traces of all things

Tang Shaoyuan actually doesn't like speaking in public very much.

It may be the relationship he has experienced since he was a child. Being forced to be exposed to the eyes of many people will always make him a little inexplicably nervous and burdened.Usually when we are in a group, the discussion of the task force is usually a few acquaintances in the group, which is not very stressful. At other times, he listened carefully to the content of the forensic medical examination that he had come forward to explain, and occasionally asked a question or two.

When Lu Zheng had a conflict with Xue Yiwei last time, he suddenly stood up to argue with Xue Yiwei, and surprised Daxiong who was present.

He squeezed the notebook in front of him, and saw Lu Zheng smiling at him on the stage, his eyes were full of trust and encouragement, he was dizzy for a moment, and when he realized it, he was already standing in front of the stage.

...Really, the color makes the mind faint.

Tang Shaoyuan reached out to push his glasses, coughed, and opened his work notes.

He did a lot of this part of the work before, so he is naturally familiar with the content, and there is no difficulty in explaining it at this time.

"According to the inquiry of Professor Mei, the reason why he left the office was because he received a call from a student that there was a strange smell in a laboratory in Professor Mei's group. According to the description of the students at the time, it smelled like gas. smell. He got nervous and left the office."

Xue Yiwei and others in the audience nodded slightly when they heard this.

Under normal circumstances, there is an unknown odor in the laboratory, and the professor who is mainly responsible really needs to go to check it.

"Professor Mei's office structure is the same as Teacher Guan Bin's office. There is a latch on the inside of the door. The door lock uses this common spherical door lock. The brother checked Professor Mei's door lock and found no violence. Traces of damage. This kind of door lock has a characteristic, that is, if you need to lock the door when you leave, you have to screw the door lock inside first, and then go out to close the door, which is troublesome. Professor Mei also admitted that he has a bad memory, and there are indeed Forgot to lock the door when leaving several times."

Xue Yiwei raised his doubts below: "But in this case, isn't it too unsafe? How did the murderer know that Professor Mei would leave the office at that time and not lock the door?"

"The murderer just knew." Tang Shaoyuan nodded and dropped a time bomb: "Because it was he who made Professor Mei leave the office, and he tried more than once to ensure that the door of the office was not locked—in the event of a fire. In the past two weeks, Professor Mei remembered that his laboratory also had a certain odor problem. He left immediately to deal with it, but locked the door when he left. After the security department checked and found no suspicious items, he didn't take it to heart. Go. However, two weeks later, such a thing happened again, and I personally think that such intensive frequency is probably not a coincidence."

Now the people attending the meeting exploded, and everyone couldn't help whispering in an eager and excited mood. For a while, the meeting room was full of "buzzing" sounds.

"Be quiet and finish listening to Shao Yuan's report." Lu Zheng spoke in a timely manner and made a "stop" gesture.

Xue Yiwei, who started the mindless following mode for Lu Zheng, immediately raised his fingers like a small squad leader and "shh" desperately.

The discussion in the audience gradually stopped, and the room became quiet again.

Tang Shaoyuan pursed his lips, glanced at Lu Zheng, and finished the final report.

"It just so happens that the security department of Provincial Normal University is investigating the odor incident in Professor Mei's laboratory, and the physical and chemical backbones of our provincial, department, and municipal bureaus have also conducted a blockade inspection of the entire laboratory. A very small amount of ethanethiol residue was found on the side of the ground."

"What is that?" To Wei Xiongfeng, these nouns were like a bible.

Tang Shaoyuan also knew that this was not his professional field, so he did not hate him for the first time, but rather patiently explained: "Ethanthiol is a very commonly used reagent in organic synthesis laboratories. It is very volatile and has a strong smell. Once sprayed, there will be a gas smell. The first time there was a peculiar smell in the laboratory, because the dose was relatively small, it was not detected, but the second dose was relatively large, and the residue was found."

"Wait, then has their laboratory registered the use of ethanethiol reagent?" Xue Yiwei's mind turned quickly, and he immediately grasped the point.

"No." Speaking of this, Tang Shaoyuan also looked a little regretful: "Because ethanethiol is commonly used, it is basically in a state where everyone can take it in the reagent room, and there is no surveillance video inside the reagent room and laboratory. At that time Since it was noon, people were coming and going, and the place where ethanethiol was dumped was close to the door, the people in the laboratory had no impression of seeing any suspicious people or things."

Everyone's mood was raised high and then gently lowered, and everyone's faces were depressed with naked eyes.

One clue after another was discovered, and another clue was ruled out. Everyone in the task force has been tortured, and now they can continue. Except for the superhuman perseverance honed as a criminal policeman, basically they can only rely on the road. Zheng's chicken soup is perfect.

"Brothers, cheer up, we have taken a big step!" Seeing that everyone was a little depressed, Lu Zheng stood up sharply and clapped his hands: "People don't appear out of thin air. Although the experiment There is no surveillance video in the room, but in order to enter and get close to Professor Mei’s laboratory, the murderer must pass through the downstairs gate of the laboratory building during that period of time, and surveillance cameras are also installed at the corners of the stairs of the laboratory building. We recorded all of these surveillance videos Extend it again, you don’t have to worry about finding the suspect! Daxiong, you and I are responsible for leading a team to investigate the surveillance video, Yiwei and Shao Yuan, the two of you are responsible for investigating the way the murderer obtained GHB-this controlled drug is not for everyone There are all ways to get it, and starting from this angle, it can also help Nobita and the others screen out a few suspects, okay, the meeting is over!"

After the work was assigned, the small investigators found their backbone again, but they seemed less depressed. After the work was divided, Lu Zheng and Wei Xiongfeng started the long video investigation work again.

There is a surveillance camera at the entrance of the laboratory building and at the corner of the stairs on each floor. Lu Zheng and the others quickly contacted the security department of Provincial Normal University A to obtain all the surveillance camera videos. According to the abnormal smell found in the laboratory The time was advanced by three and 10 minutes before and after, and intercepted.

"This building has six floors, of which Professor Mei's laboratory is on the fifth floor, and there is a fire-fighting staircase on the other side. There is no surveillance camera on the stairs." Wei Xiongfeng scratched his hair vigorously, his face Lu collapsed: "Ahhh! Why can't you install a few more!"

"I'm going, it's going to snow." Lu Zheng turned his head away and shook his hands: "Daxiong, you are scratching, the sky is full of dandruff, haven't you washed your hair for a few days?"

Wei Xiongfeng looked aggrieved: "Team leader, I wash every day! Are you infected by Tang Shaoyuan? Let me tell you, stay away from him, otherwise you will have nowhere if you get infected with his hypocritical disease." Erzhi."

Before the words fell, a book was hit on his head: "Speak ill of people behind their backs, you should be beaten."

"Team leader! You are eccentric!" Wei Xiongfeng was heartbroken: "I don't believe that Tang Shaoyuan never said anything about me behind my back."

"That's different." Lu Zheng double-labeled quite candidly: "He was bluntly admonishing you, pointing out your shortcomings frankly."

Wei Xiongfeng: ...I can't live through this day.

**

No matter how hard life is, the investigation must continue. With a whole team of small investigators, Lu Zheng and Wei Xiongfeng started to review the surveillance videos of all gates and stairs.

During this period of time, it was the time when the students and teachers finished their meals, and people were coming and going, which made people dazzled.

"This is Zhou Xuehai, and Wang Yong is walking with him." Wei Xiongfeng pointed to the two people in the middle of the screen and said. It looks good.

"This Zhou Xuehai has a good relationship with everyone." Lu Zheng nodded thoughtfully: "When he came for an interview, he obviously looked down on Wang Yong."

"Hmph, it's not uncommon to see this kind of person." Wei Xiongfeng snorted, as if pointing something: "Duplicate, in front of people, flattering, and when behind people, they act like everyone It doesn't look good anymore."

Lu Zheng ignored him and continued to concentrate on watching the surveillance video at the door.

After a while, another unexpected person appeared at the door.

"Xiong Boyi? Didn't he graduate? What are you doing in the lab?" Lu Zheng muttered to himself, frowning slightly.

Xiong Boyi appeared in Guan Bin's office before. According to him, it is understandable that some formalities for graduation have not been completed, but it is really unreasonable to come to the laboratory building after graduation.

I saw Xiong Boyi's chubby figure appearing at the door of the laboratory building, walked in hastily, and disappeared into the range of the monitoring probe.

Resisting the urge to immediately open the next video, Lu Zheng continued to sit still and watch the surveillance.A few minutes after Xiong Boyi left, an extremely familiar figure appeared on the screen.

"My God." Wei Xiongfeng almost lost his eyes in shock: "Isn't this Tang Shaoyuan?"

"He went to the canteen on the first floor of the laboratory building to buy mineral water." Lu Zheng explained: "The two of us were playing on the basketball court of the Provincial Normal University that day."

Only now did Wei Xiongfeng remember the basketball game, and couldn't help but look at his short legs with envy and hatred.

Tang Shaoyuan came out shortly after he went in, looking a little flustered as he walked hurriedly.

"Hey, if it wasn't for Tang Shaoyuan, I would have doubted him." Wei Xiongfeng complained, "Looking at this little flustered appearance, it's very suspicious."

Lu Zheng smiled, originally wanted to rub Wei Xiongfeng's head, but thought of the floating dandruff and silently put down his hand: "It is reasonable to doubt that killing relatives with righteousness is worthy of recognition. However, Tang Shaoyuan did not stay in it for more than 3 minutes , is not enough to complete a series of actions of running up to the fifth floor, pouring ethanethiol, and running down the fifth floor."

"Are you kidding me?" Wei Xiongfeng scratched his head: "...Hey! This Xiong Boyi came out!"

On the screen, there is a short girl next to Xiong Boyi, and the two walked out talking and laughing.

"This little girl should be Jin Yi who has a good relationship with him." Lu Zheng clicked on the video and said, "Check with the two of them then."

Before the words fell, Wang Yong also walked out ghostly.

"Huh? Why are these people going out?" Wei Xiongfeng frowned slightly, and then immediately let go: "Hey! This is Zhou Xuehai, he also came out!"

After Wang Yong walked out of the gate of the laboratory building for a while, Zhou Xuehai also walked past the surveillance video at the gate.

Lu Zheng frowned slightly: "There is only one entrance and exit, wait for the video of each staircase..."

Before he finished speaking, he suddenly stopped.

An unexpected person appeared in the picture.

Low ponytail, dress, thin figure, trance-like steps.

——It was Shi Jingyi who should have left the school directly after leaving Guan Bin's office.