked her long hair, "I'm trying to get pregnant and don't go to work. I just think about it every day when I have nothing to do. But my thinking should be That's right, because I've tried it before."

"It really is a very advanced technology."

The hostess looked a little more happy to be praised, "I asked my high school classmate to help me design this. He is doing research on safety technology abroad, and he said it is a relatively high-end alarm system. And he built it on the original Improvements have also been added to the system, these windows can only block the transmitter, not the receiver. Once fully blocked, the alarm will also be reported.”

Do they all block the transmitter together?Qi Lin looked at it, and the kitchen was connected to the dining room next door, with a total of four windows.

However, if you can only cover the transmitting end, it is really difficult, unless you hold the edge of the board with your hands or fix it with tape, otherwise it will definitely affect the receiving end.

An inspiration flashed from the bottom of his heart.

He turned off the alarm and peered out one window after another.Outside each window is a smooth wall, and only one person can barely stand on it, and the exterior wall of the villa has no traces of adhesive tape.

If the alarm system can be bypassed without destroying the security system, then the only possibility is to block the transmitter with a red transparent plate, block the four windows at the same time, and then another person sneaks into the room from the kitchen window to turn off the alarm.

In other words, this gang is still a big gang, and at least four people are needed to sneak in.

Qi Lin counted silently in his heart, Gao Xiaolong, Zhang Xu, Zhao Yutang.

One more.

He felt that things were gradually becoming clearer.

More complex cases are often simpler.The reason why it feels complicated is that the clues are hidden too deeply.

"What time did you find out it was stolen that day?"

"At eight o'clock in the evening, after I finished exercising, I heard a sound in the collection room. I didn't pay attention to it at first, so I went to the dining room to drink water. Then I rested in the bedroom for a while, and the more I thought about it, the more something was wrong, so I thought about going downstairs to have a look, and found The jewel was gone. It was about 08:30. At that time I went to check the alarm very quickly and found that the alarm had been switched off."

"Where is the box containing the gems? Is it made of wood?" Qi Lin asked, holding his breath and waiting for the hostess' answer.

The hostess recalled for a moment, then nodded.

Qi Lin breathed a sigh of relief.

Case solved.

Before eight o'clock, four people held red transparent boards to block the alarm device of the window.Gao Xiaolong is the thinnest, so he should be responsible for the small window in the kitchen.He then entered the house, turned off the alarm, went down to the ground floor and stole the gem.

According to the original plan, the four of them should repeat the trick again, turn on the alarm device and escape, but because the hostess arrived at the restaurant during the period, the other three were forced to leave first in order not to be discovered, and finally Gao Xiaolong had to cancel the original plan. Plan, turn off the alarm and escape directly.

Even if the entire criminal process had flaws and unexpected circumstances, it was difficult to trace because no fingerprints were left on the scene.Had it not been for the death of Gao Xiaolong and the discovery of preservatives in his stomach, no one would have linked the two cases together.

Now the biggest mystery is the fourth person.

Who the hell is it?

Just then, Xiao Wang's phone call came in.

"Qi team, it's right, it's really the mark made by Gao Xiaolong's ring." Xiao Wang was pleasantly surprised on the phone, "Qi team, you are amazing, you can find such a small scratch."

"It's because you are not serious about what you do, and you haven't found such obvious traces." Qi Lin was not very happy, it was obviously very obvious, if Huang Yuanliang hadn't ignored this detail, then the case would have had a clue.

Three people will not die at all.

Three people died...

He suddenly thought of something, opened the photo album of his mobile phone, and stared at the photo given by Gao's mother before.

It was the graduation photo of Gao Xiaolong technical secondary school.

In the graduation photo, Gao Xiaolong was standing at the edge of the last row with a bright smile.The row in front of him with half of his head exposed was Zhang Xu, the second deceased, squinting his eyes because the sun was too glaring.

Zhao Yutang was standing in the front row, he seemed to be late, and he hadn't put down his tie arranging hand.

This graduation photo was taken in such a hurry, and it has been yellowing and curly with the passage of time, and then it was photographed on Gao's mother's mobile phone, and because the three people in it did some bad things, Qi Lin took it again go.

Now looking at this photo that was about to turn into black and white, Qi Lin felt that it was a bit appropriate.

Looking at it, Qi Lin saw a familiar face.

With a crew cut, he just closed his eyes and blinked in the photo. Even though the picture was blurry, Qi Lin still recognized him.

"What did Gao Xiaolong and the others learn?" Qi Lin asked Shi Le to confirm.

Shi Le thought for a moment, "Looks like an auto repair?"

Qi Lin fully recognized it now.

The employee who had met him once at the Zimashan scrapyard.

That's the fourth person.