134: Chapter 131 On-site Collection 134: Chapter 131 On-site Collection Longli County, Longde Village.

This is the location of the largest urban-rural junction in Longli County and the corner with the most vibrant local industries and the most abundant human resources.

And in the corner of the corner is the dead man’s place of residence, a tiny waste-picking hut, surrounded by a small courtyard fenced in with various construction waste materials.

Similar temporary buildings are everywhere here, some built more neatly, striving yet failing to maintain the level of a rural household; many others are slipping in the direction of becoming shanties.

The deceased’s waste-picking hut was one of those that were slightly more neatly constructed, and it was located right by the county road, not too far from where there were food stalls and rural restaurants.

The relatively convenient access was the capital the deceased had for surviving through waste-picking.

Because he was elderly and had saved some money, he would also buy other waste-pickers’ collections, making him one of the upper-class figures among waste-pickers.

However, once you walked into what looked like a decent courtyard from the outside, it was completely chaotic inside.

On the scene, you could still see specks of blood spatter scattered about.

Jiang Yuan looked around and saw that most of it was cast-off bloodstains.

Cast-off bloodstains are mostly caused by blunt instruments.

The assailant would attack the victim with a blunt object, blood would adhere to the object, and when the assailant swung the blunt object again, blood would cast off around it.

Cast-off bloodstains are diffused with relatively consistent sizes.

A simple scientific experiment can clearly demonstrate cast-off stains: find a stick, take some bananas, mash them, add water and an appropriate amount of flour, mix until it resembles the viscosity of blood, and then swing the stick coated in the mixture to observe cast-off bloodstains.

By examining the bloodstain patterns, one can trace the process of the elderly waste-picker being struck with a blunt object which likely was the cause of his death.

“The blood has been sampled.

But it can be done again,” said Wang Lan, noticing Jiang Yuan’s interest in the bloodstains.

Grassroots police don’t pay much attention to bloodstain analysis because they generally don’t need to concern themselves with the details of how a victim was beaten or killed; they want information on the perpetrator, preferably straightforward DNA or fingerprints.

Just as Jiang Yuan and his colleagues were doing now.

Everyone didn’t actually know if the assailant had left fingerprints or DNA clues, but they would invest considerable manpower and resources in searching for this slim hope.

Domestic murder cases generally prefer clumsy methods for solving crimes, perhaps because the resources provided are overly abundant, so the most straightforward—and even the clumsiest—methods become the mainstream approach to cracking cases.

Such as canvassing, and full DNA and fingerprint testing, etc.

This is unimaginable in Europe and America.

Some countries in the Anglo-American system wouldn’t allow an entire community to undergo widespread DNA and fingerprint testing.

But under the domestic edict that murder cases must be solved, like in the current case, if no suspect is found once the DNA evidence is collected, they might have to conduct full DNA tests on the residents of the nearby urban-rural areas.

Even if the results aren’t ideal, they would still go through with it.

However, these unsophisticated methods are solid guarantees for improving the success rate of solving crimes; domestic murder case clearance rates are extremely high on a global scale.

Jiang Yuan doesn’t need to explain to Doctor Wang how adept he is at bloodstain analysis.

In fact, he had taken a look and could already make a certain description of the crime scene in his mind.

In Jiang Yuan’s mind, after being injured, the elderly waste-picker was continuously attacked while trying to dodge and hide in hopes of avoiding the assault.

During this process, the storage racks standing in the yard kept getting knocked over and scattered.

These racks, all put together by the old man himself, were mainly made of wood, some half-finished pieces like wardrobes moved in, and open-style clothing racks used in clothing stores, etc.

In any case, after the old man’s modifications, they were all filled with various items, with clothes being the most abundant.

Now, all these items were scattered around the courtyard, some stained with blood, some perhaps containing the DNA of the assailant.

A local detective from Longli County came over, seeing that Jiang Yuan was focused on the clothes, and said, “These days, old textiles can sell for quite a bit of money, but the buyers usually have more requirements, often demanding a certain quantity within a certain time.

The old man didn’t have the physical strength, so he had to accumulate them to sell in bulk.”

Jiang Yuan nodded slightly, “I thought there would be a lot of packaging paper and the like.”

“That’s premium stuff among scavengers, the old man kept it in the house,” the detective said as he opened the door of the little room.

The room was self-built, so the height was quite limited, at most two meters tall, and the bed inside was also in the form of a traditional kang, probably a craft the scavenging elder learned when he was young.

The room was mostly filled with cardboard, then some metal, and a few personal belongings.

“We’ll need to collect DNA from inside the house as well, but the crime scene takes priority,” the detective said, glancing at Jiang Yuan with a friendly tone, “Doctor Jiang, I’m sorry to trouble you.

I know you’re quite busy with work here in the county and at the provincial level.

We only requested assistance because we’re swamped with this case.”

Jiang Yuan politely replied, “Mutual help is what we should do.”

“That’s true, but this time when we asked for help, we specifically hoped for assistance from Ningtai County,” the detective said as he introduced himself, “You might not remember, but you once helped us crack a cold case through fingerprints…

It was me who took over that case then.”

“What a coincidence,” Jiang Yuan recalled the cold case from Longli County; it was one of his first cases involving fingerprints.

The detective nodded, then whispered, “I’m Zheng Xiangqian from the major crime unit here, directly in charge of this case.

Whatever you need, you can come straight to me.

This time, whether you want to collect fingerprints or forensic evidence, it’s all fine.”

Zheng Xiangqian handed his business card to Jiang Yuan.

Strictly speaking, collecting DNA evidence is not really a forensic doctor’s job, but the work of a technical officer at the crime scene.

However, at the Qinghe City police bureau, the technicians doing scene investigations are all too basic; in terms of being meticulous with DNA, they might not even compare to a forensic doctor.

And Jiang Yuan’s capability with fingerprints might be even more trusted by the detectives.

Jiang Yuan took Zheng Xiangqian’s business card, added him on WeChat, and returned to the yard to ask, “That…

how tall was the victim?”

“Quite short, about one and a half meters tall.

He was a bit hunchbacked,” Zheng Xiangqian, originally preparing to leave, stopped and asked, “Do you have any ideas?”

“Let’s not be so formal,” Jiang Yuan said, and then added, “I was thinking, if the height is appropriate, the items knocked over on these shelves by the victim during the assault could have hit the assailant.

And maybe it would be easier to extract DNA from the corresponding places?”

“That’s indeed the case,” Zheng Xiangqian agreed with a nod but didn’t show much excitement.

Jiang Yuan noticed and asked, “Has someone else suggested this already?”

“Yes,” Zheng Xiangqian replied, “We’ve been focusing on extracting DNA from these items from the beginning, but we’re also worried we might not have collected everything, which is one of the reasons we requested support.”

If it were ordinary items, extracting DNA would be relatively simple, especially from household items in a storage cabinet, which normally shouldn’t have any DNA because the traces left behind would have lost activity after being there a long time.

Even if there is DNA, it should first be from family members; when you encounter DNA from other people, that’s when you need to pay extra attention.

But for a scavenger, the items are all picked up, and many are clothing items, which makes the DNA found on them very chaotic.

And unlike what many people think, that having a piece of clothing in front of an examiner means all the DNA can be extracted from it.

In reality, extracting DNA is still about choosing a small spot, wiping it or cutting the fabric directly, and then taking it to the DNA laboratory for processing; it’s not something that can be matched immediately.

There’s a very critical step here called purification, which involves selecting specific DNA fragments to amplify.

In short, to test all the DNA on a piece of clothing requires sampling it bit by bit, hundreds or even thousands of times, and several or a few dozen times is not excessive.

Even so, some DNA may still be missed during stages like purification.

But regardless, the more DNA is extracted, the better.

Jiang Yuan worked alongside Wu Jun, giving priority to items with bloodstains.

Most of these bloodstains belonged to the victim, but there’s a chance they could include the perpetrator’s as well.

As is well known, hitting someone, especially to the point of killing, runs a high chance of injuring oneself in the process.

Jiang Yuan also made full use of his Bloodstain Analysis expertise, attempting to find some clues.

This was not easy and could even be said to be extremely challenging.

This crime scene, although not large in area, was complex to a degree that exceeded that of several ordinary crime scenes combined.

Jiang Yuan and Wu Jun, among others, quickly found themselves immersed in a vast sea of items.