civil forensic

Chapter 132
Longde Village, Longli County.

This is the largest urban-rural junction in Longli County, and it is also the corner with the most flexible local industry and the most abundant human resources.

And in the corner of the corner, there is the place where the dead stand, a small scavenger hut, and a small yard surrounded by various construction waste.

There are similar temporary buildings everywhere here, some of which are built a little more squarely, and even try their best to maintain the level of the farmyard, and more of them slide down to the angle of the shack.

The deceased's scavenging hut was a little more square, and it was built on the side of the county road, not too far from it, and there were food stalls and farmhouses.

The more convenient access to the environment is also the capital for the deceased to survive by scavenging.

Because he was old and saved some money, the deceased usually bought some scavengers from his peers, and he belonged to the upper class of scavengers.

However, the yard, which looked decent from the outside, turned into a mess when we walked in.

Spots of blood can still be seen at the scene.

Jiang Yuan looked around, and most of what he saw were throwing blood.

The so-called throwing shape is mostly brought about by blunt weapons.The perpetrator attacks the victim with a blunt weapon, and the blood adheres to the blunt weapon. When the perpetrator wields the blunt weapon again, the blood will be thrown around.

The flinging bloodstains are diffuse to a certain extent, and the bloodstains themselves are relatively uniform in size.

A small scientific experiment can be very good to see the throwing blood. Find a shit stick, take some bananas, mash them, add water and an appropriate amount of flour, stir evenly, and it will be sticky like blood, then you can use it The stick was dipped in the sticky substance and waved, thus observing the throwing bloodstains.

Looking at the traces of blood, we can see that the old man who scavenged waste was hit by a blunt object. It should have been hit many times, and the cause of his final death should also be inseparable from it.

"The blood has been sampled. But it can be done again." Seeing that Jiang Yuan was concerned about the blood, Wang Lan said something.

Grassroots police don’t pay much attention to bloodstain analysis, because people actually don’t need to pay attention to the process of the deceased being beaten or killed. What everyone wants is the murderer’s information, preferably straightforward DNA or fingerprint.

As Jiang Yuan et al. have done now.

In fact, everyone does not know whether the murderer has left fingerprints and DNA clues, but for this hope, a lot of manpower and material resources will be invested to find it.

Domestic homicide cases generally like to use stupid methods to solve the case. Perhaps the manpower and material resources given are too sufficient, so that the most hard-core or even the most stupid method has become the mainstream mode of solving the case.

Such as screening, such as DNA and fingerprints of all employees, etc.

This is unimaginable in European and American countries.Some countries in the Anglo-American system will not allow residents of a community to do universal DNA and fingerprints.

However, in response to domestic homicide cases that must be solved, such as this case, after the DNA test materials are collected, if the suspect is still not found, it may be necessary to do all the DNA of the residents in the nearby urban-rural fringe area.

Even if the effect is not ideal, I will do it.

However, this stupid method is also a guarantee for a solid increase in the success rate of solving crimes. The domestic murder detection rate is extremely high in the world.

Jiang Yuan didn't need to explain to Forensic Wang how his bloodstain analysis was.

In fact, he just looked at it and was able to make a certain description of the state of the crime scene in his mind.

In Jiang Yuan's mind, after being injured, the old man who scavenged waste was being beaten non-stop, and he was hiding from XZ in the hope of avoiding the attack.

That is, during this process, the storage racks he stood in the courtyard were constantly being knocked apart and fell.

These storage racks were assembled by the old scavengers themselves. They are mainly a combination of wood, and there are also semi-finished products such as wardrobes and open hangers used in clothing stores.

Anyway, the old man remodeled it, and it was filled with various objects, most of which were clothes.

And all these things, now all scattered in the yard, some stained with blood, some may contain the murderer's DNA.

A local criminal policeman from Longli County came over and saw that Jiang Yuan was focusing on the clothes, so he said to Jiang Yuan: "The waste textiles can be sold for a lot of money nowadays, but the receivers have relatively more requirements. Usually, a certain amount within a certain period of time is required, and the old man’s physical strength is not enough, so he has to save and sell together.”

Jiang Yuan nodded slightly: "I thought there would be a lot of wrapping paper and the like."

"It's the hard currency of the scavenger class. The old man put it in the house." The criminal policeman opened the cabin inside as he said that.

It is a self-built house, so the height is very limited, at most two meters, and the bed used inside is also in the form of a kang, which is probably a craft learned by old scavengers when they were young.

The most in the house is cardboard, and then there are some metals, and a small amount of daily necessities.

"The DNA in the house should also be taken, but now the crime scene is the priority." The criminal policeman said, looking at Jiang Yuan, and said kindly: "Jiang's forensic doctor is very involved, I know you are very busy, and the work in this county and the province is also very important." Many, this case is really too busy to ask for help."

Jiang Yuan said politely: "It's right to help each other."

"That's what I said, but this time we said we were asking for help. We specifically said that we hope to ask for help from Ningtai County." The criminal policeman introduced himself and said, "You may not remember, but you once helped us break through through fingerprints." A backlog... I took over at that time."

"It's so predestined." Jiang Yuan remembered the accumulated cases in Longli County, which were the cases when he first started fingerprinting. "

The criminal policeman nodded, and said in a low voice: "I am Zheng Xiangqian from the serious crime team here. I am directly in charge of this case. If you need anything, you can come to me directly. This trip, whether you want to take fingerprints or forensic evidence, it is up to you." Row."

Zheng Xiangqian handed a business card to Jiang Yuan.

Strictly speaking, collecting DNA evidence is not the job of a forensic doctor, but the job of an on-site survey technician.

However, in the police station in Qinghe City, the technicians doing field surveys are too basic. In terms of the level of detail in DNA, they may not be as good as forensic doctors.

And Jiang Yuan's fingerprint ability may be more trusted by the criminal police.

Jiang Yuan put away Zheng Xiangqian's business card, added the other party's WeChat, returned to the yard, and asked, "So... how tall is the victim?"

"It's relatively low, about 1.5 meters. He looks a little stooped." Zheng Xiangqian was about to leave, but now he stopped and asked, "What do you think?"

"Don't use you, it sounds weird." Jiang Yuan said, "I think, if the height of the things on the shelves that the victim knocked down when he was beaten, it should be possible It may be easier to extract DNA if it hits the murderer at the corresponding location?"

"This is indeed." Zheng Xiangqian nodded in agreement, but he didn't show much.

Jiang Yuan saw it, and asked, "Has someone brought it up already?"

"Yes." Zheng Xiangqian said: "We focused on extracting the DNA from these items in the early stage, but we were also worried about the incomplete extraction. Therefore, there are also factors in this aspect when applying for support."

If it is an ordinary item, it is actually relatively simple to extract DNA, especially the items in the household locker, which usually should not have DNA on it, because after a long time, the DNA activity left behind will be lost .

Even if there is DNA, it should be the DNA of family members in the first place. When encountering other people's DNA, you should pay more attention.

But the old people who scavenged waste all picked up things, many of them were clothes and so on, which made the DNA on them very confusing.

Moreover, unlike what most people think, all the DNA can be extracted by putting a piece of clothing in front of the inspector.

The actual DNA extraction is still to select a small spot, wipe or cut the clothes directly, and then enter the DNA laboratory, and it is not immediately possible to match.

There is a very critical step here called purification.It is to select a specific DNA fragment for amplification.

In short, to detect all the DNA on a piece of clothing, it is necessary to sample the clothing a little bit, hundreds or thousands of times is not too much, and several times or dozens of times is not too little.Even so, it is possible to miss a piece of DNA during stages such as purification.

But in any case, the more DNA extracted, the better.

Jiang Yuan followed Wu Jun and prioritized the blood-stained items.

Most of these bloodstains belonged to the victim, but if they were not all, there were murderers.

As we all know, beating someone, especially beating someone to the point of death, is still very likely to injure yourself.

Jiang Yuan also made full use of the ability of bloodstain analysis to try to find some clues.

It's not easy, it can even be said to be very difficult.

The crime scene this time, regardless of its small size, is more complicated than the usual four or five crime scenes in terms of complexity.

Jiang Yuan, Wu Jun and the others quickly fell into the vast sea of ​​things.

(End of this chapter)