National Forensic Doctor-Chapter 1188 - 1118 Wool Socks

Liu Jinghui was playing with his phone, occasionally observing Jiang Yuan.

He was a cerebral person, naturally not needing to hunch over a microscope like a techie, studying back and forth.

This also let Liu Jinghui notice something strange. Originally, Jiang Yuan was looking at the manual and microscope, but now he seemed to be staring off into space, like a student zoning out halfway through class.

Liu Jinghui couldn’t help but chuckle; this state of Jiang Yuan was quite a sight for newcomers. If the police and criminals could choose each other, this look of Jiang Yuan would probably be chosen by many.

In Liu Jinghui’s mind, images of a dragon slaughtering an array appeared... Those sharp dragon claws, one grab, one throw, ended the lives of several criminals; the burst of dragon fire, one spray, one sweep, ended the lives of a bunch of criminals; the hefty dragon tail, one slam, one turn, ended the lives of a camp of criminals...

"I’m planning to invite Professor Su Lei and her team over." Jiang Yuan, at some point, retracted his gaze and began speaking seriously.

Liu Jinghui often analyzed the people around him, and he could tell that Jiang Yuan’s state was unusual, prompting him to ask, "Did you notice something?"

Jiang Yuan couldn’t exactly say he noticed a system task, so he spun his eyes around and blamed the microscope, saying, "The set of equipment bought by the Lanyue City Bureau is a bit troublesome; I can’t be bothered. Let Professor Su Lei and her team study it."

"Is it really that complex? I saw you use microscopes and stuff at other police stations, handling everything with ease." Liu Jinghui just remarked offhandedly and then said, "So, make the call. While we wait for them, what will we do?"

"Let’s have hot pot. My dad sent a lot of sliced beef frozen in the fridge." As Jiang Yuan spoke, he pulled out his phone to call Professor Su Lei.

The diatom database of the Taihe Basin project was done by Professor Su Lei’s team, and Jiang Yuan was considered a client to them. Coupled with the advantage of legal botany expertise, one call was enough for Su Lei to agree immediately.

After hanging up, Jiang Yuan said to Liu Jinghui, "That’s it for today, the DNA of Zhang Lei was just collected, and it’ll probably be tomorrow when we have a comparison result, let’s head back."

The time required for DNA comparison varies with different specimens; the quickest and simplest is blood, while in a decomposing body, blood is the first to spoil.

The criminal science lab of Lanyue City is quite strong, so Jiang Yuan didn’t have to worry about the normal procedures.

On the contrary, Liu Jinghui, following Jiang Yuan and skipping work in broad daylight, felt a bit uneasy.

That night, Su Lei landed in Lanyue City with her doctoral student Qiao Shengli.

She’s been rather busy these days. Ever since her research direction included legal botany and she published two major papers, Su Lei not only had a continuous stream of academic conferences, but her collaboration with Jiang Yuan also brought attention from various police departments nationwide, frequently receiving invitations.

For a scholar from the Agricultural Research Institute, this was a very interesting and revolutionary life change. Su Lei was enjoying it a lot.

Qiao Shengli was even more excited.

They checked into a hotel that night, and the next morning, Qiao Shengli got up two hours early and put on full makeup to meet Jiang Yuan.

Jiang Yuan, as usual, treated them to breakfast at Yilan Residence.

The dumplings, with a crispy yet not hard shell and rich broth, received unanimous praise.

Qiao Shengli couldn’t resist eating two and then started staring at Jiang Yuan.

Even sitting down, Jiang Yuan’s height was noticeable, towering above those beside him.

As Qiao Shengli was contemplating what to say next while watching, the door to the private room opened.

"Captain Jiang, I happened to be having breakfast here too. I heard you came, what a coincidence." The deputy director of the film town, Dong Xifeng, had sweat on the back of his neck.

Behind him, two sleepy-eyed young beauties emerged, exchanged glances with Jiang Yuan, and together they sweetly called out, "Brother Jiang..."

Feeling inexplicably annoyed, Qiao Shengli ate two more dumplings!

...

Su Lei and Qiao Shengli had experience working outside; they brought all their portable equipment and notified the Lanyue City Bureau in advance to borrow larger items like ultra-clean benches.

The equipment not available at the Lanyue City Bureau was available at Lanyue University. With Dai Mingsheng handling it, scheduling was easily confirmed.

Su Lei, Qiao Shengli, and others immediately delved into busy work.

The remaining clothing fragments were not many, with most washed away. However, the investigation discipline of Jiang Yuan’s task force had always been strict, and the specially preserved clothing fragments, as well as some soil from the crime scene, were all usable for forensic botanical analysis. Especially the remaining wool socks, with the cuffs well preserved and covered with a lot of plant spores, their value increased.

For the deceased Zhang Lei, these socks should have been the most useful item he bought.

The spores needed for forensic botany can be as small as the nanometer scale; therefore, even a small pair of sock cuffs can provide a lot of information.

However, picking out each spore, mounting them on slides for identification is merely the first step; classifying and analyzing the spores is the most difficult task.

In this, there can be several levels for identifying spores. Legal botany Level 1 could probably recognize the genera of most spores, but that’s about it.

In the mammalian context, genus is like reaching the level of felis and canis. Taking canis as an example, there are eight species under this genus, including the gray wolf, coyote, African wolf, and Ethiopian wolf. To the average person, these different wolf species are generally indistinguishable.

And the familiar domestic dog is actually a subspecies under "gray wolf species."

This subspecies has 39 kinds, including the domestic dog, Arabian wolf, Arctic wolf, Mexican wolf, Siberian wolf, Florida wolf, Japanese wolf, Austro-Hungarian wolf, China wolf, and Mongolian wolf, etc.

From the names, one can see that mastering this step makes classification tasks much easier. Since the distribution range of some plants is limited, if one can identify the key plants, the range can be significantly narrowed.

Of course, ultimately, it relies on pollen diagrams. The pollen diagram composed of multiple pollen spores is akin to DNA, precise to the meter level, and essentially irreplicable.

Su Lei has roughly a Level 2 proficiency in legal botany, while Qiao Shengli is about full Level 1, so Su Lei can barely handle forensic botany work, but it’s very slow, requiring constant reference checking for comparison.

Qiao Shengli cannot independently perform forensic botany identification work; her experience is still shallow, and her accumulation in taxonomy sparse. She has hit her limit at recognizing the "gray wolf" species, needing to consult materials for further botanical classification, and requires serious cross-referencing even with the documents. For a murder case, this timing cost is unacceptable.

When Jiang Yuan handles cases with Legal Botany Level 3, it’s just barely adequate.

However, if he activates temporary +1, he can easily identify down to subspecies, even if he needs to check less familiar genera and species occasionally. For case purposes, identifying to this level already brings direct methodological changes.

In canis terms, Jiang Yuan is now like recognizing the difference between a husky and a golden retriever.

This means Jiang Yuan is very relaxed in the first phase. Similarly, botanists with this level, in categorizing and analyzing spores, can’t possibly fall short.

And witnessing this, Qiao Shengli couldn’t help but find it a little unbelievable.

She waited until Jiang Yuan took a break, quickly grabbed a thermos and refilled Jiang Yuan’s cup, and asked, "In this case, differentiating the primary and secondary scenes in the categorization phase should be very difficult, right? Which spores were contaminated at the primary scene, and which at the secondary? It’s easy to get confused, right."

"If it’s just distinguishing the first from the second scene, there are many methods." Jiang Yuan drank his tea and said, unburdened, "The most basic method is to reanalyze the spores from the secondary scene. By excluding the secondary scene spores, what’s left..."

"What’s left comes from the first scene!" Qiao Shengli eagerly interjected.

Jiang Yuan laughed a little, "It could also be spores brought by the killer."

The victim was moved post-mortem, likely contaminating with spores along the way, and contact with the murderer also inevitably involved spore exchange.

"Right, I didn’t think that far." Qiao Shengli, fully made up and acting cute, exuded a strong youthful vibe.

Jiang Yuan let out a small "gulp," swallowing before saying, "The places the victim went before dying could also have spore contamination."

"Yes, considering so many factors." Qiao Shengli frowned slightly.

"Sounds difficult, but analyzing one by one, it’s just so. The spores stuck from the places a victim went while alive would be more evenly distributed, with a lower spore quantity per unit area, primarily wind-borne plants. Meanwhile, post-death, the spores they come into contact with skyrocket exponentially when reaching the ground."

Qiao Shengli listened seriously, still frowning and nodding.

For her, this level of judgment was too challenging.

Jiang Yuan chuckled, "In this case, there’s also a trick."

"What trick?"

"Wool socks." Jiang Yuan continued to elevate the value of the wool socks, saying, "The victim would definitely have been wearing shoes while alive, so areas below the sock cuffs would not normally contact spores before death. Wool socks particularly retain spores well... In fact, just analyzing these wool socks is sufficient for forensic botanical judgment."