This time the express left two clues, one is the movement track, and the other is the express mail. Pen ~ fun ~ pavilion www.biquge.info

A large number of police forces were put into the investigation work, and at the same time, a detailed investigation of the express letter began, and the investigation mainly focused on three key exhibits.

First of all, the mineral water bottle was carefully inspected, although only the fingerprints of the front desk, administrative manager, Liang Yongqing and other unrelated people were found on it, but it was very fortunate to extract more than a dozen kinds of dander and biological tissue residues on the mineral water bottle, including a saliva residue.

This was the key clue, and the tissues were sent to monitor the DNA, and the results were quickly in.

The DNA of these biological tissues and dander came from five different people, and the most of the remaining samples were from a complete stranger, and it was this DNA that left saliva behind.

This person is likely to be the sender, it is easy to imagine the situation at that time, maybe when preparing this thing, this person picked up an empty mineral water bottle at hand and began to make the shipment, although he carefully erased his fingerprints, but it was difficult for him to remove the biological residue, so these were brought to the secret service.

The second is the letter of the A4 printing paper, this letter reveals a lot of information, first of all, the ink, the chemical composition of the printing ink of each manufacturer is different, the printing ink in the font is analyzed at the molecular level, and then compared with these inks that often appear on the market, and soon find one of the batches of ink of a certain ink manufacturer The ink is the same as the ink on the printing paper.

With this batch of ink as a clue, the whereabouts of the ink began to be traced, and the ink was finally sent to three provinces and regions, and the agents who distributed this batch of ink in these three provinces and regions were framed.

Continue to track down the sales of ink, and lock down the person who appears under the surveillance camera at the time of each sale. Extract their video footage and compare it with the portrait of the person at hand.

The origin of the paper can also be traced, and the type and content of chemicals used on the paper are implemented differently by each paper mill, and even under the same set of technologies, there will be differences between different batches.

With this discrepancy, it is easy to pinpoint the source of the paper, and in conjunction with the sales area of the ink, a sample of the paper that has appeared in these areas is collected, and the manufacturer and production batch of the paper are quickly searched.

Then search the sales area and distributor of this batch to find the degree of overlap with the ink distributor, use this degree of overlap to retrieve the corresponding monitoring, and find the person who can be compared with the portrait.

The third key piece of evidence is the courier note, which is filled out by the suspect himself, and the font left on it can reveal a lot of information.

The font on the courier slip was sent to an expert who specialized in note analysis, and soon a psychological portrait was enough:

...... This is a young man, between the ages of 22 and 27, who lives a relatively simple life, does not have overly complicated social relationships, has little social experience, may be a student in school or in a position that does not have frequent contact with people; This person is introverted and unsociable, similar to a technician's personality; This person may have achieved a little, show a certain amount of self-confidence and control between the strokes, be satisfied with the existing life, have a hopeful heart, he has been in a high mood lately, he may have encountered some happy events or is in a successful relationship; If it was the latter, maybe his girlfriend would be more beautiful, far beyond his psychological expectations......

A series of information is put together, and the Secret Service needs to synthesize all of this information, and then compare all the screened people to look for possible suspects.

At this time, the entire secret service department felt a huge workload, as well as extremely low efficiency, at this time Liu Huaiyi couldn't help but start to miss the big data system that Li Menghua was developing, if there is the help of the computer, these jobs are just a matter of pressing a few buttons, right?

At this time, Liu Huaiyi also understood that in this kind of case like looking for a needle in a haystack, it is more important than anything else to have a good auxiliary detection software at hand, and a software is often worth hundreds or even thousands of well-trained agents, the key is that it does not know fatigue, it is always accurate, and the data can be fully compared with each other, which is much stronger than a single individual agent in information exchange and comparison.

Now that the big data software has not been developed, the secret service department can only simplify because of the ugliness, and keep investing manpower, just rely on people!

The surveillance video of the ink dealer and the paper dealer was searched several times, but no useful clues were found, and only DNA, psychological portraits and portraits remained.

After carefully interviewing thousands of people, five people reported seeing the person in the portrait, or the person in this dress.

The five men were brought back to the Secret Service for an in-depth investigation, and after various instrument tests, as well as hypnotic awakening memories, it turned out that three of them were false positives, all due to false memories formed by the police's misleading language.

This phenomenon is relatively common, and some people have done statistics that the error rate of victims in the process of describing the appearance of the offender and identifying the offender is often as high as 60%.

Because the human brain memory has the property of reprocessing, the first visual picture obtained by a person, when this picture enters the human brain, must first be processed once, and then it can be classified and stored.

How does this process work?

First of all, a picture enters the brain, and the brain begins to recognize this picture, compare the difference in binocular vision, transform the flat image in the picture into a three-dimensional figure, and form a three-dimensional cognition of spatial position in the brain, and at the same time, the different color blocks and lines in the picture begin to be classified into this three-dimensional figure, which belongs to an object, which belongs to another object, which is the ground, which is the house, and which is the human body, which needs to be processed by the brain step by step.

Camouflage uniforms, spatial optical illusions, are the use of this characteristic of the brain to confuse the brain and form false cognition and classification.

There is also the kind of scribbling that specializes in deceiving the brain, and many people will see completely different patterns after seeing it, which is caused by different processing results of different people's brains in the process of visual abstraction, classification, and generalization.

Because the memory formation of the human brain is a visual signal reprocessing process, it will be affected by many factors, and after verbal cues, a person will often modify his memory beyond recognition.

The three people who gave false positives belong to this category, they have not actually seen the suspect, but the police bring the portrait to them, they look at the painting carefully, and unknowingly process a false memory in their brains, thinking that they have seen this person at some point.

The false positives were eliminated, and the two people who had actually met were left with very leisurely valuable information, they could only remember the approximate vague time period, and they only knew which direction the person was going from, and there was no other valuable information.

Next, a detective suggested that since there is a printing paper, then there are two kinds, one is that this printing paper was printed by the suspect in his own home or his workplace, and the other is that he printed it on the road, since the courier delivery location has been locked, so why not search the surrounding typing and copying shops?

This is an idea, the five-kilometer radius of the print shop with the express point as the center of the circle was included in the search scope, and the local police visited the past one by one, but the result was still nothing, and no trace of the suspect was found.

At this point, the case is once again at an impasse!

PS: Today's update is awesome, right? Comrades also give me a little strength and support me fiercely!