"Hey, is it a youth protection agency? I'm Detective Xu Mu here... Right... A girl named Luo Suiyi in the record sheet, she can't go to the north of the state tomorrow... Right... She has a clue to a case. What? Regulatory documents are also required?... Okay, then you send someone to send it. ”

After hanging up the phone, Xu Mu looked at Luo Suiyi, and didn't wait for him to say anything. The sound of the police station horn sounded again.

"Well, it looks like you'll have to wait for tomorrow. Xu Mu took Luo Suiyi to the small black room, closed the lock and said, "In view of your criminal record, you can stay here for one night tonight, and the auxiliary police will bring you food later." ”

“...”

Foggy city center, upscale neighborhood - Helenburgh. The area is full of high-end residences, traces of mansions that have been privately renovated by the owner, and there is once a mixed forest nearby, and many users still keep their courtyards in their original appearance, and the dense shade covers the entire street. Yes, in this kind of high-end community where neither rich nor noble, there was a murder.

When Xu Mu and Li Ming arrived, they found that the scene was heavily guarded.

"It seems that this time the matter is serious, and I don't usually see so many policemen. Xu Mu thought.

"How's it going?" asked Li Ming, the auxiliary police officer who recorded it.

"The deceased's name is Liu Yu. Before his death, he was a famous writer and one of the top ten outstanding young people in Wudu. The date of death will have to be confirmed later. The bodies were found by his wife, Chen En, and his friend Jiang Zixuan. ”

"Jiang Zixuan!?" Xu Mu didn't seem to have heard it wrong. The two walked to the living room and found the 40-year-old man pacing back and forth like a bear.

"Teacher?" Xu Mu took two steps forward.

"Who are you?" Jiang Zixuan looked at Xu Mu and looked at the resolute face that emerged from the shadows, "Ah, it's you." Xu Mu!"

Later, Li Ming learned that Jiang Zixuan was Xu Mu's junior high school teacher, and later for some reason, he resigned not long after Xu Mu graduated, and is now engaged in the position of writer. It's a pity that Jiang Zixuan has not achieved as much as Liu Yu, and he is famous all over the world, so he can only write some articles in some newspapers with children's columns, and his income is not high, and he lives in a cheap single room building in two stations next to him.

"Can you come over and make a record?" Xu Mu glanced at Chen En, who was still pressing the corner of his eyes with a handkerchief, and turned to Jiang Zixuan and said. Because of acquaintance, Xu Mu also did the work of the auxiliary police.

"I can too. Chen En's voice was choked.

Two hours later, Xu Mu's transcript was as follows:

Liu Yu and Chen En, as natives of Wudu, are preparing to fly to Vancouver tomorrow morning to immigrate. On the morning of December 8th, my friend Jiang Zixuan came to visit, the reason was to discuss part of Jiang Zixuan's children's section writing, after all, Liu Yu has been famous for a long time, and when he has the ability, it is normal to bring Jiang Zixuan to this young man for many years. After chatting until about 3 o'clock in the afternoon, Luo Luo, the woman next door to Liu Yu's house, came to visit, Jiang Zixuan left, Luo Luo and Liu Yu kept talking about the specific content of the book written by Liu Yu, Luo Luo left at about 5 o'clock. After Chen Enzai and Liu Yu finished dinner, they went to the hotel alone, leaving Liu Yu to code in the studio. At 6 p.m., Jiang Zixuan, who was discussing details with Zhang Xiushan, the editor-in-chief of the children's column, received a call from Liu Yu, saying that he would come to his house at 8 p.m. to talk about something. Jiang Zixuan and Zhang Xiushan went to a restaurant near Jiang Zixuan's house for dinner, and then went to Liu Yu's house, and it was exactly 8 o'clock when they arrived. He felt a little strange because no one answered the door, so he called Chen En. Before Chen Eun arrived, he went to the nearby coffee shop "Yang Deng" and waited for her while drinking coffee. At around 8:40, he turned back to Chen En's house again, and it happened that Chen En also came. The two entered the house together and found the body.

Liu Yu was hit in the back of the head by the murderer with a paperweight in Liu Yu's home at 6~10 o'clock in the evening on December 8. According to Chen En's records, no suspicious people have been found near his home recently.

One of the things that made me (Xu Mu) pay special attention to this case was the paperweight used by the murderer - this was the original thing in Liu Yu's house. Therefore, it can be inferred that there was a sudden, improvised murder at this time. There is another thing that cannot be ignored - the door of Liu Yu's house is locked. According to the confession of the first discoverer, the door to the house and the door to Liu Yu's studio were locked.

According to the results of fingerprint comparison, only the fingerprints of Liu Yu and his wife were detected on the doorknob of the door, and there were no traces of wiping on the door lock. Judging from the fact that the door is deeply locked, the door should have been locked since Chen En left. Chen En's reason for locking the door was that he was worried that Liu Yu would be alone in the studio, even if someone came in from outside, he didn't know, although this is a strictly controlled high-end community, but there are many crimes that will occur in the fog. The door to the studio was most likely locked by the prisoner from the inside. Unlike the door of the entrance, there are obvious traces of fingerprints being wiped off.

Judging from the above points, the prisoner is most likely to climb into the room through the window. However, there is a contradiction in this inference: the bandit who had no intention of killing someone broke in through the window, but the probability that he wanted to steal was very low. Even if it was the first time to go to Liu Yu's house that day, he could immediately know that there was nothing of value left in it. In fact, there is only one hypothesis to solve this contradiction: the prisoners went to Liu Yu's house twice that day. The first time I came, I did come to visit because I had something to do. However, after the man left Liu Yu's house (to be pretended, after pretending to leave Liu Yu's house), he immediately made a second visit. At this point, the man had already made up his mind something, so he entered through the window instead. Needless to say, this idea is naturally an "attempt to kill". We can assume that he had the murderous intent on his first visit.

If this is the case, who had ever been to Liu Yu's house on the day of the crime? The answer obviously pointed to two people: Luo Luo and Jiang Zixuan.

In the living room, Li Ming stood behind Xu Mu and watched Xu Mu draw a large circle on the names of Luo Luo and Jiang Zixuan.

"Luo Luo will contact you for the time being, let's take a look at Jiang Zixuan's situation first," Xu Mu thought.

"It's over for the time being, I'll send you back. Xu Mu looked at Jiang Zixuan and said.

"But Chen En's side..."Jiang Zixuan was still thinking about Chen En's state of mind.

"It's okay, the police have already contacted Chen En's mother's family, so they will come to pick her up. Xu Mu responded.

"Well, it's so late now. Jiang Zixuan hesitated for a moment and accepted Xu Mu's arrangement.

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(PS: Write a little more and add some reasoning elements)