Du Linfeng, Linsou, and the case investigation team have all returned to the dormitory to rest, and only the instructors are left, and they are already asleep on the table.

Where can Xu Zige sleep? He greeted Chen Zhen in his heart.

Finally, after Chen Zhen had almost finished drinking, he talked about the key mobile phone.

Chen Changjin used Nokia's straight-board mobile phone. He didn't know how to use it with his smartphone, so Chen Zhen taught him step by step how to check the address book and send text messages. He also took out his phone and taught him how to play Angry Birds.

Chen Zhen held a toothpick in his mouth and said with a smile: "There are many functions here, and it is different from the old-fashioned phone. The signal is much better. Take your phone over and I'll plug the card in for you."

"Oh, OK, OK."

Chen Changjin didn't know it was a plan, so he handed his Nokia to Chen Zhen.

Chen Zhen's fox tail was only revealed at this time.

The back cover was pried open and Shen Changjin's SIM card was taken out.

Take off the toothpick from your mouth, poke out the Samsung SIM card slot, and insert Shen Changjin's phone card into it.

Restart the computer to make sure the mobile signal is on, and help him import the address book before he can return it to Chen Changjin.

"Just use this, who will use you, the old guy?"

Xu Zige quickly called the instructor.

The instructor's eyes were confused: "What's wrong?"

"It's done, Chen Changjin has used that phone."

"How to use it?" asked the instructor.

Xu Zige lifted the recording and played it out.

"Okay, it's a good job, so let's take a break?"

"Xiao Xu, you stare at me. I really can't hold on. I'll go back and sleep for a while."

After saying that, the instructor left gorgeously.

Chen Zhen finally ended. When it was his turn to pay the order, there was a total of 230 yuan. Chen Changjin snatched it and he had to rush to pay the order no matter what.

Chen Changjin was drunk: "Brother, I said, I treat you, even if I treat you, it will be easier for you."

They rushed to pay the bill.

He pulled Chen Zhen aside again, took out 300 yuan, and stuffed it into Chen Zhen's hand.

"Brother, you can take this money."

Chen Zhen's cheeks flushed when he drank, but he was particularly sober: "How can this work? I'm short of money when I buy a car."

Chen Changjin refused to give up and insisted on returning the 300 yuan to him.

"Brother, I took your phone number and took advantage of you. If it were my car, I wouldn't want a penny of the money and I'll give it to you directly."

"But you understand, I also have shareholders, and what I say alone doesn't count."

"You have given you a deposit of 200 yuan before, plus the phone number, which is enough. Although it is not easy for me to live, I will never take advantage of you."

Under the luminous light, Chen Changjin's face turned pale even after drinking.

Then suddenly, Chen Zhen was still a little moved.

"Okay, then I won't be polite to you. I'll invite you back another day."

Chen Changjin said, "Okay, okay, then just say it. I'll drink it some more tomorrow, and I'll have to go back first."

"As long as I am a brother, everyone can talk about it. If you get along with me, I will never let you suffer any losses."

"Go away brother."

He handed the motorcycle key to Chen Zhen and said in a daze: "Or, go to my place and sit, I have something good."

"No, I have to go back to the countryside tomorrow, the road is slower."

Shao Bo rode on another car, Chen Changjin jumped into the back seat, and the two went to Baita Mountain.

Chen Zhenze immediately took out his mobile phone, clicked on the monitoring website, and sent a text message to Chen Changjin with a script tool.

"Thank you, Brother Chen, I'll call you another day and I'll invite you back."

A few seconds later, before Chen Changjin replied to the message, he had already prompted that the binding was successful.

A real-life map appeared on the screen, and a small red dot was heading towards Baita Mountain.

Chen Zhen clenched his fist and succeeded so easily?

He quickly returned to the stall and put away the switchblade on the table.

After he picked it up from Chen Changjin's hand, he kept holding it in his hand and played with it inadvertently.

Hold the cup that Chen Changjin had drunk in his hand.

After meeting up, Wang Hongwei turned into coal: "What are you doing?"

"It's done." Chen Zhen lifted the door and got into the car, and sniffed out a sip of alcohol: "I changed his phone card to him."

"What's changed?"

"Captain Wang, didn't you say that you should find a way to let him use that phone? I helped him change the card and I imported the address book for him. He would definitely use it."

"You drank with him for this?"

"Of course, why would I do that?"

"Okay, it's a good job." Wang Hongwei stretched his eyebrows: "Go back and rest for a while, there will be action tomorrow morning."

Wang Hongwei saw Chen Zhen pinching a beer glass with two fingers.

"What are you doing with this?"

Chen Zhen said: "I brought it back by Chen Changjin. If I need to extract fingerprints, this is ready-made."

Wang Hongwei was very happy.

This guy really surprised him repeatedly.

But it's useless.

"Don't throw it away. His cell can be piled up like mountains, DNA, hair, blood, and even dandruff. Not to mention fingerprints, there are several pairs of soles of his feet."

Chen Zhen still held it: "Don't worry about him, take it back."

It was almost 4 o'clock when he returned to the dormitory. Xiao Liu was still sleeping like a dead pig, and Chen Zhen was still sleepless.

He rushed to the desk beside the window, pressed the lamp, placed the beer mug and the switchblade under the lamp.

Take out the stick from the back, and a flashlight, and press it three times at the tail. The white light turns into red light, and then turns into blue light.

Turn off the desk lamp and shone it onto the cup with the blue light from the flashlight, which was covered with a large number of fingerprints.

Chen Zhen was delighted: "It's really useful."

This is not an ordinary flashlight.

It is a spectrum-type multi-band light source that Chen Zhen has obtained before.

Multi-band light sources are also common police equipment. The most basic portable multi-band light sources are essentially flashlights.

Three functions: low light, strong light, explosive flash.

Low light, color temperature 5000K, 200 lumens, is used to check handprints, footprints, fingerprints, fine traces, blood stains, and physical evidence surveys.

High light is mainly used for lighting.

The flash is used when confrontation, and it will blind others' eyes at any time.

A more advanced one is a 5-band light source, which has five types of light sources with wavelengths of red, blue, green, ultraviolet light, warm white light, and 400 nanometers to 635 nanometers.

For example, check for cleaned blood.

Even if the blood stains are wiped and cleaned, the heme in the blood will still remain. Spraying the heme with luminol reagent on the heme will cause oxidation with reactive oxygen species and release blue-purple fluorescence.

At this time, use an orange light source to shine, and the blood will appear clearly.

However, it is necessary to use chemical reagents, zinc chloride, cadmium nitrate, dichlorofluorescent agents, etc.

Chen Zhen, who has mastered the low-light tactical manual, has transformed into a survey expert and pressed a 450-nanometer blue light source, and dense sweat and dirt fingerprints crawled all over the cup.

Logically speaking, it is a bit troublesome to extract fingerprints at this time.

You need to use red phosphor and fingerprint brush, first brush the colorless fingerprint to fluoresce, and then use a fingerprint sticker to collect it.

Or, use a professional criminal investigation camera to take photos with an orange filter to obtain a JPG picture, then convert it to a PNG picture, use PS to adjust the color, and extract pure fingerprints before entering the computer.

But Chen Zhen doesn't need this.

It can be collected automatically.

Chen Zhen kept the light still, took out his mobile phone, logged into the system website, clicked out the bound spectrum multi-band light source APP, and clicked to scan and enter.

The phone is quite thoughtful and the prompts pop up.

"Is it allowed to retrieve camera permissions when an unknown application was detected?"
To be continued...