May 25th, 2:00 pm.

The Kasai Police Department, the Physical Evidence Technology Laboratory on the second floor, Qin Yun, an international student from Xia Guo, is asking Nanlin Guiyi for advice on how to extract fingerprints on the surface of soft objects.

For example, how should the fingerprint of an inner page of a book be extracted?

Extraction of fingerprints is one of the important skills of physical evidence technicians. It will be used at various case handling sites, whether it is a serious murder case or an ordinary theft case.

Generally speaking, there are two types of fingerprint extraction schemes.

The first type is the area where fingerprints are left are non-water-absorbent areas, such as metal surfaces, glass surfaces, porcelain surfaces, or plastic surfaces.

The surface of these non-absorbent materials leaves fingerprints. The method of extraction is relatively simple. You can use the powder method. The so-called powder method is to sprinkle fine powder with a large color contrast difference in the area where fingerprints may be left, and then use a soft fine brush to brush the powder off to get the fingerprint.

This method has a very high appearance rate among all kinds of film and television works!

The second type of fingerprint extraction is more complicated. It extracts fingerprints that may be left behind on water-absorbing materials. The question Qin Yun asked for is this type.

Nanlin Guiyi explained it to Qin Yun, including silver nitrate method, iodine fumigation method, fluorescent reagent method, and Haidelin method. The iodine fumigation method is mentioned in junior high school chemistry textbooks in some countries.

The other three methods are also available in various film and television works.

"Senior Guiyi, can you demonstrate the iodine smoke method?" Qin Yun looked at Nan Lin Guiyi with pitiful eyes. Her eyes were big, as if she could speak, which made it difficult to refuse.

Nan Lin Guiyi thought about it for a while and finally nodded in agreement, "Yes!"

The iodine smoke method is commonly used, and there are a few tricks when processing is completed and fingerprints are displayed. Some newcomers often forget the final processing work.

Nan Lin Guiyi had no idea of ​​hiding his own private life. After all, Nan Lin Guiyi was not prepared to be limited to the physical evidence class. He has now officially transferred to the fourth team of the search class.

"Thank you Senior Guiyi!" After Qin Yun finished speaking, he quickly took out a piece of A4 printing paper and continued, "This is the sample I asked Fukuda Kato before, which contains the fingerprints of Fukuda Kato. Senior Guiyi, what should we do now?"

Nan Lin Guiyi did not take the a4 printing paper, but first put on light blue rubber gloves before taking the a4 printing paper, and said to Qin Yun: "As a physical evidence technician, the first core principle is to protect the physical evidence from damage! You have destroyed it by holding physical evidence that may contain important fingerprint clues!"

Qin Yun quickly apologized, "Sorry, Senior Guiyi, I remember!" She said, put down the A4 printing paper, and then quickly put on light blue rubber gloves.

Nan Linguiyi picked up the A4 printing paper, observed it first before continuing to explain, "Do you know any preparations for doing the iodine smoked fingerprint extraction?"

Just as Qin Yun was about to answer, a dull explosion came from downstairs.

"Bang~"

At the same time, there was a noisy noise coming from the first floor, and something obviously happened!

Nan Linguiyi's face changed slightly. Although the explosion sounded downstairs was not loud, what was important was that Butler reported the information to Nan Linguiyi in the skinny conduction headphones.

"Private, the system detected that the police system of the Kasai Police Department was controlled, and the invading personnel were injected with a destructive virus and was destroying the security monitoring system. The system predicted that the security system of the Kasai Police Department would be offline within ten seconds. Countdown."

This message is the reason why Nan Lin Guiyi's face changed!

The Kasai Police Department has been calm recently and nothing has happened at all, but what is happening now is obviously abnormal.

Could it be that the S organization has discovered something?

"Senior Guiyi, what happened?" Qin Yun followed Nan Linguiyi nervously. Perhaps because of fear, she grabbed Nan Linguiyi's arm.

A hint of helplessness flashed in Nan Linguiyi's eyes. Qin Yun was too close to him. He wanted to contact Butler, but he could not hide it. In order to avoid exposure, Nan Linguiyi could only give up contact with Butler.

"I don't know, you're waiting for me here, I'll go down and take a look!" Nan Linguiyi comforted Qin Yun and naturally left Qin Yun.

However, before Nan Lin Guiyi went downstairs, four dull explosions came almost in sequence. If Nan Lin Guiyi had not been able to judge at all.

Of course, even if Nanlin Guiyi cannot judge, Butler can judge by skin-conducting headphones or mobile phone microphones.

‘Damn it! What happened!’ Nan Lin Guiyi was originally going downstairs to check it out, but the current situation made Nan Lin Guiyi alert.

Nan Lin Guiyi returned to the physical evidence technology laboratory, greeted Qin Yun, and whispered: "What's wrong, come here!" He took Qin Yun and hid behind the workbench of the physical evidence technology laboratory, and at the same time took a bottle of nitric acid as a defensive weapon.

"Senior Guiyi, are we in danger?" Qin Yun asked nervously.

"Shh!" Nan Lin Guiyi made a silence move, took out his cell phone, lowered his voice and said, "Take out the cell phone, set it completely silently, don't even shake it!"

How many people who are hiding are discovered because of ringtones or vibrations of mobile phones?

Nan Lin Guiyi couldn't figure out the situation now and had no idea what happened in the Kasai Police Station. However, there was a noisy noise downstairs just now. After four dull explosions, the noisy sound gradually disappeared. Nan Lin Guiyi had already raised his vigilance.

Qin Yun set his mobile phone to a safe and silent state as Nan Lin Guiyi's instructions, and then carefully hid beside Nan Lin Guiyi. However, Nan Lin Guiyi did not notice that there was no tension or any uneasy fluctuations in Qin Yun's eyes.

Nan Lin Guiyi held his mobile phone and quickly edited the text message. While editing the text message, he naturally turned his head to prevent Qin Yun from seeing his lips, and then quickly contacted Butler.

"Butler, search for the location of Kato Fukuda, control Kato Fukuda's mobile phone, set the silent and vibration frequency, and reduce the vibration intensity." Nanlin Guiyi ordered that he did not know about Kato Fukuda's situation, so he could only mute Kato Fukuda's mobile phone and reduce the vibration intensity so that when he sent the message, Kato Fukuda could know it, but to the greatest extent, he did not attract attention.

"Private, the setting has been completed." Butler feedback.

After receiving Butler's feedback, Nan Linguiyi confirmed that he sent a short message, and then naturally changed the angle of the head turn, without any abnormality at all.

"I have sent a message to ask Senior Kato, and now I'm patiently hiding." Nan Lin Guiyi responded.

Qin Yun nodded affirmatively, "Okay!"

As for Kasai Police Station, Nanlin Guiyi really doesn't know what happened, so he can only wait for Kato Fukuda's response.

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