Chapter 763 The Criminal Returns to the Scene for the Second Time

Back at the Criminal Investigation Department, Chen Shu came to Huang Mao's office and asked Zhu Yiba and Huang Mao if they found anything unusual in the video surveillance.

Video investigation is a technical job. It is handled by specialized technicians in the Criminal Investigation Brigade. In places where individual cases occur frequently, a special video investigation squadron will even be established.

There are two tasks. One is to go to the scene and search for civilian videos near the crime scene. All video surveillance of the scene must be copied one by one;

The second is to sit in the office, pour yourself a pot of tea or make two cups of coffee, and then spend a long time on analysis. If you have to compare, it is a bit like playing an advanced version of the "Find the Difference Game", which consumes brain cells and eyes.

Ordinary people think that video investigation is to check surveillance, and think it is a simple matter, just staring at the display screen to find the suspect.

In fact, it is not the case. There is a lot of knowledge in it.

For example, the Public Security University and the Criminal Police College have opened a special video investigation major for local visual investigation personnel to study and further their studies. They are often held in several sessions, because it is impossible to explain it clearly in a single week.

And with the development of science and technology, the information technology it covers has increased exponentially. After all, it is a new technology and is still a blue ocean in this field.

In addition to the necessary knowledge, checking surveillance and pulling call records are similar, both of which require sufficient patience and a long time, and neither is indispensable.

After getting the answer that everything is normal for the time being, Chen Shu copied the video to another computer and started the video investigation work at the same time, but he only picked the camera in the corridor where the crime scene was located.

Then, he started to watch it slowly frame by frame.

He stared at the screen for a moment without blinking, but Chen Shu's mind was turning rapidly, thinking about the connection between the curtain cloth and the mud grass.

Curtain cloth, mud grass;

Upstairs, downstairs.

The three of them stayed in the office for a whole afternoon without finding any clues, and Ma Rongcheng came back from the on-site re-inspection with a bunch of fingerprints, and planned to throw them all into the fingerprint database later.

At that time, the person corresponding to the fingerprint will be compared with the information of the hotel's check-in personnel. If there are extra people in it, it is likely that they are suspects.

In the eyes of Ma Rongcheng, a professional technical police officer who came from the provincial department to support, this is a relatively stupid method, which does not reflect his status as an expert.

Ma Rongcheng patted Chen Shu on the shoulder and motioned him to move.

After sitting down, Ma Rongcheng typed in a URL, then uploaded the copied hotel video to the website, and finished it by hitting Enter.

Looking at the steadily rising progress bar and percentage on the screen, Ma Rongcheng smiled easily, showing the demeanor of a master, and then took a few people downstairs to eat.

In the restaurant, Ma Rongcheng raised his chopsticks and introduced it with a little pride.

"Woan Intelligent Video Detection System, supported by modern technologies such as big data, cloud computing, and the Internet of Things, and artificial intelligence research and judgment as a means, integrates various digital services of the public security intranet, and comprehensively perceives and comprehensively analyzes"

"Teacher Ma, is this the Sky Eye system recently launched by our Ministry of Public Security?" Jiang Hai continued to maintain a student's learning attitude.

Ma Rongcheng smiled and replied: "It's different. The Sky Eye system integrates our own surveillance equipment, while the Woan system is mainly used to analyze civilian surveillance videos."

The two people's question and answer also made Chen Shu and others who were listening sigh. With the development of social science and technology, various investigation technologies are emerging in an endless stream. This is something that can really help.

Unlike the early years, the police, except for the uniforms they wear, are basically forced to investigate cases, using the most rustic methods, such as investigation and visits.

The expenditure of police force, material resources and financial resources and the severity of the case are not proportional at all.

After the meal, the group returned to the office, and the computer already had the results of the system analysis.

Jiang Hai respectfully pulled out the chair and let Ma Rongcheng sit in front of the computer as if he was alone. The others stood in a semicircle behind the expert and looked at the analysis report in the computer together.

The words on half of the screen were written, but after a closer look, there was nothing.

According to the conclusion given by the system, in the videos within 20 days of the crime, this intelligent system, which is said to have spent astronomical amounts of money to develop, did not find any suspicious persons.

Everyone was inevitably a little discouraged.

Considering the possibility that the suspect may return to the scene for the second time, Chen Shu proposed to copy the video surveillance data within one week after the crime to the software for analysis.

The second return to the scene mentioned here means that after the criminals leave the scene of the crime, there is a high probability that they will return to the crime scene after a period of time.

This is supported by real cases, and there are quite a few.

The first category is that criminals may have a high tendency to seek excitement. The purpose of their crimes is to seek adventure and excitement, as well as inner satisfaction.

After leaving the crime scene, they return to the crime scene again. This behavior will psychologically give them a stronger sensory stimulation than when they committed the crime.

The second category is that criminals return to the scene to confirm the results of their previous criminal behavior. For example, whether there is evidence left at the scene that can identify them, or to destroy the evidence they accidentally left when they committed the crime, or to observe the progress of the police investigation.

From a psychological point of view, it is to escape the crackdown by the police.

It is probably the above two categories. The first category is extremely rare, and most of them belong to the second category.

Jiang Hai, who also belongs to the police academy, seemed to understand, and habitually moved towards the direction of Chen Chuan next to him. After approaching, he whispered: "Brother Chuan, why do these people return to the scene full of police after committing crimes? Isn't this looking for death?"

Chen Chuan hugged his chest, squinted his eyes at his junior brother, and said disdainfully: "Little guy, recall, do you look back after taking a shit?"

The words are rough but the truth is not rough.

Jiang Hai was shocked, but he really recalled it.

After reacting, he was a little confused. This young student of the police academy didn't know whether it was right or wrong to ask this unreliable senior brother questions.

Here, as an expert, Ma Rongcheng immediately agreed with Chen Shu's suggestion, and then asked Huangmao to go to the hotel to retrieve the recent videos again. After Huangmao came back from the hotel, he put the videos into the software for another analysis.

The computer fan was blowing hard like an old cow panting, but the result of the analysis was still that no suspicious person appeared.

Ma Rongcheng was embarrassed. He had just praised the Woan system for half a day, but after a fierce operation, he didn't get anything useful. This expert from the provincial department couldn't help but feel embarrassed. He felt that the chair under his butt was hot.

"Why don't we let Old Tang dissect the body?" Ma Rongcheng chose to escape and suggested.

Jiang Hai immediately took out his mobile phone, and was actually looking forward to it. However, he knew that he couldn't make the decision, so he asked in a tone: "I will contact Teacher Tang when I come?"

As he said that, he suddenly lost some of his temper and muttered: "I guess the family members may not agree to the autopsy."

Ma Rongcheng looked at the little brother in front of him with an unusually rich expression, and said happily: "For the autopsy of abnormal death, you only need to notify the family members of the deceased, and you don't need to get their consent."

"Is there such a thing?" Jiang Hai jumped up, picked up the mobile phone and dialed, but his eyes were looking at his senior brother beside him.

Chen Shu didn't express his opinion, but just stared at the analysis report on the computer monitor, pinched his chin, and thought.

I have to say that this Woan smart video is quite good. Although the analysis conclusions seem a bit rigid and mechanical, some tedious data are clearly counted by this system.

When the table is pulled, the time, place, and people are clear.

After connecting to the personnel information of the public security intranet, as long as the face is clearly revealed in the surveillance, even those wearing masks, their personnel information can be displayed one by one.

Then behind each person, the total length of time they appear in the surveillance is marked.

Click on the name, and a list of the time points and corresponding videos of this person appearing in the video will pop up.

The top few are naturally hotel staff, and the subsequent ones are Kunming locals who often come to the hotel. According to normal investigation logic, these people should be checked one by one.

But Chen Shu and his team are police officers from other provinces after all, and this kind of investigation work is not easy to start without authorization.

Chen Shu stared at the names on the screen and subconsciously looked at the first one, that is, the person who stayed in the video the longest.

Zheng Amei.

As a hotel cleaner, Zheng A-mei's job is to clean the rooms checked out by guests on each floor. The staff who runs up and down is naturally the staff who has been there the longest and has passed through the most areas among all people.

This person is also the first person to discover the murder scene.

That day, since Chen Shu, Chen Chuan, Jiang Hai and others were all at the scene, after Zheng A-mei opened the door and found the body and screamed, the three of them quickly entered the room and found the deceased.

Therefore, Chen Shu and others took it for granted and subconsciously thought that they were also the first to discover the body, thus ignoring Zheng A-mei who discovered the body first.

This hotel staff with a very low sense of existence.

The problem lies here.

Chen Shu raised his eyebrows, and the case seemed to be beginning to take shape, but he also knew in his heart that the real challenge had just begun.