In the hiking bag behind Zhang Dongsheng, there was indeed a pair of sneakers.

Forensic Gao An immediately put on gloves and took out the sneakers, he looked at them carefully, and said: "It's the same pair as the one on the deceased's feet, and the size is the same!" ”

"Mr. Zhang, why don't you explain why you have a pair of sneakers in your bag?" He Jiahui asked.

"I was worried that my shoes would break during the climb, so I brought an extra pair of spare, can't I?" Zhang Dongsheng argued.

"Then why is it the same as the one on the feet of the deceased?" He Jiahui continued to ask.

"What about the same one? I liked my father-in-law's sneakers, so I went and bought the same one! Zhang Dongsheng is still quibbling.

"Mr. Zhang, what size shoes do you wear? The shoes in your bag don't look the same as your size! Rather, it is the same as the shoe size of the deceased, how do you explain this? He Jiahui asked with a sneer.

"This ......" Zhang Dongsheng was stunned and continued to defend: "Actually, these shoes were brought to my father-in-law, and I was worried that his shoes would break during the climbing, so I prepared an extra pair!" ”

Zhang Dongsheng was obviously completely panicked, and his speech became more and more inconsistent.

However, everyone is not stupid, Zhang Dongsheng's defense confirmed his suspicion.

He Jiahui showed a helpless expression, he let out a long sigh, and said, "Mr. Zhang, it seems that you don't know anything about the current technology. In the face of modern technological means, these justifications of yours are too weak and weak.

You must know that even the same kind of soil, in different environments, such as sun and wind, will have different changes, not to mention that the soil will be mixed with tiny particles such as pollen and seeds, which can be tested.

Forensics only needs to take a sample of the soles of your shoes and compare them with the soil on the cliff to prove whether the soil on the sole is the same as the soil on the cliff.

If the soil on the soles of these shoes is the same as the soil on the cliff, and the soil on the soles of the deceased's shoes is the same as the soil on the cliff, then I can prove the inference I just made.

Only one set of footprints were found on the cliff, and if the soles of two pairs of shoes were stained with the same soil, and the shoes were of the same style and size, the only explanation is that the owner of one of the shoes had forged the footprints. ”

"The one who forged the footprints is either the dead or you." He Jiahui said, looked at the deceased not far away, and then said: "You can't expect a dead person to fake the scene, right?" ”

These words broke the last trace of luck in Zhang Dongsheng's heart, and there was a trace of despair in his eyes, and then he sat on the ground with his legs spread.

"That's right, I killed my father-in-law, I pushed him off the cliff!" Zhang Dongsheng finally confessed to his crime.

"He is your father-in-law, your relative, why did you kill him?" He Jiahui asked with some curiosity.

Zhang Dongsheng raised his head and sighed: "It's all my fault, I lost the bet, and as a result, I owed a gambling debt, and in order to repay the debt, I borrowed a loan shark, and then the interest rolled, and I really couldn't pay it back." So I begged my father-in-law to lend me money.

But my father-in-law wouldn't lend me money! If he doesn't have any money and refuses to lend it to me, I won't blame him, but he is obviously rich, and his savings and pension are in the tens of millions! He just needs to lend me a little bit and he can help me out.

But he didn't lend me a penny, he wanted to see me die! Do you know how vicious those loan sharks are? Those people can't get the money, they will really kill me! I don't want to die, and I don't want to have my hands and feet cut off!

So I had no choice but to kill him so that I could get his inheritance to pay off the loan sharks. In addition, I also bought an insurance policy for my father-in-law, and the beneficiary is my wife, and if my father-in-law dies unexpectedly, I can still make a profit!

So I planned today's game, and I knew that my father-in-law liked to climb mountains, so I bought a new pair of shoes and gave them to him, and then said how about trying the shoes, and asked him to climb the mountain. Then they led him to the cliff and pushed him down.

Next, as you said, I cleaned up the traces of the scene, put on another pair of shoes prepared in advance, and forged the footprints by reversing to make the police think that my father-in-law had fallen down the mountain. ”

He Jiahui nodded slightly, and then said: "But you didn't expect that the footprints you forged had loopholes, and it was impossible for you to fall down the mountain to be complete footprints."

When I raised this suspicion, you hurriedly said that Principal Xu committed suicide because he missed his deceased wife, in order to guide the direction of the police investigation. ”

"Yes, I said that my father-in-law committed suicide by missing my mother-in-law, but you doubt me more, right? You've seen my father-in-law before, and you've talked to him, but I've overlooked that, and I'm self-defeating!

Zhang Dongsheng showed an annoyed expression and sighed: "I deserve to be unlucky, I actually chose to do it today, and I actually met you student policemen!" ”

"This has nothing to do with luck, Skynet is magnificent and negligent, you break the law, you should be punished by the law! Even if you don't meet me, the police will find out about your crime and bring you to justice. He Jiahui said coldly.

This made Miao Zhishun next to him blush, he really planned to treat this case as a misstep and a cliff just now, if it wasn't for He Jiahui, I'm afraid he would have let go of the real murderer.

In order to demonstrate embarrassment, Miao Zhishun took out the handcuffs and stepped forward to handcuff Zhang Dongsheng's hands, ready to take him away.

Zhang Dongsheng didn't move his footsteps, but asked, "Can you tell me, how did you suspect me?" Even if it's for me to die! ”

He Jiahui hesitated for a moment, but finally explained: "At first, I didn't suspect anyone, and it wasn't until I saw the footprints on the cliff that I began to suspect that it was a homicide.

Footprints can analyze a lot of information, such as stride characteristics, footwork characteristics, etc., and through stride length, footwork and footprint size, you can analyze a series of characteristics such as height, fatness, gender, age, etc.

For example, the physiological differences between men and women can be presented from the footprints, under normal circumstances, the male steps are larger, the indentation is heavier, and the footprints have more digging marks and throwing soil.

Women have smaller steps, smooth ups and downs, more even indentations, and neater edges of footprints. In addition, in terms of the length of the footprints, men are generally longer than women.

In terms of age, the indentation of the forefoot in the footprints of young people in their twenties will be heavier, the indentation of the hind heel will be lighter, the digging marks on the front toe will be large, and the abrasion marks on the hind heel will be less.

By the age of 30, the indentations in all parts of the footprints will be more even, and abrasions will begin to appear. By the age of fifty, the footsteps begin to widen, the outward angle of the step increases, and the indentation of the heel becomes heavier.

There is also height, a tall person, his center of gravity must be higher, the lower limbs will be longer, when walking, the foot is long, the movement is loose, and the body sways from side to side is large, which will cause the heel to be biased, and there is a void on the outside of the toe.

Short people have a low center of gravity, short lower limbs, short feet when walking, compact walks, and are accustomed to taking big steps, and the swing amplitude will be relatively large when walking, so that the forefoot of the footprints will have digging marks.

I estimated the height of the deceased to be about 1.70 meters, and the footprints you left at the scene did not match the footprints of a man in his sixties who was about 1.70 meters tall, so I began to suspect that these footprints were forged! ”

The cadet police officers next to them were already stunned, they never thought that a footprint could analyze so much information.

Forensic Gao An even felt that if every policeman was like this, his job would be ruined.

Miao Zhishun even leaned next to Li Wensheng and muttered in a low voice, "Do you all teach such in-depth courses in your police academy now?" Thanks to the fact that I went to the police academy more than ten years ago, I would not have been able to complete my studies! ”

"How can the police academy teach such strange things! Besides, these can't be used as evidence in court! Li Wensheng responded with a cold snort.

He Jiahui ignored the muttering of others, and he continued: "Although these footprint analysis theories I just mentioned are also based on science and can only be used as the direction of solving the case, they cannot be used as substantive evidence to accuse suspects.

After all, everyone's walking habits are different, in case a big person has short legs, or a leg injury, or arthritis, it will affect the footprints. So I only suspected the cause of the deceased's death at the time, and there was no actual evidence to confirm it.

It wasn't until later, when I followed Gao Sir of the Forensic Science Department to the cliff and saw all the footprints, especially when I saw a pair of complete footprints closest to the cliff, that I was sure that the deceased did not fall by mistake, and it was most likely that he killed him.

It was also at that time that I thought about the murderer's modus operandi, but I still had no evidence, and I kept thinking about how to find it. And when I came down from the cliff and saw Mr. Zhang, I knew that the evidence was there! ”

Zhang Dongsheng's eyes revealed a trace of doubt, and he asked, "There are several people here, why do you doubt me?" How do you know that those shoes are in my hiking bag? ”

Zhang Dongsheng's words also asked the doubts of everyone at the scene.

"You are the last person to see the deceased, if the deceased was killed, you are the most suspicious, of course I suspect you first."

He Jiahui pointed to the mountaineering bag again and replied: "The reason why I guessed that the shoes were in this bag is because you have been carrying this mountaineering bag since I saw you."

It takes a lot of physical effort to climb here from the bottom of the mountain, and even those of us who have been professionally trained recruit police officers will unload our backpacks when we arrive at our destination, reduce some weight, and allow our bodies to rest.

The physical fitness of ordinary people is definitely not as good as that of us student policemen, who can walk here, they must consume a lot of physical energy, and if they have the opportunity to rest, they will inevitably unload their backpacks and will not continue to carry them on their backs.

You can look at these companions who came with you to climb the mountain, they have already taken off their backpacks, but you have been carrying the backpack on your back, don't you feel heavy?

The possibility I can think of is that you have something important in your bag that makes you afraid to take it off easily, so you'd rather bear the weight of your bag and carry it on your back.

Except for the police, who are cadet police, they are all disciplined forces, and no one will steal from you. So the question is, what exactly is in your bag that makes you so cautious that even the police can't trust it?

The answer is the pair of sneakers you used to fake the scene! ”

"I see, I thought my plan was seamless, but I didn't expect it to be full of loopholes in your eyes!" Zhang Dongsheng let out a long sigh.

"No crime in this world is seamless, as long as you do it, it will definitely leave loopholes!" He Jiahui said.

Miao Zhishun next to him waved his hand and said to his subordinates: "Take people away!" ”

Seeing Zhang Dongsheng being taken away by the serious crime team, Qiu Junxuan came over again and asked, "Jiahui, I still have a question, if Zhang Dongsheng didn't put those shoes in his bag, but found a place to throw them away, or burned them directly, wouldn't we have no evidence to arrest him again?" ”

"Those shoes are the most direct evidence of Zhang Dongsheng's crime, if it were you, would you throw such important evidence everywhere? In case someone else picks it up, then it will expose the fact that he faked the scene, and it is not difficult to speculate that he killed Principal Xu at that time. ”

He Jiahui paused, and then said: "Many murderers will not leave the murder weapon at the scene, but will take the murder weapon away, the principle is the same.

Those shoes are direct evidence that can convict Zhang Dongsheng, and they are more harmful to him than the murder weapon, and there is nothing safer than carrying them with you.

As for burning the shoes, he would definitely do it, just not here. Sneakers contain petrochemical components, and when burned, they not only produce thick smoke, but also have a strong smell.

If someone sees the smoke or smells and thinks it's a forest fire and comes to check it, isn't Zhang Dongsheng at risk of exposure?

So Zhang Dongsheng didn't dare to risk burning the sneakers here, so he could only bring the shoes with him. I guess according to his plan, it should be to take the shoes away and destroy them in private, so as not to attract attention. ”

"Makes sense, I've learned again." Qiu Junxuan nodded suddenly in realization, and at this time he had already thrown himself to the ground for the five bodies that He Jiahui admired.

Ho Ka Fai did not continue the topic, he could think of a more clever way to hide the sneakers.

For example, come to the point in advance, dig a pit nearby, and after faking the scene, bury the shoes directly in the pit, so that it becomes difficult for the police to find the shoes. Wait until the wind has passed, and then come back and take away the shoes and destroy them.

It's just that Zhang Dongsheng didn't think of this method.

Miao Zhishun, the senior inspector of the serious crime team next to him, also looked at He Jiahui with admiration, and he said to Li Sir: "Ah Sheng, the ability to learn police officers now is much stronger than when we went to the police academy, and we can solve the case before we leave the police academy."

I heard that a few days ago, there was a murder case in your police academy, and the one who solved the case was also a student policeman, and today's case was solved by a student policeman. ”

"Chief Miao, although our batch of cadet police officers are all excellent, he is the only one who can solve the case." Li Wensheng pointed at He Jiahui, and then said: "His name is He Jiahui, and he also solved the murder case of the last police academy!" ”

"Oh?" Miao Zhishun looked He Jiahui up and down, and then said with a smile: "Your name is He Jiahui, I remember you." In the future, you will behave well as a policeman, and I will transfer you to our serious crime team if I have the opportunity! ”

"Thank you, Chief Miao!" He Jiahui hurriedly thanked him.

All the student police officers cast envious glances.

The Xiangjiang police have uniformed police and plainclothes police, and the most uniformed police are the patrol officers on the streets, in addition to mobile units, stormtroopers, airport special police, flying tigers, etc.

The plainclothes police mainly include the Serious Crime Unit, O-Kee, Narcotics Bureau, CIB, Commercial Crime Bureau, etc.

Due to the division of labor, plainclothes police officers generally have more power than uniformed police officers under the same police rank, and in terms of the speed of promotion, plainclothes police officers are also promoted faster than uniformed police.

Because uniformed police often directly carry out the orders issued by their superiors, they rarely have the opportunity to solve cases, while plainclothes police are the main force in solving cases, and most cases are solved by plainclothes police, and it is easier to accumulate credit.

For young policemen, being able to take off their military uniforms and enter the serious crime team is definitely a win at the starting line.