The whereabouts of the suspect after entering the teaching and research building was basically found out.

However, the monitoring outside the teaching and research building can only be kept for half a month, and the whereabouts of the suspect outside the teaching and research building cannot be found through monitoring.

The biggest problem in stealing corpses is how to transport them out.

Transporting the teaching and research building from the storage room is one stage, and transporting it out of the school from the teaching and research building is another stage.

Moreover, this case is not just about theft.

It is impossible for the female teacher named Da Ti to appear out of thin air. It should have been transported to the school from outside, and placed in a formalin pool for a period of time, and then moved away after the corpse was embalmed.

This behavior is somewhat intriguing, what is the ultimate purpose of the suspect?

If it is purely for anti-corrosion purposes, just find a hidden place, why bother to transport it into the school?

How did the suspect transport the corpse into the school, and then transport the corpse away?

Han Bin felt that the suspect was either brave enough or he was in the school.

"Director Ma, are there many people on campus in July?"

Ma Tao thought for a while, "Huh, I'm really not sure about this. The situation in various departments is also more complicated."

"Director Ma, you should have noticed that this case is not a simple theft case. It may be more complicated than we thought. I want to have a more comprehensive understanding of the school and would like to meet the senior leaders of your school."

Ma Tao gave a wry smile, "I can't be the master in this situation, I need to report to the school leader."

"It should." Han Bin took out a business card, "There is my phone number on it, so you can contact me directly."

"Okay." Ma Tao took the business card, greeted everyone, and then left the monitoring room.

After that, Han Bin also left the monitoring room and took Guo Tianxu and Bao Xing back to the back door of the teaching and research building. Li Qin and Yanzi stayed in the monitoring room and continued to check the video to see if they could find more clues.

Han Bin returned to the back door of the teaching and research office, first to see if the suspect left a clue, and second, to check the suspect's route in and out of the school.

Han Bin set off from the entrance of the teaching and research building and went around the school, but found no obvious traces.

In fact, it's normal to think about it, more than a month has passed, even if there are clues, it is almost destroyed.

"Captain Han, you are here, I finally found you." Wang Jinliang, deputy director of the Academic Affairs Office, walked over, panting, and was followed by a woman in her forties.

"Let me introduce you, this is Director Sun Yuefen of the General Affairs Office."

Sun Yuefen took the initiative to say hello, "Captain Han, hello."

Han Bin said politely, "Director Sun, please take a special trip."

Sun Yuefen spoke very freely, "It should be for the school's affairs. Just say what you have."

"Do you have a backup of the key to storage room No. 207 on the second floor of the teaching and research building?"

"Yes, we have a backup copy of the keys to most rooms in the school."

"Where are the keys stored?"

"The General Affairs Office has an office dedicated to storing keys and documents. The doors of the office are generally locked and the storage measures are very strict."

"Is the key to room 207 still there?"

Sun Yuefen took out four keys worn in one from his pocket, "Yes, I heard Chief Wang said, so I brought the keys by the way. There are four keys in total, even Director Ma's one, exactly five. "

Han Bin handed the key to Bao Xing, "You go and see if it can be used."

Bao Xing took the key and ran away.

Han Bin asked, "Director Sun, will your general affairs office be on duty during the vacation?"

"Yes, the general affairs office is in charge of a lot of things, no one can't do it. Usually one or two people are on duty."

Han Bin nodded. As Ma Tao said earlier, there are many departments in the school, and each department has a different division of labor. Most of them have employees left behind, which is not good for statistics.

"Dingling bell..." Just then, Han Bin's cell phone rang.

Han Bin took out his cell phone and looked at it. An unfamiliar number was displayed on the screen.

"Hey, this is Han Bin."

"Captain Han, this is Ma Tao. I am here in the administration building. Principal Chen Huafeng, who is on duty at the school today, heard that you came to the school to investigate the case. He also wants to see you."

"Okay, I still have something to do. When I'm done, I will go to the administration building."

After explaining the situation, Han Bin hung up the phone.

Wang Jinliang on the side said, "Captain Han, do you have anything to do with the administration building?"

"Principal Chen Huafeng asked me to meet."

Wang Jinliang persuaded, "Yeah, then you go quickly, we can just wait for the police officer here."

Sun Yuefen also echoed, "Captain Han, you go, we are waiting here."

Han Bin nodded, "Then bother you two."

"You're welcome."

Han Bin sent a message to Bao Xing explaining the situation, and then went to the administrative building with Guo Tianxu.

Principal Chen Huafeng seemed to be about fifty years old. He wore gold-rimmed glasses with a faint smile on his face. He had a bookish temperament. He looked very enthusiastic after seeing Han Bin.

"You are Captain Han, you are really young and promising, please come in soon." Chen Huafeng led Han Bin into the office and invited them to sit on the sofa.

Chen Huafeng's office is very simple. The deepest impression for Han Bin is that there are many books. The two cupboards are filled with books, and there are two thick stacks of books on the desk.

After Ma Tao introduced each other, he left the principal's office, and only Han Bin was left in the room.

"Captain Han, I heard Director Ma talk about the general situation. If you have any needs, just say, I and the school will try our best to assist."

"Thank you." Han Bin was not polite, and said straightforwardly, "I would like a list of staff on duty during your school vacation."

Chen Huafeng frowned slightly, "Is it limited to the teaching and research building, or is it a list of all the staff on duty in the school?"

"A list of all the staff on duty at the school."

Chen Huafeng sighed, "This time the school vacation is relatively long, each department has its own arrangements and responsibilities, and there are more staff on duty. This is a big project."

Han Bin said, "It's not easy to trouble you. If it is a trivial matter, I will directly ask Director Ma and Director Wang to help."

"Okay, I will let you know so that the various departments will submit the list of on-duty personnel, but this may take some time."

"It's okay, you can contact me when it's done."

"Yes." Chen Huafeng replied, "Do you have any other requirements?"

Han Bin pondered for a moment, "Does your school hire criminals for theft?"

Chen Huafeng said with a firm tone, "No, the academic qualifications and backgrounds of the teachers in our school must be strictly reviewed. If we really have a prior record, we will not use it."

Han Bin explained, “I mean not only teachers, but also other staff, such as cleaners, security guards, back kitchens, etc., including all those who work in the school.”

Chen Huafeng scratched his chin, "This...I really don't know."

"Then please help me verify it."

Chen Huafeng nodded, "No problem, I will ask the Personnel Office to assist in the investigation."

Han Bin changed the conversation, "Have there ever been any theft in your school before?"

"How do you say this. There are more students in the school, and the situation is more complicated. It is inevitable that petty theft is unavoidable, but in general it is the first time a teacher has been stolen."

"How did that male general teacher come from?"

"Remains donation."

Han Bin suggested, "I need a copy of male general teachers."

"This is no problem, I will ask Director Ma to send it to you in a while."

Han Bin asked a few more questions and left without asking any more clues.

As soon as I left the administration building, I saw Bao Xing standing at the door smoking.

Bao Xing pinched the smoke and walked over, "Han Team, Sergeant Guo, I tried to open the door with the key. All four keys can open the door, and they should all be the original keys. No problem.

"When I came back, I ran into Chief Sun of the General Affairs Office and gave her the key."

Han Bin nodded, "Have the technical department come?"

"Here, we are investigating the scene."

Han Bin returned to the storage room on the second floor of the teaching and research building. A total of three people came from the technical department. The leader was Ma Xiwen, who looked in his thirties and was already a little bald with a thick spectacle frame.

"Brother Marco, did you find anything?"

Ma Xiwen pushed his glasses with his elbow, "There is no obvious footprint at the scene, but some fingerprints have been collected and I am going to take it back for comparison."

"In addition, we have extracted the antiseptic liquid in the pool and will take it back to test the ingredients."

Han Bin thought for a while and said, “Some of the surveillance videos in the school can only be stored for half a month, but the suspect stole it a month ago. Can you try to restore the previous video?

Ma Xiwen pursed his lips, "Let's try, but the possibility of recovery is unlikely, and the clarity of the video will also have a certain impact."

"Thank you."