The next morning.

Municipal Public Security Bureau, Han Bin's Office.

There is a table of materials on the desk, all of which are sent by Zheng Kaixuan, and Han Bin personally printed them into documents, although they can also be viewed on the computer, but the paper materials are more convenient to study.

The person involved in the case is Bao Jiansheng, 45 years old this year, a suburb of Quancheng, who was suspected of participating in a burglary and murder case 14 years ago, but the chain of evidence has been insufficient to convict.

Among them, there is a very important clue is a group of shoe prints found at the scene, that group of shoe prints has been printed out by Han Bin for careful study, this is a rubber-soled shoe, which is rare now, but it was very popular more than ten years ago.

Bao Jiansheng's footprints were also collected by the police, and in order to facilitate identification, they were also printed in rubber-soled shoes, but they couldn't find exactly the same shoes in the past ten years, so they had to retreat to find shoe prints with similar patterns.

I started researching since yesterday afternoon, and I have been studying until this morning, the comparison of these two sets of shoe prints is still quite interesting, in order to increase accuracy, Han Bin also asked Zheng Kaixuan to take a few photos of the wear and tear marks of the soles of Bao Jiansheng's old shoes.

At ten o'clock in the morning, Han Bin finally got the result, picked up his mobile phone and dialed Zheng Kaixuan's number.

Zheng Kaixuan's voice rang in the mobile phone, "Binzi, is there a result?"

"Yes, I'm done. ”

Zheng Kaixuan asked, "Do the footprints at the scene of the crime more than ten years ago match Bao Jiansheng's footprints?"

"Not exactly. ”

Zheng Kaixuan's tone was a little lost, "So we caught the wrong person." ”

Han Bin didn't answer and asked, "Team Zheng, you answer me a question first, is this man named Bao Jiansheng injured in his right leg?"

Zheng Kaixuan hesitated, "Yes, it is true that he has been injured, as far as I know, his leg has been broken, and he has also undergone surgery." ”

"When did he hurt his leg?"

"It was about five years ago. ”

Han Bin said, "According to my research, the footprints at the scene of the crime fourteen years ago should have been left by Bao Jiansheng. ”

Zheng Kaixuan was a little stunned, "Didn't you just say that these two sets of footprints don't exactly match?"

Han Bin changed his words, "Although the footprints do not match exactly, they are indeed shoe prints left by the same person." ”

"Binzi, tell me in detail, what do you mean?"

Han Bin explained, "Footprint identification is different from evidence such as DNA and fingerprints. Human DNA and fingerprints do not change, but footprints are not static, and with age, physical condition, and mentality, people's footprints will also change.

These two sets of footprints are separated by fourteen years, and what happens in these years will affect and change a person, how can it be the same. ”

Zheng Kaixuan asked, "If, according to you, Bao Jiansheng's footprints have changed in the past fourteen years, then how do you know that it is the same person's footprints." ”

"This is more complicated, let me give you a few examples, first of all, the length of the foot, which basically does not change. Another change in the footprint is traceable, and it can also be reflected in the human body.

From the information you gave me, it can be seen that Bao Jiansheng now weighs about 180 pounds, while more than ten years ago his weight was only 120 pounds, his weight has increased by one-half, and more than 60 pounds of flesh is on his back, and his walking posture, stride distance, and gait will change.

Moreover, he suffered an injury to his right leg five years ago, which will also affect his walking posture, which also increases the difficulty of identification to a certain extent.

Coupled with the fact that the foothold of the footprint shifts backwards as we age, these changes are traceable. Han Bin paused and continued,

As long as these conditions for changing the footprints are reversed, it will be found that Bao Jiansheng's footprints are basically consistent with the footprints at the scene of the crime. ”

Zheng Kaixuan roughly understood what Han Bin meant, "With your words, my heart is steady, but you have helped me a lot." ”

"Team Zheng, after all, this is just my personal experience analysis, you'd better ask experts from the provincial department to help you identify, their words are much more useful than mine. Han Bin said with a smile.

Zheng Kaixuan smiled bitterly, he really wanted to ask experts from the provincial department to help issue a footprint appraisal report, and it could be used as evidence, but that expert Liu couldn't see it accurately, Ma Lao didn't know what to wait for before he could be discharged from the hospital, and he couldn't keep delaying it.

"It's okay to be late for the appraisal certificate, I can wait for Ma Lao to be discharged from the hospital. The key is that your appraisal results have made me feel at ease and clear about the direction of the next investigation. Otherwise, the police will go out and finally get an oolong, and I won't be able to explain it. ”

"Brother, if you want me to say that it is more than enough to qualify as a provincial department footprint identification expert with your skills, and in the future, brother, I will find you to issue an appraisal report, so how much trouble will it have to be saved." ”

Han Bin smiled, "Team Zheng, don't promote me, the name of an expert is so easy to get, I still investigate my case in a down-to-earth manner." ”

"You've got it all figured out. Zheng Kaixuan thinks about it, Han Bin is a criminal policeman, footprint identification belongs to the technical department, the two are not one department at all, the police system is staffed, a person from an external department wants to obtain the title of an expert in other departments, where is it so easy, even if you are really capable? There are many capable people, you have to cross the threshold first and become your own person, otherwise everything will be in vain.

Of course, this is not absolute, when a person stands high enough, the so-called threshold will become his stepping stone.

Thinking about it another way, Han Bin is the squadron leader at such a young age, and in a few years, his achievements will be higher, and he will solve several well-known major cases, and he will be proficient in footprint identification.

The two chatted for a while, and Han Bin mentioned Bao Xing, "Team Zheng, I have a colleague named Bao Xing in the city bureau, the young man is good, and he has been handling cases under me." I was transferred to the provincial department a few days ago, I should be in the criminal investigation team, if you see it, help me take care of it. ”

"Bao Xing, right, I made a note of it. When I got back to him, I'll talk to him. Someone on the other end of Zheng Kaixuan's phone seemed to call him, "Brother, I'm busy, let's talk later." ”

"Good. Han Bin answered, and then hung up the phone.

The reason why he mentioned Bao Xing was not a temporary idea, after all, they all went out of Qindao, and the relationship between the two of them and Han Bin was good, one was Han Bin's leader, and the other was Han Bin's subordinate, and it was also good for Han Bin for the two of them to have a good relationship.

These two people are in the provincial hall, maybe Han Bin will be able to use them in the future.

As for asking Zheng Kaixuan to take care of Bao Xing, it was just a rhetoric to match the two, Bao Xing was transferred to the provincial department by virtue of his father's relationship, and his father's position is higher than Zheng Kaixuan's, and it is really uncertain who will take care of whom in the future.

After finishing his work, Han Bin cleaned up the table and smashed all the documents on it, the criminal investigation team of the provincial department is a big case, and Han Bin doesn't want these materials to circulate from his hands.