Zhou Ning followed Xu Dayuan and ran towards a building behind the office building. They came to a room on the third floor and the door was already open.
The room was filled with various test instruments. It was obviously a laboratory. Seeing several familiar criminal police officers squatting in a corner, Zhou Ning hurried forward. Zhou Xiaoyu was lying on the ground unconscious, with tape on his mouth and white cable ties on his hands and feet.
Zhou Ning quickly squatted down, cut the cable tie, raised his hand to test Zhou Xiaoyu's carotid artery, and found that her heartbeat was normal. As his fingers passed over her hair, a blow wound on the back of her head was revealed. It was only a crescent-shaped skin injury, and such an injury would not cause her to fall into a coma.
Zhou Ning's heart was in his throat and his eyes felt a little sore.
Zhou Ning quickly hugged the person in his arms and gently patted Zhou Xiaoyu's cheek, calling out.
"Xiaoyu, Xiaoyu wake up!"
Zhou Xiaoyu slowly opened her eyes. Seeing her open her eyes, Zhou Ning finally felt relieved.
"Brother, why are you here? Why am I here?"
"Do you remember what happened?"
Zhou Xiaoyu held her head and sat up, still seeming a little dizzy.
"I don't know. Wait... Cui Guanglin hit me with a water cup, and when I fell, he rushed over and covered my mouth. Then I don't remember anything."
Zhou Ning checked Zhou Xiaoyu's neck again, pressed around the wound, confirmed that the wound was not serious, and there were no fingerprints on her neck. Seeing that her lipstick was rubbed off, he quickly used a cotton swab to extract Zhou Xiaoyu's lips and nasal cavity, put the cotton swab away, and then comforted her:
"Okay, everything is over. Now recall, what time and where did you meet Cui Guanglin today?"
Zhou Xiaoyu rubbed her wrists. Some of the marks from the bruises had already broken. She gasped in pain.
"As soon as I arrived at school in the morning, I saw Cui Guanglin in the corridor of the office building. He waved at me. I put my bag back in the office and thought you were right. There were some things I needed to make clear, so I left the office and saw him at the corner of the corridor.
He said that no matter whether we continue to prepare for marriage or break up, we should at least make it clear. There are too many people here, so we should go to the laboratory where it is quiet. I followed him to the laboratory on the third floor of the science and technology building.
But as soon as the door opened, he hit me on the back of my head, and then he covered my mouth and nose. I was very panicked at the time, and I didn't know what Cui Guanglin was going to do. I struggled for a few times , but I had no strength in my body, and then I knew nothing. What happened to me?"
Zhou Ning hugged the still trembling Zhou Xiaoyu, feeling a little scared. He patted her on the back and said soothingly:
"Don't be afraid, I'm here. Be good and go to the hospital with my colleagues for a checkup. As for Cui Guanglin, he has been caught by us. As for his case, I will tell you after the investigation is finished here. Da Zhao, please help me find someone to take Xiaoyu to the hospital!"
Da Zhao came over and helped Zhou Xiaoyu up.
"Don't worry, I'll ask Sister Feng to take Xiaoyu to the hospital, and you can call Director He."
Zhou Xiaoyu held Zhou Ning's hand, looking a little anxious.
"Don't tell my mom!"
"Don't worry, I won't tell them. If I tell them, it will just make them worry. But you have to listen to me and check it out carefully."
Zhou Xiaoyu nodded and followed Da Zhao downstairs. Zhou Ning glanced at the place where Zhou Xiaoyu had just sat on the ground. Under a table next to it was a cabinet with all the doors open. There were traces of scratches and trampling inside. Zhou Ning narrowed his eyes.
"Xiaoyu was stuffed into this cabinet?"
Xu Dayuan patted Zhou Ning on the shoulder. He could feel Zhou Ning's anger. If it were him, he would probably not be able to control his emotions.
"Not only was Xiaoyu stuffed inside, but she was also locked. The lab has already been searched once. During the second search, all the cabinets were opened to check, and only then was Xiaoyu found. Fortunately, she is fine."
Zhou Ning nodded. This was the key sentence. Fortunately, no one was hurt. If Xiaoyu was hurt, Zhou Ning didn't know how to blame himself.
"I should have let Xiaoyu rest for a few days last night. It was all my carelessness."
"Don't come on, don't be sad with me. So many teachers are in the multi-purpose hall. I'll go deal with it first. Take Cui Guanglin away. You check here and go back to the team. Da Zhao stays to help. I don't understand why Cui Guanglin controlled Xiao Yu."
Zhou Ning shook his head. He couldn't understand this. If Cui Guanglin was really the murderer of the March 10 case, he might also be the murderer of the Red Dress Serial Murder Case. Such a person had severe obsessive-compulsive disorder and was so rigorous. The only thing he missed was the person who was fishing. But what happened today?
Is it because of the Zhou family’s reaction?
Or, if you can't get it, you have to destroy it. Thinking of this, Zhou Ning became even more scared and took a deep breath to control his emotions.
"Xu Da, go ahead and do your work. I'll ask Xiao Qu to check the surveillance cameras in the building. As for here, it's not difficult for a chemistry teacher to make some chemicals that can cause people to temporarily become unconscious."
Xu Dayuan waved his hand and led his men away, and Da Zhao ran back quickly.
"Sister Feng took Xiaoyu to the hospital. She followed the 120 ambulance. Did you call?"
Zhou Ning took out his cell phone and called He Shancun.
"He Shancun, I am Zhou Ning."
"Speak of things, I'm busy!"
"My sister Zhou Xiaoyu was sent to your hospital by 120. She will be here soon. She was hit on the back of her head. Please check if she has any fractures or concussion. I also suspect she was knocked unconscious. I collected samples from her nasal cavity and the edges of her lips, but I don't know if there are any residues. Please help me check Xiaoyu carefully.
According to Xiaoyu, she was knocked unconscious before eight o'clock and was just woken up by me. If it wasn't an anesthetic, what chemical could cause such a long coma?"
He Shancun paused, obviously shocked by Zhou Ning's words.
"What? Your future brother-in-law did it? I remember you said last night that he taught chemistry, right?"
"Well, give me a direction. I'm in the chemistry lab at their school."
“Don’t worry, as inhalation anesthetics, we commonly use sevoflurane and desflurane, but there are many similar ones such as halothane, enflurane, and isoflurane that can also be used as anesthetics.
I remember reading in a magazine that as long as you can use hexafluoroisopropanol and dimethoxymethane to react in the presence of a catalyst and then add some strong acid or something, you can get sevoflurane. As long as you are an expert in chemistry, these are not difficult things.
But this thing is a gas, which is difficult to store, while fluorocarbon is a liquid with a fragrant smell, but it is not stable. "
Zhou Ning was a little confused, but he remembered these names .
"I see. I found these chemicals. If there are Cui Guanglin's fingerprints on them, then it will be fine."
"Well, that's about it. Oh, and look in the trash can. If he has used it, at least there are bottles and gauze around. These things will metabolize into hydrohalic acid when exposed to light or heat, and we can test it."
"Thank you. I'll leave Xiaoyu to you."
After hanging up the phone, Zhou Ning looked at Da Zhao.
"Let's start looking. Cui Guanglin's fingerprints have been collected. We need to look for the bottles and gauze in the trash can. We need to find fluorocarbon, hexafluoroisopropanol and dimethoxymethane here."
Da Zhao nodded.
"Don't worry, I heard it and found out what the words are. Let's get started!"
As he spoke, he began to search on all the test benches. Zhou Ning took a look and went straight to the trash can at the door. When he opened it, he saw a piece of gauze and a brown glass bottle on the top. He picked up the two things directly.
Zhou Ning collected fingerprints on the brown bottle and found without comparison that there was a mark on the edge of the fingerprint, which was obviously left by the Band-Aid.
"Da Zhao, I found it!"
Da Zhao came over and put the cable tie into the evidence bag.
"It seems that this person was in a hurry and didn't have time to deal with these things."
Zhou Ning nodded, put all the evidence bags into the investigation box, and stood up.
"The first class is at 8 o'clock. Cui Guanglin brought Xiaoyu here and knocked her out and stuffed her into the cabinet. We have wasted too much time. Let's go check on Xiaoqu to see if there is anything new."
The two went downstairs and drove towards the guardhouse. It was lunch time and many students were looking at them. The police car was still too conspicuous in the school.
I arrived at the guard's room and saw Xiaoqu waving as soon as I entered.
"This Cui Guanglin seems to be very familiar with the surveillance cameras on campus. He avoided the surveillance cameras during get out of class. Even when he couldn't avoid them, he hid among the students. I found a few pictures. Look at 8:45. He went out from the side door and followed a few students.
Then at 8:59, he entered the staff dormitory building, but there was no surveillance here. The guard who was on duty just now said that the surveillance on their faculty and staff floors had been broken for a long time, and he didn’t know where he was between 8:59 and 11:50.
What can Cui Guanglin do during the three-hour window?
"Let's go to the dormitory building. Master has already gone there."