Mystery Tracker 2

Hearing what Jiang Ruiheng said, Shen Yan immediately sat up straight: "Really?"

"Don't be so excited," Jiang Ruiheng waved his hand, "The implementation of this plan is not so easy, and the workload is heavy."

Cheng Jinsong seemed calmer than Shen Yan, and he said, "Ruiheng, what plan are you talking about?"

"Y-STR, family line investigation method, have you heard of it?" Jiang Ruiheng looked at Cheng Jinsong.

Cheng Jinsong was startled for a moment, then stroked his chin as if realizing something.

Seeing Cheng Jinsong's expression, Shen Yan knew that this method was by no means unreliable, so he asked, "What method is this?"

Seeing that Cheng Jinsong was still thinking, Jiang Ruiheng explained to Shen Yan: "It's a method to use DNA to identify suspects. In male sex chromosomes, the genes on the Y chromosome all come from the father, so if you don't consider In the case of gene mutation, the Y chromosome in a paternal family should be completely consistent. That is to say, all male individuals in the paternal line, including brothers, father and son, uncles, cousins ​​and grandchildren, have the same Y -STR haplotype. So through the Y-STR detection method, we can find the position of a DNA in the family tree. There have been successful cases of using this method to identify suspects before. Jiang Xin and I have studied it in the past two days. I think we can also try this case.

Jiang Xin continued: "I heard from Forensic Doctor Jiang that the previous chewing gum had locked the suspects in Shabei and Yunxi counties. These two counties have a large rural population and relatively dense kinship. It should be relatively easy to use Y-STR to investigate." suitable."

Jiang Ruiheng nodded, and then explained: "We already have the two basic conditions for using the Y-STR screening method: male suspects and mastery of their DNA. And there is another comparative advantage in this case, which is the point mentioned by Jiang Xin just now. The area we are currently targeting is the rural area, where the phenomenon of family clusters is very obvious. A village is often composed of several large families. And the Y-STR genotypes of a family are consistent, so this method should It can quickly help us eliminate a large number of suspects and quickly narrow down the scope." Looking at Shen Yan's eyes gradually ignited with hope, Jiang Ruiheng added: "But I have to declare in advance that even if there are the above-mentioned favorable conditions, the current suspects may be The area of ​​existence is too large, and it is estimated that a large number of samples will need to be taken in order to investigate, so the workload must not be small. In addition, it may not be a small problem to convince the villagers to agree to provide their DNA."

Jiang Ruiheng explained the pros and cons clearly, Shen Yan frowned and thought about it, then looked at Cheng Jinsong and said, "Jin Song, what do you think?"

When the few people were talking just now, Cheng Jinsong had been thinking about Jiang Ruiheng's plan. Hearing Shen Yan's question now, he said: "I think this is probably the best way based on the clues we have so far."

Shen Yan nodded: "I think so too. We have checked all the clues before, but there is nothing to gain. Now there is such an effective method, so we have to try it no matter what." He said Looking at Jiang Ruiheng: "Ruiheng, you will be in charge of this matter. If you say what we need to do, I will let other people fully cooperate with you."

Jiang Ruiheng obviously came to Shen Yan after enough thinking, so Shen Yan nodded, and he immediately proposed a further plan: "If we want to use this plan to investigate, sampling is the key. On the one hand, we have to collect all the different The DNA samples of the relatives are all collected, so as to ensure that there are no omissions; on the other hand, the analysis of the samples must be accurate to ensure that there are no mistakes."

"Don't worry about the sample analysis, we will leave it to our team," Cheng Jinsong said, "I can send two people to go with you, and they will be responsible for sending the samples back to the city for inspection every day. You don't have to worry about the accuracy. If you take samples If you need people, Xiaorou Jiayu and the others can help you."

"As for the mobilization, we will leave it to us." Shen Yan said, "Li Yuan and the others can go to the local area to do work. And I will also contact the Shabei and Yunxi branches in a while, and ask them to send people to fully cooperate with our work." Work."

Jiang Ruiheng nodded.

Jiang Xin had been listening to the arrangement of several people, and heard this and said: "As for the sampling, if we want to ensure that the sampling is complete, we must have a clear understanding of the family relationship of the people in the suspected area. That is to find out. How many families are there in this area, and who are the members of each family? Therefore, Team Shen, I suggest that you ask the household registration police of the two sub-bureaus to cooperate, first make a family tree map of the local residents, and then we Then sample according to this pedigree. As for the actual blood collection, I don’t think it is particularly difficult, because there are often many males in a family, and it should not be too difficult to find one who is willing to provide blood samples. However, in order to avoid genetic mutations. error, so I recommend collecting blood samples from at least two people in each family."

Shen Yan listened to Jiang Xin's words, then looked at Cheng Jinsong and Jiang Ruiheng, and saw that the two had no objection, so he nodded: "Okay, then I will contact the Shabei and Yunxi sub-bureaus in a while, and ask them to cooperate. Then you Also make relevant preparations, we can take a two-pronged approach, sampling and investigation at the same time."

"it is good."

"Okay, let everyone know that there will be a meeting in the conference room in 10 minutes."

After 10 minutes, everyone gathered in the conference room.

Shen Yan first briefly introduced the decision to use the Y-STR screening method for the next step of the investigation, and then asked Jiang Ruiheng to introduce this method.Several people in the serious crime team did not expect such a method, and they couldn't hide their excitement on their expressions.

"Ruiheng, there is such a method, why didn't you say it earlier?" Cheng Haiyang complained, "It also saves us from bumping into walls like headless chickens these days."

"It's not as easy as you think," Jiang Ruiheng shook his finger. "Didn't I just say that this method is a lot of work. If it weren't for the fact that there is no clue about this case, I would not propose this method."

"Hey Ruiheng," Qin Kai said, "As you said, we really don't have a clue about this case so far. It's rare that we have a solution now, and it's so reliable. Even if it's a bit tiring, it's worth it!"

Qin Kai's words should be regarded as expressing everyone's aspirations, and many people nodded in agreement.Shen Yan saw that no one had any objections, so he said: "In this case, we will investigate according to this plan. There are two key points in adopting the family investigation method. One is that we need to sort out the local family relationship and ensure that Count all the male population; second, each family must provide a certain number of male blood samples for testing. So in the next few days we arranged this way, the serious crime team is responsible for the investigation of family relations, with Li Yuan as the team The head of the police station, together with the household registration police of the sub-bureau, sorted out the local male family relationship as soon as possible; the forensic team was responsible for taking blood samples from each family member; the forensic team first dispatched a few people to help sort out the local population relationship, and later the blood samples increased Afterwards, all the staff are responsible for the inspection and comparison of blood samples. It has been almost four months since the case was reported, and we must strive to find the suspect as soon as possible and solve the case as soon as possible!"

"Yes!"

After confirming the plan, everyone immediately threw themselves into a new round of busy work.Due to the large scope of investigation, everyone decided to investigate step by step according to the principle of from near to far after discussion.The first batch of targets were targeted at nine villages and towns around Jingyun Town, where the crime occurred.The Serious Crime Squad contacted the Yunxi County Police. Captain Liu of the Criminal Investigation Team of Yunxi County had obviously never heard of the term "Y-STR" or "Family Investigation Method". understand.But there is one thing he understands, that is, with this method, it is very possible to find the murderer.

"Captain Shen, Forensic Doctor Jiang, I know you have a solution. Just tell us how we need to cooperate!" Captain Liu said straightforwardly.

"Captain Liu, we need to know the kinship and family relationship of all the male population in the target area." Jiang Ruiheng said, "That is to say, in the counties, towns, and villages under your jurisdiction, who is the father of each male population, who is his brother? Who is it, who is the son, who are the uncles and cousins, all these must be sorted out into a detailed family tree. It should be as complete as possible, without omissions."

After Jiang Ruiheng finished speaking, Captain Liu on the other end of the phone was completely silent for about half a minute.

On the other end of the phone, Jiang Ruiheng and Shen Yan looked at each other, both of them knew that Captain Liu obviously did not expect such a huge workload.Shen Yan then spoke into the microphone: "Captain Liu, I know it will be a lot of work, but now this is the most effective way we can solve the case. So please find a way to do this. I will also start from We will send people here to help you with this.”

"Captain Liu," Jiang Ruiheng also said, "Although this matter is a lot of work, it is not very professional. It is not only done by people from our criminal investigation team. The household registration police, the police station police, and even the village police of each village Cadres can assist in the completion. If you think it may be difficult to investigate the case, you can tell them that we are conducting a census... In addition, our blood sampling work will also be carried out at the same time, as long as one person in one family If the suspicion is eliminated, the entire family can eliminate the suspicion, so the final actual workload may not be as large as it sounds."

After listening to Jiang Ruiheng's statement of pros and cons, Captain Liu felt a little more at ease, and only heard his firm voice coming from the other end of the phone: "Zhong! We will do whatever you say. In short, as long as we can solve the case, no matter how much Difficult, we must complete the task!"

"it is good!"