The meeting place agreed between Song Bo and Shi Lao was Shi Lao's laboratory at Chuncheng University, and Yun Yang really took two bags of tea from home and came to visit Shi Lao with Song Bo and Yan Tao.

Professor Shi has silver hair, he has retired, and he is a professor who has been rehired by Chuncheng University. With the assistance of two assistants, after a pair of experiments with bottles and cans, the results came out in less than an hour.

Professor Shi pointed to a sample of sand that had been examined and said, "Song Bo, you see, after testing, it contains a substance that does not exist in other samples, or an element, which is a new element synthesized by the Jiangcheng Chemical Plant last year, although it is not very precious, but it is difficult to find in other places."

"So I concluded that this sand sample must have come from river sand in the lower reaches of the Songjiang River in Jiangcheng."

Yan Tao's eyebrows raised, hesitated for a moment, and asked, "I'm sorry, Shi Lao, take the liberty of asking, can you be sure?" ”

Shi Lao nodded and smiled: "Young man, you are a criminal policeman, this rigorous attitude is commendable, however, science is the same, it can't be false, this sand sample will not be wrong to come from the lower reaches of Jiangcheng, and it will not be too far, because the farther it flows, the more it will be diluted, and this substance in the river sand will be very small, and it will be difficult to detect." ”

Yan Tao nodded, held Shi Jiao's hand tightly, and thanked you: "Thank you, you have brought new ideas to my case-solving work, and when the case is solved, we will come to the door to thank you again!" ”

The second squadron gathered in Yan Tao's office again, and he said alone, straight to the point: "Ten days have passed since the female corpse case, and there are no too valuable clues so far, the main responsibility lies with me, it is a mistake in direction."

"Last night, after the inspection of the sand left by the suspected crime vehicle on the scene map, it was found that the components contained in it could only be the sand and soil of the lower reaches of the Songjiang River that flows through Jiangcheng.

"I analyzed it, this kind of sand is a necessary material for construction, and the sand of our Spring City is fished from the nearby Yuma River, so the sand and soil of all the construction sites in Spring City obtained by Tan Chang do not contain this component.

"The cost of the sand used in the construction mainly comes from labor and freight, so in terms of cost, everyone can only buy it nearby, so it can basically be concluded that the van transporting the body came from Jiangcheng, or from the construction site of Jiangcheng's oily sand."

Speaking of this, Yan Tao stopped to take a sip of tea, and Zhao Sihai sighed and said, "It's no wonder, why doesn't that mysterious van have any clues at all, and there are corpses, like aliens, no one knows who it is." ”

Guo Qiang smiled slightly: "Sihai, the source of the corpse has also been discovered, Xiaoxiao found a girl, she said that one of them is very similar to her classmate, and this girl happens to be Jiangcheng." ”

Zhao Sihai's eyes lit up: "It's really effortless, it seems that this case is going to be transparent." ”

Guo Qiang glanced at him: "To put it lightly, 'it doesn't take any effort to get it', you know how much effort Xiaoxiao has put into it, and almost all the groups in Spring City have been spread on the Internet, look at the little girl's eyes are dark." ”

Zhuang Xiaoxiao's face flushed: "Guo Tan, don't praise me, aren't everyone staying, the case can't be solved, and no one has a good life." ”

Yan Tao nodded: "Xiaoxiao is good, if the clues are valuable, the case is solved, I will give you credit, I want to meet that person today, if she is not willing to come to the team, she can also make an appointment outside, cafes, restaurants, anywhere, the funds are borne by the team, you can get this matter done today."

"Qiangzi, grasp the situation, if there is a breakthrough in Xiaoxiao, follow up immediately, if you need to go to Jiangcheng, you will directly find their criminal investigation team, we are sister cities, we often cooperate with each other, if you don't get it right, this case is theirs, they will cooperate."

"Sihai, you follow the line of Jiabao mini van, go directly to Jiangcheng, find their traffic police department, and call up the video of various vehicles going out of the city on February 16, March 17, and April 13, if you don't find the van, immediately return along the south line of the old Chunjiang Highway.

"You should know that there is no surveillance on that road, which is completely accessible to suspects.

"I still have a question, along the southern route of the Chunjiang Highway, the speed of the van is also an hour and a half away at the earliest, and according to the final identification conclusion of the forensic doctor, the time of death of the victim should be between 11 o'clock at night and 12 o'clock in the morning, Chen Wei found that the van without a license plate left at about 12:05.

In other words, even if the time of the victim's death was 11 o'clock, then there would be only 12:05 until the time when the body was dumped and left.

"Then, there are only a few possibilities, that is, the place of the crime is not in Jiangcheng, but in Chuncheng, or somewhere between Chuncheng and Jiangcheng, or in the car.

"I focus on thinking that it is unlikely that the crime was committed in the car, so, Sihai, if there is no trace of the van in Jiangcheng, you pay attention to the records of other vehicles leaving Jiangcheng from the direction of the old south line in the past three days, and then pay attention to whether there are warehouses, factories and villas in the middle of the old south line, and focus on checking several towns such as Zuoqiao Town."

The people of the two exploration groups set off, Yan Tao had just turned on the computer, and was about to write a simple summary of the previous work, when the office phone on the desk suddenly rang, and he knew that the people who made this call were basically colleagues from the detachment or bureau.

Sure enough, the call came from Yao Wenfu, the captain of the Seventh Brigade, that is, the Investigative Brigade, who was very old, he was already in his forties, and he used to be the section chief of the pre-trial department, but later the pre-trial was revoked, and he was also merged into the criminal police team, and his position was not promoted, and he became a captain, and he was actually responsible for the pre-trial work of the entire public security bureau.

After a few words of greeting and greetings, Yao Wenfu cut to the chase: "Taozi, my brother asked you for help, the squadron below messed up your burglary and rape case, except for the one that caught the current one, the other cases were not true, and the procuratorate's arrest department put forward a lot of opinions, so I had to ask my brother for a favor."

"Taozi, my brother knows that you are busy with a big case now, no matter what, you have to find time to help my brother check it, otherwise we will lose the adult, the kid surnamed Luo is too difficult, he was born as a soldier, and his bones are too hard, and the brothers can't gnaw it."