Ren Chenjie, a teaching teacher at Sanjiang Institute of Chemical Engineering, holds a doctorate. During his doctoral studies, he mainly focused on chemical engineering application technology and principles.

Looking at Ren Chenjie's personal information, many people tried to connect him with the murderer. Judging from the time of the crime, Ren Chenjie could reasonably appear in the experimental building at any time. He had too many opportunities to replace the heating plate.

Professor Mingbo often drives to work, and there is no surveillance at the parking place. Ren Chenjie has all the time to install a bomb in his car. He even said that he could hide the bomb in Mingbo's car while driving. He has too many opportunities to install the bomb.

.

Sun Yu looked at Mingyang, he wanted to know about Ren Chenjie in Mingyang's memory.

Mingyang considered for a moment and slowly shook his head, "I have an impression of him. He is Professor Mingbo's favorite student. He will come to Professor Mingbo's house to deliver things every year and festival. Professor Mingbo speaks highly of him and says he has a bright future."

"Let people keep an eye on him first?" Xia Lan asked Sun Yu for advice.

In the investigation of criminal cases, the police can suspect anyone, but every suspicion must be based on clues. Ren Chenjie has a bright future in school. If the police find him at this time, it will definitely cause trouble to his life and career.

In the following time, Meng Yuan and Ma Youran were still studying the surveillance at the entrance of the laboratory building. Wang Lan screened the former students of Mingbo with the assistance of Xiang Fei and Mingyang. Song Wa examined the samples taken from the explosion site in the laboratory department.

fragments.

Sun Yu leaned back on his chair, taking Professor Mingbo as the starting point in his mind and extending countless lines outward.

The relationship network of the teaching profession is too complicated, especially for a professor like Akihiro who is also the dean. In addition to being in contact with students, he also has many people related to research business.

The current scope is focused on students related to Mingbo. There are two main reasons. The first is the heating plate problem, and the second is the bomb.

Sun Yu vaguely felt that they had entered into a habitual thinking. Knowing that there was a problem with the heating plate, why must it be a student from Mingbo? Students who graduated from the chemical engineering major can make homemade bombs if the raw materials are sufficient, but if there are channels, they can also buy them.

Arrived.

If they are not his students, then they are members of society, who must be related to both Laboratory 206 and Mingbo.

After thinking about it, Sun Yu turned on the computer and began to query the system for other information about each victim.

At eight o'clock in the evening, everyone was still busy with the work at hand. Xia Lan looked at everyone's hungry faces and ordered a sumptuous fast food for everyone.

While everyone was eating burgers and continuing to work, Song Wa finally came back.

Walking into the door of the office, Song Wa saw the Family Bucket on the table at a glance. He walked over in three steps at a time, picked up a burger and took a big bite.

After soothing his growling stomach, Song Wa breathed a sigh of relief. At this moment, everyone was looking at him.

"The main component of the explosive has been determined, trinitrotoluene!" Song Wa said, "It is also the common TNT."

"tnt?" Xiang Fei said in surprise. As a special forces soldier, he was very familiar with explosives. "This thing is very powerful, and it is important to grasp the amount. Combined with the explosion range at the crime scene, the murderer was very precise in the amount he used.

Knows a lot about explosives!”

"Isn't TNT a very stable explosive?" Mingyang has seen many bombing cases in school. "If you want to detonate it, you need a detonator, right?"

Mingyang's words have another meaning. This kind of bomb plus a detonator may not be something that ordinary chemical engineering students can make. Their direction may be wrong.

"I have already consulted experts." Song Wa understood what Mingyang meant, "As I said in the afternoon, as long as the raw materials are sufficient, it is completely possible to make your own, and many raw materials can be extracted from common items in life.

.

Seeing that Mingyang wanted to refute, Sun Yu interrupted him, "How is the bomb remotely exploded?"

"Electric detonators, there were a lot of car fragments at the explosion site, and there were a lot of electronic components. No parts suspected to be the starting device have been found yet. They may have been blown to ashes," Song Wa said.

Sun Yu asked again: "Can you determine where the explosion point is in the car?"

"Originally we couldn't be sure." Song Wa said, "We came to monitor the family's courtyard. There was a camera facing the explosion area. We could only confirm that the explosion started from the rear of the car. As for whether it was in the trunk or in the trunk.

It’s impossible to determine what’s underneath the rear of the car.”

They also checked the surveillance of the family home to see if any suspicious persons had come into contact with Mingbo's car. They were sure that no one had come into contact with Mingbo's car in the past few days. The car should have been at the school when the bomb was installed.

The surveillance scope of the school is different from that of the family home. The focus of surveillance is the school walls. There is almost no surveillance in the internal areas except the school road.

At this time, Zhang Yao walked in. From his posture, he knew that everyone was discussing the case. Zhang Yao nodded to Sun Yu and began to report on his investigation.

Zhang Yao said: "In the family courtyard, we visited many surrounding residents and checked the surveillance at the entrance of the building. No suspicious persons were found."

The bomb was remotely controlled, and the murderer specifically chose to explode when there was no one around Mingbo. It can be seen that the murderer was nearby when it exploded.

There are no buildings around the family home, so it is impossible for the murderer to find a vantage point to observe through a telescope. Sun Yu gave two speculations. Either the murderer was on the roof of a nearby building at the time, or the murderer had access to the monitoring server and had been monitoring the situation.

Observe the condition of Mingbo's car.

Zhang Yao's words denied the first inference. He added: "No login records were found on the monitoring server, and there were no signs of being invaded. However, I found a problem. The family home uses the campus network of the University of Technology, and the surveillance cameras use

The IP address is also the campus network address, and the login password is the default password. I just tried it and logged in to the camera outside Professor Mingbo’s house alone.”

"What the hell!" Sun Yu cursed, and everyone looked at Sun Yu. Some people looked confused.

Seeing that some people didn't quite understand what Zhang Yao meant, Sun Yu helped explain it.

Logging in to a camera individually through its IP address will not generate a record on the server. The camera uses the campus network IP address. That is to say, any campus network user within the University of Technology can log in after knowing the camera's IP address.

.

This is a network security problem that occurs when monitoring in many places. The monitoring network and the user network are mixed together. The login password is the default password, and people can log in successfully casually.

Of course, Sun Yu often uses this method to log in to surveillance cameras in some communities, so he is very familiar with this process.

The murderer used the campus network. Judging from this situation, the target of the attack was once again pointed at the school.

Sun Yu thought about it and felt that there was still hope. He asked Zhang Yao, "Can the network unit at the school find the address to access this camera?"

"We are looking into it." Zhang Yao nodded, "They said there is little hope. Schools like the University of Technology started using the campus network twenty years ago. Many users' IP addresses cannot be traced back to their source, so they can only try their luck. Unless the murderer

It uses a wireless network, and you need to log in with your student ID and staff card number. In that case, you can find someone, but I feel it is unlikely."

After talking about the situation in the family home, Zhang Yao began to report on the situation in the school.

"We asked about two places where Professor Mingbo often parks. There is no surveillance. We visited the cleaning, building management, and logistics staff of nearby buildings. They found no suspicious persons approaching Professor Mingbo's car."

Zhang Yao cast a confirming look at Sun Yu, "Is it possible that the murderer did not tamper with Professor Ming's car? He is someone Professor Ming knows and put the bomb in his trunk under some pretext.

"

After an afternoon of visits, Zhang Yao's mind has begun to gravitate toward someone inside the school committing the crime, and it is someone who is familiar with Mingbo.

"It is indeed possible." Mingyang suddenly said, he sighed, "Professor Mingbo likes drinking and fishing. There are often one or two boxes of wine and a set of fishing gear in the trunk of his car. If a bomb is hidden in there,

It's not the weekend, he won't find out."

"Is it possible that it's a gift?" Sun Yu's tone was hesitant.

"It's possible." Mingyang said, "Now is the graduation season, and some of his students may give him something. And the Dragon Boat Festival has just passed, and there must be some wine in his car for him. His lover doesn't like him.

He drinks, so his wine is usually kept in the car.”

"We did find a lot of wine bottle residues and fishing gear," Song Wa added.

"Alas!" Sun Yu sighed, took out a cigarette and lit it. He regretted letting Mingyang participate. It was not that Mingyang talked too much and actively participated in case discussions, it was easy to create sparks. Sun Yu liked discussions.

.

What bothered Sun Yu was that there were some things he couldn't say clearly.

Mingyang glanced at Sun Yu thoughtfully. He came to Sun Yu, took out a cigarette from Sun Yu's cigarette case, lit the cigarette and whispered, "Brother Yu, if you have any ideas, just tell me."

, I just want to find the murderer."

Sun Yu took a long puff of cigarette and exhaled a thick white mist.

"I don't think we can walk on one leg. Putting aside other clues, there were two explosions. One was Laboratory 206, and the other was Professor Akihiro. The murderer was a revenge murderer. At the same time, he had irreconcilable conflicts with them. In addition to the disputes within the school,

,Are there any other possibilities?”

Xia Lan instantly understood what Sun Yu meant by giving gifts. She said, "These laboratories have research projects for external parties, and have interactions with many companies in society. They have business relationships. Could it be a vendetta caused by economic disputes?"

"If there were no Professor Mingbo, I agree with this possibility." Mingyang said seriously, his tone was very sincere, "Professor Mingbo hates gray income extremely. He cannot take anyone's money, so it is impossible to have any relationship with the college.

Some of the companies we cooperate with have had irreconcilable conflicts."

As he spoke, Mingyang realized that his words were highly subjective, and sighed: "You can check this. I just think it is a waste of time to check from this point."

"Then check this Zhao Peng first!" Sun Yu said, "He is also dead. Let's see if he offended anyone outside the school."

"Brother Yu." Meng Yuan looked embarrassed, "I think your guess is reasonable, but it is not reasonable with the actual situation! I understand what you mean. This may involve Mingbo or Zhao Peng abusing their power to obtain a large amount of gray income.

, and then did not do anything for the other party and was retaliated against.

But is this kind of revenge going too far? And how could those outside the school know about the heating plate? How could they make a bomb?"

Sun Yu smiled helplessly, "The reason why I suspect someone outside the school committed the crime is actually very simple. There are currently no major suspects in the school. It is normal to change the perspective."

Sun Yu was not idle these past few hours. He made a psychological evaluation by understanding the victim's situation and the personnel files of all employees of the School of Chemical Engineering. At least he did not think that these people had the possibility of committing a crime.

At this time, Zhang Yao's phone rang.

Zhang Yao answered the phone, said a few words briefly, and then told everyone: "The network center of the University of Technology has found out the results. By retrieving the IP address record of the accessed camera, it was determined that it was a student user using the campus wireless network.

, the name is Yue Xinhao."

"Yue Xinhao?" Sun Yu was stunned, "He was a victim of Laboratory 206, and he is no longer here!"

Zhang Yao pressed the speakerphone directly, and a man's voice came from the other side of the phone.

"Yue Xinhao's login password is very complicated and cannot be guessed. I think the murderer should be someone who is very familiar with him." The teacher at the network center added his own thoughts, and it seemed that he had a heart for being a detective.

"What's the most recent login time for this account?" Sun Yu asked.

The teacher replied: "I logged in once at 7:30 in the morning. Our school's students' wireless accounts support multi-terminal login. At 7:30 this is already the fourth terminal. I can determine its physical address."

A physical address is something that every device that uses the Internet will have, just like people's ID cards.
Chapter completed!