The floor of the roof is a concrete floor, and in our impression, such a cement floor, especially on a roof that has not been set foot on for a long time, must leave a lot of dust.

But the reality is different, just by the strong wind on the sixth floor, all the dust has been blown away, and there are no footprints left at all.

The staff of the technical team used a wide light source to survey the footprint and found a very shallow footprint outline, which could only be seen as a footprint, and nothing else could be seen at all, even the texture of the sole of the shoe.

However, this was a major discovery after all, and the technical team immediately took pictures and extracted the footprint.

It's just that we can't prove it yet, and this footprint was left by the murderer. The rooftop is a relatively open place, and the residents of the building can also come, and even other people can come.

"This footprint is also too vague and a little strange." After Jiang Tingbai extracted the footprints, he suddenly muttered.

"Indeed, it looks like it has been covered up." A technician said in a deep voice.

Jiang Tingbai suddenly frowned, and denied: "Indeed, this person should be wearing shoe covers and extracting fingerprints?" ”

The technician shook his head: "No fingerprints were found, especially in the gap in the wall, not a single fingerprint was found." ”

"Is the investigation careful?" Jiang Tingbai asked with some unease.

The technician looked at Jiang Tingbai and said seriously: "It is true that no fingerprints were found, since the murderer is wearing shoe covers, he will definitely wear gloves." Moreover, the murderer used extremely corrosive chemicals, and he was even more able to wear gloves. ”

Jiang Tingbai thought about it, and it was right. But this time, at least not completely without gains, at least the method of destroying the wall by the murderer was determined, and there were vague footprints.

The most important thing is to at least prove that this case is not an accident caused by the disrepair of the wall, but a well-planned murder case.

"Team Qin, is it possible to merge the case?" Xue Hang asked me suddenly.

I did not answer, because it is not enough to join the case at this time, and the two deceased cannot be joined for investigation just because they knew each other.

"Let's close the team first." After thinking about it for a long time, I said.

In the office of the serious crime team, everyone is at a loss, and there are many similarities between the two death cases of Du Tan and Xu Kuan, the victims of the two cases are junior high school classmates, and both attended the class reunion three days ago. In both cases, the modus operandi was disguised as an accident.

No valuable fingerprints and footprints were found in either case, and the footprints found on the rooftop were examined, and no valuable clues were obtained, only that it was a pair of size 42 shoes, and there was no way to accurately estimate the height and weight of the suspect.

"The laboratory department has completed the examination of the brick foam extracted from the rooftop, and the sulfate component has indeed been extracted in it, and it seems that the murderer did use corrosive chemicals to corrode the wall, so as to complete the method of committing the crime." Jiang Tingbai had just returned from the trace examination department and brought us back key clues.

With this key evidence, the case can be characterized as homicide.

"Is there a result of the investigation of Xu Kuan? Find out who brought him to the scene of the crime? I asked with a fixed steady.

This matter was investigated by Lin Zifan, and we all set our eyes on Lin Zifan.

Lin Zifan was a little embarrassed, he wanted to speak and stopped, and finally said weakly: "For the time being, we haven't found any valuable clues, we have retrieved the call records of the deceased Xu Kuan, and there are no clues." We investigated his social media again, and the investigation continued, showing that there were no clues yet. ”

"To speed up the progress, now that Xu Kuan was killed, the clues point directly to the mobile phone buyer, and the mobile phone in his backpack is the most critical physical evidence." As I spoke, I suddenly thought of a key: "By the way, have you found Xu Kuan's bank card account?" Since there is a business dealing, there must be a money dealing. ”

Lin Zifan still shook his head and said, "I have already checked, and there is no money exchange." After all, this kind of shopping method still has to pay for it with one hand and deliver it with the other. ”

"I still think that the investigation should start from that class reunion, at least the deceased in the first case, Du Tan, was killed after returning home after leaving the class reunion." Li Meng pondered for a while, and then suddenly said.

"I agree with Li Meng's idea, this alumni association is likely to be the key to these two cases. What an obvious vendetta, this hatred is most likely an internal hatred between classmates. Xue Hang said seriously.

After listening to their speeches, I thought it made sense, but I still couldn't understand one question, that is, how much hatred there would be between classmates?

"The next stage of the case investigation focuses on investigating the contradictions between the students, they are junior high school classmates, and this contradiction is likely to occur in the junior high school school. If the two cases meet the conditions for merging and investigating, then Du Tan and Xu Kuan must be in the same contradiction. "I have formulated the investigation plan for the next step of the serious crime team, and everyone will perform their own duties, divide into several ways, and conduct investigations at the same time.

There were a total of 28 people attending the class reunion this time, and the amount of investigation was still relatively large, so we called Officer Wang again and asked him to lead the criminal police team to cooperate with us in the investigation.

And I, as the acting leader of the great serious crime team and the god of solving cases, are destined to take the unusual path.

I didn't take Li Meng to investigate this time, after all, there are not enough people now.

These 28 people all live in this city, and have studied in Ningzhou No. 1 Experimental Middle School, but as everyone grows older, everyone's work is in the field, and this class reunion is a miracle to be able to gather 28 people.

I went directly to Ningzhou No. 1 Experimental Middle School, ready to visit the class teachers of my classmates. The homeroom teacher is the parent of the student in the school, and although it has been so many years, I believe that the teacher is impressed with every student he has ever befriended.

When the teacher faces dozens of students in the class, the first thing he remembers must be two kinds of students, one is honest and obedient and learns well, and the other is the naughty thorn in the class.

So I was thinking, a group of junior high school kids, the so-called hatred must be fights, and then emotional objects and the like. The age of junior high school students is adolescence, rebellious period, which is easy to cause conflicts.

But this contradiction turned out to be a revenge killing ten years later.

The teacher must know some insider, today is the weekend, the school is closed, I inquired several times to learn the information and home address of their homeroom teacher.

Now I'm going to pay a visit......