Chapter 556: Complete Chain of Evidence

Hardware factory.

Sandblasting machine.

High temperature furnace.

Several keywords that do exist, but at the beginning of the case, no one immediately linked them to the body, including Chen Yi.

Anyone who has killed someone knows that the most troublesome thing is to deal with the body.

For such a big person, it takes a lot of effort to make him disappear completely from the world. It is almost impossible, and the only way is to hide him to the greatest extent.

Even if the body is dismembered, there will always be traces left.

Bones, flesh, hair, teeth...

How to hide?

Acid dissolution and fire burning are both good methods as long as the conditions are met.

And the sandblasting machine can do it more thoroughly.

The working principle of the sandblasting machine is to accelerate the abrasive to the surface of the workpiece through compressed air to complete the carving action, thereby achieving the physical effect of cleaning and strengthening the surface.

The spray material is composed of sand and gravel such as corundum, copper sand, and iron sand, and it is very hard.

Imagine what will happen if countless hard gravel hits the flesh and bones at high speed.

This is much simpler than dismembering the body, and it becomes a scum in the true sense of the word.

However, the use of sandblasting machines is limited. The work needs to be carried out in a completely sealed iron box, or wearing professional protective clothing outdoors. If it is used openly indoors, the user's eyes and lungs will be fatally injured.

There are few professionals, and the crime rate will be very low on average, so no suspect has been heard of using sandblasting machines to deal with corpses.

Now, there should be one.

Sandblasting machines are combined with high-temperature furnaces. Under the premise of unknown, no one can think of finding clues.

However, it is impossible for sandblasting machines to deal with corpses to achieve the effect of turning to ashes. A large amount of DNA will be left around, which are all evidence.

"Let go!!" Kou Chaoyi was in pain and sweated coldly. He went to see the police officer in charge of recording and found that the other party lowered his head and ignored it, and had no intention of recording.

"Chen Yi, I want to sue you!"

Chen Yi: "Answer my question."

Kou Chaoyi said angrily: "I don't know!"

Chen Yi waved his left hand to the observation room. When He Xin saw this, he immediately took people away and notified the technical investigation to go to the hardware factory immediately.

The hardware factory has now been sealed for suspected manufacturing of gun parts, and it will usher in a comprehensive investigation of the second case.

In the interrogation room, Chen Yi did not waste time with Kou Chaoyi and left.

Kou Chaoyi was very stubborn and needed to wait for two things.

The first thing was the investigation results of the hardware factory.

As long as the victim's DNA was found in the hardware factory and the chain of evidence was closed, even if Kou Chaoyi did not have a confession, it could be submitted to the procuratorate for review and prosecution.

The second thing was Guan Xinmei's psychological evaluation and treatment results.

If Guan Xinmei could tell the truth, it would be of great help to the police in interrogating Kou Chaoyi.

One is human evidence and the other is physical evidence.

It would be best if both were available.

Back in the office, Chen Yi called the psychologist, but no one answered.

He called Jiang Xiaoxin again and she answered.

Now Jiang Xiaoxin is mainly responsible for Guan Xinmei's affairs. The two had a good chat. Relatively speaking, Guan Xinmei trusts Jiang Xiaoxin more, but still did not provide any useful information for the case.

"Captain Chen."

Chen Yi: "What's going on?"

Jiang Xiaoxin was very quiet. She lowered her voice and said, "I'm waiting outside. Guan Xinmei fell asleep. Professor Liu hypnotized her.

From what Professor Liu said, Guan Xinmei doesn't seem to have Stockholm syndrome, but there must be psychological problems. I guess it may be post-traumatic stress disorder. She refused to answer any questions about Kou Chaoyi because she was afraid."

Chen Yi: "Is it serious?"

Jiang Xiaoxin: "Professor Liu suspects it is a delayed type, which is more serious."

Post-traumatic stress disorder can be divided into acute, chronic and delayed types according to the severity of the disease. When it comes to the delayed type, it will be very difficult to treat.

Chen Yi: "Okay, I know. Tell me as soon as you have news. Remember to record it."

Jiang Xiaoxin: "Understood."

After hanging up the phone, Chen Yi pondered.

The typical symptoms of post-traumatic stress disorder are trauma re-experience, increased alertness, avoidance, numbness, sleep disorders and depression. Judging from Guan Xinmei's condition, avoidance and numbness are more consistent.

She said she didn't know anything about Kou Chaoyi. This is avoidance.

On the surface, she is indifferent and dull, but in fact, she is alert inside and has lost interest in most things. This is numbness.

As for the others, I haven't seen it yet.

Psychologists are more professional in this area. It seems that they have assessed that Guan Xinmei has a certain degree of depression.

There is no need for thorough treatment in a short period of time. As long as it is effective and can make Guan Xinmei tell the truth, it will be fine. The treatment of severe post-traumatic stress disorder is a long-term process.

Kou Chaoyi, I am afraid he has done a lot of bad things to Guan Xinmei.

…

Sun Menglan's mother arrived, and the forensic doctor extracted her DNA and sent it to the laboratory for DNA paternity testing, confirming that the bloodstains found in Guan Xinmei's dormitory came from Sun Menglan.

Sun Menglan is also in danger.

The police will certainly not tell Sun Menglan's mother about the speculation of the case. The hardware factory has not found Sun Menglan's DNA yet. If it has not been found, it cannot be said that the person is dead.

However, Sun Menglan's mother does not seem to care much about her daughter. After learning that Sun Menglan could not be found, she just asked the Municipal Bureau to notify her after finding her, and then she will leave.

Because there is still a young son at home who needs to be taken care of.

The police officer who received Sun Menglan's mother was a little angry. After all, she was her own daughter, and this was too careless.

Other people's family affairs, can't be controlled, can only be morally condemned.

Otherwise, Sun Menglan would not have been missing for several years without anyone paying attention. If the police hadn't taken the initiative to find her, it might have remained a mystery forever.

Poor.

Sad.

The search for Xu Chaoyue's mother and son did not stop. The local police station knew that this was a case of the Municipal Bureau and it was of great importance. They tried their best to find all the relatives they could find, but no one knew where the mother and son had gone.

During this period, the forensic doctor extracted Xu Chaoyue's relatives for DNA kinship identification. The result was the same as everyone thought. The last unknown bloodstain in Kou Chaoyi's office should have come from Xu Chaoyue's mother.

They are all relatives, why not Xu Chaoyue? Because the bloodstain came from a woman.

Since then, the owner of the bloodstain has been confirmed.

The bloodstain in Guan Xinmei's dormitory came from Sun Menglan, the former president of the Student Union.

The bloodstains in Kou Chaoyi's office came from Fu Peilan, Xu Chaoyue's mother, and Du Xun.

They are all missing, which means they are all dead.

As for Xu Chaoyue, we don't know what happened yet, and his bloodstains have not been found anywhere.

When Xu Chaoyue disappeared, the first reaction of normal parents would definitely be to come to the school to look for him, come to the school to ask, and if there is no result, they will immediately call the police. This may be the reason for the death of Xu Chaoyue's mother.

I killed your son, and you want to call the police if you can't find him, then I can only kill you again.

Both mother and son were killed, and there were no other direct relatives. No one cared that two unrelated people suddenly disappeared in the world.

Chen Yi went to the hardware factory to supervise in person, and almost all forensic doctors and technical detectives came. Not only the sandblasting machine operation room, but also the entire hardware factory had to be carpet-searched.

The amount of work is not small.

The case has been reported to the provincial department. Wei Jianfeng and the deputy department in charge attached great importance to it. In order to cooperate with the criminal investigation detachment of the municipal bureau to speed up the investigation, a trace inspection team headed by Cheng Hanjun was sent to shorten the investigation time.

At this moment, Chen Yi was talking on the phone with Wei Jianfeng.

"Four people's bloodstains, five people are missing, are they all dead?" Wei Jianfeng said on the phone.

Chen Yi: "I can't guarantee whether Xu Chaoyue is dead or not, but the other four people are in danger. If DNA from Xu Chaoyue is found in the hardware factory, then it can be said that all five people are dead."

Wei Jianfeng: "Does the suspect have a motive to kill Xu Chaoyue?"

Chen Yi: "Yes, not only does he have it, but he is the most complete among the five."

The key to the case is Guan Xinmei. As Guan Xinmei's boyfriend, Kou Chaoyi must want to kill him the most.

Wei Jianfeng sighed: "The result is about to come out, let's close the case as soon as possible. This matter has a huge impact, and confidentiality must be done well.

Also, try to appease Guan Xinmei and don't let her go out and talk nonsense. This is also what the higher-ups mean."

It seems that the provincial department is not prepared for an open trial.

It is understandable that once the case is made public, it will be enough to cause a huge earthquake across the country.

This is not a question of how many victims there are, but the nature.

By then, all private schools will be affected.

Chen Yi obeyed the order: "Okay, I know."

Not making it public now does not mean that it will not be made public in the future. Maybe after a while, everyone will know it.

The recent cases and the cases in previous years sound different.

The official announcement of the major homicide that happened many years ago was just for fun and became a topic of conversation after dinner. However, if the major homicide that happened yesterday was announced, public opinion would burst out like a fountain and cause panic.

The phone was hung up.

…

The investigation lasted for two days and two nights. The city bureau laboratory was almost smoking. In the middle, the provincial department laboratory also joined the test, and even the branch with testing capabilities was also requisitioned.

Finally, the results came out.

In the operating room of the hardware factory, everyone's DNA was found.

Everyone means, including Xu Chaoyue.

There was no luck, no accident, the fact is that everyone is dead.

Before the interrogation, there was progress on Professor Liu's side.

Guan Xinmei spoke.

According to Jiang Xiaoxin's description, she just lay there quietly, tears streaming down her face, crying very sadly, and described Kou Chaoyi's actions in detail.

Indecent assault is a minor matter.

Kou Chaoyi has violated Guan Xinmei countless times in that independent dormitory over the years.

The first person killed was Sun Menglan.

Sun Menglan was resentful and jealous because of Kou Chaoyi's special care for Guan Xinmei, so she went to Guan Xinmei to settle accounts. When she was beating, Kou Chaoyi arrived and ended Sun Menglan's life.

The hammer used.

This move was to "help" Guan Xinmei get revenge and to deter her.

I can kill her, and I can kill you, so just be obedient.

Guan Xinmei didn't know anything else. She didn't even know whether Fu Peilan was dead or alive. She suspected that her mother was dead, but she didn't dare to ask Kou Chaoyi.

Kou Chaoyi had completely controlled Guan Xinmei in all aspects of spirit and body.