"Maintenance worker!" Lao Chen suddenly realized.

"That's pretty much what it means, but there are many professions for people who have an excuse to climb on the roof, and the professions related to the supernatural forum are also very obvious." Xu Tian said.

"I see, it's a broadband repair worker, right?"

"That's right, the maintenance broadband must appear in the resident's home, and it can also be controlled in the computer room or distribution box to disconnect the broadband, so that the resident will report for repair, then the maintenance worker will definitely go in person, so it is natural to enter the scene of the crime."

"In addition, broadband maintenance workers must understand network technology, and it makes sense to be able to lurk inside the supernatural forum."

"That's right! Ninety-nine percent of the murderer's identity is a network technician, and after repairing the broadband, the murderer can not leave for a while, and before committing the crime, the murderer can climb to the top of the building in the passage on the top floor, stay on the roof for one night, and leave the next day. Of course, this method can work in residential buildings, because the mobility of people in residential buildings is relatively large, and most of the broadband maintenance workers carry a backpack, which can be loaded with civilian clothes, and even if it is midnight after changing clothes, the murderer can come and go freely in and out of the residential building. But not at school, first of all, the victim cannot stay in the school building at night, the murderer can only let the victim come to school earlier, and early morning is the only suitable time for the murderer to commit the crime. But after committing the crime, the murderer can not stay in the school, if the police arrive at the scene of the crime to see through the murderer's methods, then the murderer will be blocked on the top floor, the murderer must be quickly withdrawn after committing the crime, because it will be troublesome later, it will be time to go to school immediately, if the students pour into the school in large numbers, then the murderer will not want to withdraw this day. I judged that the murderer should have come to a teacher's office in the school building the day before to repair the broadband, and after the repair, the murderer did not leave, and the murderer secretly climbed to the roof of the building and lurked all night. The school is different from a residential building, as long as the school has students, it is very difficult for the murderer to escape, because the murderer will look very dazzling among the students, and the school teacher will also recognize at a glance that the murderer is not a student of this school, let alone a teacher in this school, so the murderer must withdraw as soon as possible after committing the crime. At that time, the murderer did not let the victim cut his throat when he committed the crime, probably because the victim was afraid at that time, and the murderer had to withdraw as soon as possible, so he temporarily changed the method of manipulating the victim to commit suicide, so under the circumstances, it was the most convenient way to let the victim hang himself. ”

"I see, usually the students will close the windows after school the night before, and the time of the crime is relatively early, so it is likely that only the window opened by the victim in the whole building at that time is open, and if the murderer climbs down the passage to the roof, he is likely to meet other students who came to school early. If the murderer directly uses something like a rope to go downstairs, there is no way to recover the tool. ”

"That's right! So the murderer should have gone down the drainage pipe, but the murderer did not dare to step on the ground downstairs, which would leave traces, and the only way for the murderer was to jump into the window opened by the victim, and then go down the side stairs to the first floor, and then open a window on the side of the first floor, jump out and walk along the root of the wall to the wall on the side of the teaching building, and climb over the wall. ”

"But the murderer didn't expect that the victim would drag the ground before committing suicide, so that the murderer would leave footprints when he jumped into the classroom."

"And at that time, the murdered girl was a little frightened, and she was reluctant to commit suicide, so the murderer helped the girl hang herself after coming down the drain pipe, and she could not jump into the classroom at that time, and the only way for the murderer was to risk leaving a trace down the drain pipe, and then flow along the root of the wall to the bottom of the fence and climb out."

"Even if the killer doesn't show up, it will be easy for us to find him."

"So the murderer simply came out to provoke us, this time the murderer has no way out, either arrested, or struggled for the last time before being arrested, a murderer like this will definitely not be caught obediently, he will definitely choose to compete with us."

"You've been expecting that, haven't you? That's why I'm so confident. ”

"Humph! Let's go and protect Bai Qi! When the murderer has reached the end of his rope, he is likely to do something extreme. ”

Buzzing......

Lao Chen's phone rang, and during the time he answered the phone, Lao Chen's mood was very bad, and he didn't say a word during the whole process.

"What's wrong? Is something wrong? Xu Tian asked.

"We are still one step late, Bai Qi was already killed before dawn, and the police officer responsible for secretly protecting Bai Qi also just discovered Bai Qi's body."

"What's going on?"

"It was Bai Qi's roommate at University who found Bai Qi's body, and because the police were downstairs in the girls' dormitory, they rushed to the scene of the crime as soon as possible."

Lao Chen hurriedly drove Xu Tian to the scene of the crime, and fifteen minutes later the two came to Bai Qi's dormitory.

Bai Qi was not hung outside the window, but died on her own bed, the cause of death was a cut wrist, judging from the situation at the scene of the crime, Bai Qi was undoubtedly a suicide.

Xu Tian and Lao Chen's faces were very solemn, especially Xu Tian, who looked very self-blaming.

"It's all my fault! I should have thought of this since I had deduced in the morning that the girls might have been instigated to commit suicide, I had made a fatal mistake, it was not enough to send someone to protect Bai Qi, we did not prevent Bai Qi from committing suicide. Xu Tian blamed himself.

"I can't blame you completely, even if we summon Bai Qi to the police station for 24-hour care, it's useless, I've been a police officer for more than 20 years, and I've encountered many suicide cases, if a person has suicidal emotions, it's useless how you protect her, even if you tie her to a chair, she will do everything she can to commit suicide, so you don't have to blame yourself."

"That's true, but our clues may be broken, has the identity of the murderer been investigated?"

"I have just received an email from the police officer who is investigating the identity of the murderer, and as you said, the murderer is indeed a worker who installs broadband."

"The development of things may change, the murderer obtained our case by monitoring the supernatural forum, this murderer is very smart, from our monitoring of the supernatural forum, we can judge that we are forcing him to show up, and he also knows that he is desperate, in this case, he can still send a courier early in the morning, in this case, the murderer should not do superfluous things, so the murderer may not know that Bai Qi is dead."