In recent years, in the investigation and handling of various criminal cases, the role of the investigation has become more and more significant.

From a part-time job more than ten years ago, any criminal police officer can come up and show his hands, and now it has developed into a specialized department category.

In particular, the criminal investigation detachments of local municipal bureaus have basically set up professional teams for on-site investigation, and most of the trace verification is two sets of brands and one person.

This is the case with the Haizhou City Criminal Investigation Detachment, where the on-site investigation and later evidence verification were all completed by Liu Guodong and the four of them.

Of course, there are also some awesome criminal investigation detachments, there are more than a dozen people in the current investigation, and there are more than a dozen people in the trace inspection, which is generally at least the provincial capital level detachment.

As a common extraction information in field survey, footprint analysis has gradually developed into a specialized discipline.

However, whether it is the Public Security University or the front-line criminal investigation detachment, there is an extreme shortage of talents in this area.

There are many reasons for this, on the one hand, it is not a systematic teaching, on the other hand, there are some skills that everyone cherishes, and on the other hand, there is limited room for career advancement.

If someone is willing to teach, there may not be someone who wants to learn.

Compared with fingerprint identification, footprint analysis is relatively backward.

Therefore, Lu Chuan's acquisition of footprint analysis skills through the system is relatively rare, although it is only rudimentary.

However, even if it is a beginner, it can only be said that there are some things that Lu Chuan has not mastered very well, but it does not mean that the skills rewarded by the system will be wrong.

Footprint analysis has many doorways from measurement.

The first is the determination of the imaginary edge, a shoe print, and the center of gravity is concentrated in the palm of the hand.

However, because the human foot has an arch, it is normal to say that the middle of the shoe print is the shallowest mark, and the scarlet mark on the sole and heel of the foot is the heaviest.

Then take the palm of the foot as the center point, and the outward you go, the shallower the traces of the shoe print, and the dotted edge will form at the edge.

The size of the dotted edge of the same size of shoes means that the weight of the owner is different.

The greater the weight, the smaller the imaginary edge.

Combined with the length of the shoe print, the height and weight of the owner of the shoe print can be calculated by calculation.

However, in this case, the shoe prints left by the suspect were irregular before and after, sometimes large and sometimes small.

Although the difference is very subtle, it can still be measured.

In this case, it is very likely that the other party is wearing shoes that do not match the actual number.

At the same time, the imaginary edges on the left and right sides of the soles of the feet are also different.

In other words, the other party's shoes should not only be larger in length than the actual number, but also in width.

Combined with the length of the stride and the weight calculated by the depth of the footprints in the state at that time, Lu Chuan determined that the owner of the footprints was a woman.

It's just that I wore a pair of men's shoes, and they were one size bigger.

No wonder you can't find the suspect, the gender is all wrong, how can you catch someone?!

Repeating the calculations to make sure that his judgment was not wrong, Lu Chuan continued to speculate on the physical characteristics of the suspect based on the data of the shoe prints.

"The inner edge of the shoe print is slightly heavier, and the outer edge is slightly lighter...... The other party is an X-shaped leg. ”

"Excluding the influence of imaginary edges, the length of the opponent's foot should be 24.2 centimeters...... The height is about 1.69 meters, and the weight is about 61 kilograms......"

An hour later, the suspect's features had been marked in detail.

Female, 1.69 meters tall, 61 kilograms in weight, between 32 and 37 years old, X-shaped legs.

"Ding"

"The basic task was completed, and the host used footprints to analyze the physical characteristics of the suspect in the robbery and wounding case."

The moment Lu Chuan completed the calculation, a prompt sound appeared that the system had completed the basic task.

Next, Lu Chuan opened another pile of information, which was all the surveillance data near the location of the crime at that time.

During the time of the robbery, a total of 32 people were captured.

Of course, the suspect did not necessarily go through the surveillance that collected portraits at the time, and this is only an investigation data.

Lu Chuan flipped through the information and compared the portrait photos one by one.

Within a few minutes, Lu Chuan's eyes were locked on a woman named Zhang Yan!

"Hey, it's you!"

Holding the woman's photo, Lu Chuan locked the door of the current survey warehouse and went directly out of the criminal investigation detachment.

"Lao Yang, are you in the office?"

Unlike Lu Chuan, who was assigned to the criminal investigation detachment, Yang Lin was assigned to the police station after graduation and became a police officer.

Coincidentally, Zhang Yan's place of residence is in the area that Yang Lin is in charge of.

Wah Kwong Street Police Station.

Yang Lin poured tea for Lu Chuan and took Zhang Yan's information: "This person lives in a low-rent house, I'll check the information." ”

With the relationship between the two, there is naturally no need to be polite, Lu Chuan directly explained the intention: "This Zhang Yan is a suspect in a robbery and wounding case last year, you see if you can collect her footprints, if you can compare them, this backlog of cases will be solved." ”

"No problem, you sit down first, and I'll be back shortly."

Although the work in the police station is complicated, it is relatively easy.

Generally speaking, most of the cases handled by the police station are neighborhood adjustments, petty theft, and the like.

Once eight types of major criminal cases occur, they must be handed over directly, and the police station generally only does some work to cooperate with the investigation.

Of course, this does not mean that the police station must not be able to investigate criminal cases, and if some cases are not solved for a long time after they are handed in, the police station can also apply for return.

Of course, a homicide is impossible, and no police station has gone back to apply for a homicide.

Yang Lin, like Lu Chuan, was born in a professional class, and most of the work in the police station was relatively simple for him.

In less than two minutes, Yang Lin took a pile of materials and handed it to Lu Chuan: "This Zhang Yan works in Anping Electronics Factory, raising a daughter with a single parent, and has a paralyzed mother at home to take care of. ”

Who to help?

Lu Chuan didn't expect that Zhang Yan's family background was so poor.

"I have just contacted the electronics factory, Zhang Yan is still at work, do you think we should go now or wait for her to get off work?"

After reading the information, Lu Chuan thought for a while: "Now, let's go directly to the electronics factory." ”

Twenty minutes later, Anping Electronics Factory.

The workshop supervisor took Lu Chuan and the others to the workshop: "Comrade policeman, the one standing next to the workstation and wearing blue overalls is Zhang Yan." ”

"Let's collect footprints first."

This is simple, Lu Chuan brought a special footprint collection paper, and he only needs to stand on the printing paper for a short time to complete the footprint collection.

After Zhang Yan stood on the printing paper, Lu Chuan carefully observed the other party's expression, and could obviously see that the other party was nervous, his fingers were even trembling slightly, and his face was a little pale.

Sighing secretly, Lu Chuan picked up the collected footprints and directly compared them with the footprints found at the scene of the robbery.

Footprints are the same as fingerprints, and the footprints left by each person are different.

If the two footprints can match, it can be determined that Zhang Yan is the murderer.

"Police...... Homosexuals...... Don't look at it...... That person is me......"

Just when Lu Chuan was comparing, Zhang Yan behind him explained in a trembling voice.

Criminal Investigation Detachment.

Qin Yong looked at Liu Guodong, who was reporting to him, in a daze: "Do you say it again?" ”

Liu Guodong was also confused: "Lu Chuan called just now, and he said that at the Huaguang Street Police Station, he and the police caught the murderer of last year's robbery and wounding case. ”