After receiving authorization, with the approval of Liang Rui, a vacant utility room on the first floor of the office building of Tianlei Yuan was cleared out overnight and put in the necessary tables, chairs and furniture, etc., as the investigation room of Jin Yan and the three of them.

All the exhibits, including cake scraps and all the utensils and supplies in the cafeteria at the time, were carefully organized, placed in the evidence bag or box, marked in order, and placed on the evidence shelves.

Jin Yan and the three of them chatted with each other while sorting out their items and utensils.

"You mean, you didn't think it smelled right?" Yang Xuexin asked.

Jin Yan said what happened before.

"My classmate has been for more than three years, and I can't see that Wang Hai, you are fat, and your nose is so sensitive." Yang Xuexin praised.

Being praised by her like this, Wang Hai touched the back of his head and smirked embarrassedly.

"Xuexin, Er Fat and I didn't eat much cake because we noticed something was wrong in advance. How did you ......?" Jin Yan asked.

"Before I left, my family prepared some medicine in case I needed it. Among them, there is such a powerful antidote, which is extracted from alienated medicinal plants, and has the purpose of neutralizing the toxicity of all poisons. When it came to the end, I didn't have to think much about it to use it, and I felt that the detoxification effect was good, and I also used half of it for Mr. Lin. Yang Xuexin said happily.

"Rich people are good." Jin Yan said, "Such a bottle of antidote that may be life-saving when used urgently, ordinary people, or ordinary people, where can they get it, and they can't afford it if they are bankrupt!" ”

"Are you sarcastic about me?" Yang Xuexin's head was slightly tilted, and she asked with a hint of anger.

The head was kicked by a donkey, in a good sentence, can you hear the sarcasm? Jin Yan thought.

At this time, Li Lu, the captain of the security team, came in with a box, opened the box, and inside were three mobile hard drives.

"What is on the hard drive is a copy of the video recordings of various surveillance cameras in the kitchen and canteen the day before the incident today." "We've looked at it over and over again, and we haven't found anyone suspicious for the time being," he said. ”

"Thank you for your hard work, Team Li, let's put it on the shelf first." Jin Yan said.

Li Lu put the box away, his face was as uncomfortable as constipation, he felt that tonight's incident was a great dereliction of duty for him, the security captain.

"Jin Yan, now that you have been authorized by Captain Liang to investigate the matter, if there is anything you need me to do, you must not be polite, just give orders."

"Okay, please Captain Li strengthen the security around us, adjust the angle of the camera, and ensure the safety of this evidence room in our absence. If someone intends to destroy and steal evidence, then even if he is not the murderer, he has a great deal to do with the murderer! Jin Yan said.

......

It's late at night, but Tianlei Yuan is experiencing a sleepless night. The dormitories are brightly lit, punctuated by the screams of students in pain, and the corridors are filled with the hurried footsteps of medical staff and security guards.

Jin Yan wrote a diagram of the investigation on a mobile blackboard in the investigation room.

In the very center of the diagram are the words "Yuanqing No. 4", and an arrow issued from it points to the right side of the "Fan Xitong"; An arrow from it pointed to the "Mingda Cake Shop" written on the left, and an arrow pointed to the lower left corner, pointing to the three words "Yang Keming", but a question mark was put on the right side of the word.

"It is clear that the toxin is a synthetic toxin Yuanqing No. 4, let's put aside the identity of the poisoner and the purpose of the poisoning, we can have three guesses about the location of the poisoning." Jin Yan said, "One is the Mingda cake shop in Leijiang City, the second is the bus, and the third is the kitchen of Tianlei Courtyard. Let's start with the elimination method. ”

As he spoke, he wrote the words Mingda Cake Shop, Bus, and Tianleiyuan Canteen on the right side of the blackboard.

"At present, Mingda Cake Shop is the most suspicious. However, since we did not go to the scene to see it, nor did we ask the store's confession, we had to leave it first. ”

"On the bus, there are 44 teachers and students who took the bus from the city to Tianlei Academy this evening, plus the driver. The cake trolley is carefully placed prominently in the aisle. If someone does something to it during this period, even the slightest action will definitely not escape everyone's eyes. As he spoke, he drew a cross on the word "bus".

On the road from the cake shop to the bus, Yang Keming took care of it personally, and no one else had close contact with the cake. Either Yang Keming himself is the poisoner, or the possibility of poisoning can also be ruled out on this road. ”

"The bus arrived at about 9 o'clock in Tianlei Temple, and the time when the cake got off the bus and went to the cafeteria was about 9:04 to 05. From getting out of the car to locking the canteen door and leaving, Er Fat helped the whole process, and he and Yang Keming pushed them to the canteen, and there was no one else in the impression who approached or behaved abnormally. After putting it away, Er Fat felt unstable and felt that the smell of the cake was wrong, so he proposed it with Yang Keming, but it was not taken seriously. The time they locked the door and left the cafeteria was about 9:07 to 08 a.m. So, after putting his things away, he came to me again. He and I went to the captain again. The captain and Sister Wen Yue took us to Yang Keming to open the door, at this time, it was about 9:20. ”

"If the poisoning happened in the cafeteria, it would have been between 9:07 and 9:20, about 13 minutes in between. If the murderer had planned in advance, he had been secretly observing, and he would have unlocked and entered and injected the toxin as soon as they left, and there was still plenty of time in between. ”

Jin Yan said and took out a list: "This is the list of canteen employees, including Yang Keming and Er Fat, there are a total of seven people. Because of the early morning breakfast, everyone has a key to the cafeteria. Therefore, on the premise of assuming that the poisoning location is a canteen, these seven people are all suspicious. ”

Wang Hai had a bitter face: "In this way, I am still suspicious." ”

"The problem now is that the cameras inside and outside the cafeteria are not showing anything out of the ordinary. The camera outside the cafeteria is not aimed at the cafeteria door, and the camera inside the cafeteria is not aimed at the cake. After all, no one would have expected this situation and adjusted the camera angle in advance. If the murderer is an insider, it is not difficult to know the angle of each camera and avoid them. ”

Jin Yan pasted the list on the blackboard with double-sided tape. Then he took out another stack of papers, "This is the guarantee that the other five canteen employees just wrote, and they swore that they had not been to the cafeteria in the evening, because most of the students had gone out in the evening, they had less to cook, and it was easy to wash the dishes, and it was over in a while, and after locking the door and leaving, there were three people fighting the landlord in the house, and the other two were resting and the other was doing laundry. As for each other, whether it was possible for anyone to complete the crime in a few minutes, they were not sure. ”

"I analyzed it, and it still tends to have nothing to do with them. Because the matter of buying the cake was completely improvised by Team Liang, and it was not revealed to Tianlei Academy in advance...... It's not easy to make the plan so seamless in a short period of time. ”

"This is the last struggle, get up until tomorrow......" the mobile phone rang to the ground. In order to facilitate the investigation of the case, Liang Rui returned the mobile phone to the three of them for the first time, which had just been charged.

"Hey, Team Liang." Jin Yan pressed the answer button, and it was Liang Rui who called.

"The subordinates of the Tianlei squad and the local police and judicial bureau have taken control of Mingda Cake Shop and its owner." Liang Rui said, "I'll take over here, you guys go to the Mingda Cake Shop in the city right now, investigate the scene, and interrogate the confession!" ”