Attending ex-girlfriend's wedding, arresting the groom's officer on the spot

Chapter 387 The identity of the second corpse
Sun Jun cooperated with the map detective to investigate the surveillance on the ring road, focusing on the inspection of vehicles a month ago, especially the vehicles that entered the ring road from Beishan and exited from the garbage dump.

This workload is actually not small. The cold storage here in Beishan is the largest cold chain transfer base in the north of Haizhou City.

Hundreds of cold chain transport vehicles enter and exit this cold storage area every day.

According to the traffic management requirements of Haizhou City, cold chain transport vehicles can only travel from the ring expressway and cannot enter the inner ring.

This results in that all vehicles entering the Beishan cold storage must enter and exit at the entrance and exit of the Beishan Ring Road.

Fortunately, there is a restriction on the exit of the garbage dump, and cold chain transport vehicles travel long distances, and the central highway is connected to the expressway when exiting or entering.

"Mark this car."

Sun Jun was personally in charge. A month ago, with a unit of less than a week, every vehicle entering the garbage dump on the ring road was not spared.

In the current investigation laboratory, Yang Sen is conducting DNA identification analysis on the second corpse.

"How about it?"

"I just made two bone marrow cuts, but they failed during processing. Now I'm doing the third one."

The success rate of DNA identification analysis is not 100%, it mainly depends on the activity level of the test material.

Judging from the degree of decomposition of the second corpse, there shouldn't be much of a problem in successfully identifying it, but it will definitely be more time-consuming.

"Try it, try it a few more times, if it doesn't work, then you can only look at mitochondrial DNA testing."

After hearing this, Yang Sen felt a little embarrassed: "Identification of mitochondrial DNA... I guess it's quite difficult."

There are generally three methods of DNA identification.

The most commonly used method is conventional chromosome identification, which is based on blood cells, hair follicles and other testing materials.

This method is actually to conduct a comprehensive measurement of human double helix DNA, and then compare it with the target DNA by dividing segments.

The detection technology of this method is very mature, and the detection reagents are all pre-made reagents. General field survey technicians can master this identification method after training.

Another commonly used method is Y-chromosome DNA identification. In most cases, this DNA identification method is used more often in the determination of health cases.

What is relatively rare is the mitochondrial DNA identification method, which is different from Y chromosome DNA identification. The former belongs to paternal inheritance, while mitochondria belongs to maternal inheritance.

This identification method is most suitable for the identification of autolyzed corpses, because the nuclei of autolyzed corpses rupture, the entire genetic material inside penetrates into the cells, and the cell membrane gradually disappears.

However, this method is extremely rare, because generally the first two DNA identification methods can meet the vast majority of crime-solving needs.

The process of mitochondrial DNA identification is complicated, and reagents need to be prepared, which are not readily available, and the technical requirements for on-site investigators are very high.

In the current field exploration laboratory, Liu Guodong is more certain of success, while Lu Chuan is the best.

Lao Bai basically doesn't know how to do it, and Yang Sen's success rate is very low.

"It's okay. Let's do it as usual first. If it doesn't work, we'll think about the mitochondria."

This was also after Lu Chuan came and built a trace evidence analysis laboratory, so that mitochondrial DNA identification could be done only after the equipment was updated. It could not be done without using the old equipment.

Now, the entire criminal investigation detachment is like a precision-operated machine, and every department is busy.

Even the stray dogs raised in the back kitchen were squatting at the back door with their ears raised, their big eyes staring at everyone who came close, as if they could spot the murderer.

The day passed quickly.

At ten o'clock in the morning the next day, Qin Yong hosted a case report meeting.Everyone who had stayed up all night had black circles under their eyes.

Many middle-aged policemen who started to have bifurcated hair after peeing got their wish and lived in the office.

Without a wife or children, I can smoke whenever I want, which greatly improves work efficiency.

"I'll report first."

Sun Jun stood up and walked to the projector: Yesterday afternoon and evening, we investigated all the vehicles that passed through the entrance and exit of the ring road garbage dump a month ago, with a time span of one week as the time range. "

The murderer had to use a certain method to dump the body anyway. The body could not appear in the garbage dump out of thin air, so as long as the murderer had been to the garbage dump and set off from Beishan, there was a high probability that he would pass through this intersection.

"There are many vehicles coming out of the Beishan cold storage, and there are also many vehicles entering, but there are not many vehicles coming off the ring road from the Cangfanggou garbage dump."

"There are 130 vehicles in total. Last night, we identified the drivers through the traffic control system."

"I have already photographed five groups of people in the morning to conduct investigations on these vehicles. I estimate that the results will be available within two days."

Qin Yong thought for a while: "The number of people is still small. I reported it to the director yesterday. The case is serious. People from the municipal bureau can be removed if necessary. First, we should transfer people to the police station, increase manpower, and coordinate the traffic police, and strive to do it in the shortest time. Find these vehicles.”

"Yes."

In this case, Sun Jun's team can speed up the investigation progress.

"Ren Qiang, how is your investigation going?"

"There are 32 cold storages. Yesterday we joined forces with the fire department to complete detailed inspections of [-] cold storages in the name of fire inspection. No problems have been found so far."

"Today and tomorrow, we will try to complete the remaining cold investigation."

"The speed is still a bit slow. If manpower is needed, I will communicate with the fire department and send more people. We must complete all the remaining 21 cold storages today."

"Yes."

Next, is the forensic report.

"The body should have been in the garbage dump for more than two months, and the specific time of death should be within this range, but I cannot guarantee whether this body has a history of being refrigerated like the previous body."

"The judgment on the time of death is relatively vague."

"Because the surface features of the body were severely damaged, there is currently no way to determine the cause of death."

"But what is certain is that the dismemberment method of this corpse is similar to that of the previous corpse, and compared with the previous corpse, there are signs of improvement in the dismemberment method of corpse No. [-]."

Although the judgment given by the forensic doctor is relatively small, it can be initially determined that the murderer is the same person.

"Where's the current survey here?"

Qin Yong has seen the corpse, and it appears to be very badly decomposed. Such an autopsy cannot give many clues.

"Two things have been discovered during the current investigation. First, clay from Beishan was also found in the box containing the body."

This further supports the forensic doctor's judgment that the murderer of the two corpses should be the same person.

"Second, just ten minutes before the meeting, Yang Sen found out the identity of the second corpse through DNA identification analysis."

(End of this chapter)