Chapter 1238: Troublesome

Jiang Yuan looked over the data while sipping green tea. By the time the first cup of tea had lost its flavor, Wen Youchuan, a forensic expert from Jianjiang City, arrived pushing two suitcases.

Wen Youchuan had collaborated with Jiang Yuan several times and was quite familiar with him. Upon arriving at the scene, he greeted Jiang Yuan while opening the suitcases, beginning to retrieve samples batch by batch.

Samples in red, brown, yellow, green, and black were unpacked and laid out on the table.

As Wen Youchuan worked, he said, "Our Chief Wu gave strict instructions to cooperate fully and take good care of you. My junior colleague is back at the office organizing data; if you need anything, just ask, but don't tell Chief Wu that I was the one who said it..."

Jiang Yuan smiled and shook his head. He stood up and said, "Actually, I should have gone to Jianjiang City. Chief Wu is too impatient."

Under normal circumstances, Jiang Yuan should have been the one to go and examine the samples, but Wu Zhisu hadn't even offered that as an option.

Wen Youchuan laughed nonchalantly. "It's rare to find a case you're interested in. Chief Wu naturally hopes to keep the Jiang Yuan Cold Case Task Force in Jianjiang. If he lets you slip away, who knows when he'll get another chance to use you? Chief Wu complained last time that joining the Taihe River Working Group was costly, and he grumbled that the group didn't value Jianjiang's work enough."

*Sss-siss... *

Huang Qiangmin slurped his green tea, his lips making a wheezing sound against the rim of the cup.

Wen Youchuan glanced at him, then quickly looked away, his heart racing as he asked, "Where should we start?"

"Are there any bone marrow samples?" Jiang Yuan asked, referring to samples containing diatoms.

To the average person, it might seem that the lung tissue would be the sample containing diatoms, as the lungs are the first organ where diatoms settle if a person drowns in a body of water. However, bone marrow is the gold standard for diagnosing drowning!

This is because bone marrow is highly specific; diatoms can only reach it through the circulatory system while the person is alive. Therefore, finding diatoms in the bone marrow confirms drowning and rules out possibilities like post-mortem dumping of a body.

Of course, it doesn't mean that the bone marrow of every drowning victim will contain diatoms, but if a forensic expert has doubts about the cause of death, extracting bone marrow from long bones is the preferred choice—provided it exists.

Likewise, if a forensic expert has no specific need, they might not necessarily collect bone marrow samples.

Wen Youchuan nodded from the side. "There is only one case where bone marrow samples were collected and diatoms were found. The '1011' floating corpse case. It's an eight-year-old case."

"Did you handle it?" Jiang Yuan asked as he watched him skillfully retrieve the samples and the case file.

"I did, along with another forensic expert," Wen Youchuan replied. "The body was highly decomposed. By the time it was discovered, the muscle tissue had turned to mud, and the internal organs had autolyzed. During the autopsy, we found blunt force trauma on the head and fractures on the hand bones, so we opened a case."

Jiang Yuan nodded slowly, guessing that the organ autolysis was the reason they had performed the bone marrow diatom test.

Extracting bone marrow is relatively troublesome. Human leg bones are extremely hard, making them difficult to cut even with an electric bone saw. For a decomposed body, the bones are also slippery and greasy, making fixation a major challenge. The entire process is very physically demanding. In ordinary cases, unless necessary, forensic experts don't like to collect samples from there. The most troublesome part is that the extraction requires sterile conditions; otherwise, contamination from external diatoms would render the entire operation useless.

"Let's compare them, then." Jiang Yuan said, taking the bone marrow sample and examining it under the microscope.

Wen Youchuan began preparing the other samples from the same case, as well as samples from other cases.

As a forensic expert himself, he understood exactly what Jiang Yuan was doing.

The application of a diatom database is part of forensic botany, and the analysis and identification methods are similar. In general, diatom maps of water systems like rivers remain stable over long periods. Diatoms at different locations have various distinct species and morphologies, which gives the diatom map of any specific location its uniqueness.

Jiang Yuan was now comparing the diatoms in the samples. As long as there was a match, it would likely mean he had found the point of entry into the water or the dumping site.

For a drowning case, this was a major breakthrough.

In this context, a bone marrow sample is a 100% match for the point of entry. Other visceral samples—such as the liver, kidneys, spleen, and heart—could also show diatoms due to systemic circulation. Lung tissue samples are less reliable.

However, finding the point of entry is still a long way from solving the case. Wen Youchuan recalled previous drowning cases he had handled, silently preparing himself mentally.

Cases of this nature are always time-consuming and exhausting, but as police officers, they had no other choice...

As Wen Youchuan thought this, he also took a slow sip of tea.

Before long, Jiang Yuan looked up and gestured for the case file, beginning to read.

Wen Youchuan's tea suddenly lost its appeal. He leaned in and whispered, "Was there a match?"

"There was a match," Jiang Yuan nodded.

"Oh, it matched?" Wen Youchuan had imagined a small cheer or celebration, and for a moment, he didn't know what to say.

"This case fits, so let's start with this one. The 1011 floating corpse case." Jiang Yuan pointed to the final conclusion of the forensic report: *Complete diatoms detected in the right long bone marrow; inconsistent with water samples from the discovery site. *

"The conditions are quite suitable; no need to pick another one." Jiang Yuan explained, "The detection of diatoms in the bone marrow sample confirms drowning. The inconsistency with the water samples indicates that the discovery site was not the victim's point of entry. Of course, we now know the specific point of entry..."

As Jiang Yuan spoke, Qiao Shengli from the side printed out the address from the database and handed it to him.

"The body's point of entry was at Fan Family Village, upstream from Ningtai County. Check if there are any homicide cases or missing persons reports from that area," Jiang Yuan ordered Wang Chuanxing and the others, then turned to Wen Youchuan. "Is the body still there?"

"Only the bones remain. The body was too decomposed to be preserved," Wen Youchuan explained quickly.

For unsolved homicide cases, preserving the body is ideal. Even if a second autopsy yields poor results, it is still better than nothing.

However, highly decomposed bodies are indeed difficult to preserve. By the time organ autolysis occurs, it's not just the heart, liver, spleen, and kidneys that melt; the gastrointestinal tract also loses its structure, and its contents spill out—though that hardly matters anymore, as the odor of the body is already extremely complex and doesn't change much.

"Show me the digital photos." Jiang Yuan asked for the photos of the skull and hand bones from Wang Chuanxing.

"Political Commissar Huang, Chief Wu is here," a subordinate reported.

Huang Qiangmin stood up and looked at Jiang Yuan.

Jiang Yuan naturally reached into his pocket, took out the two-colored Guan Yu figurine he carried, and gave it a light rub.

Huang Qiangmin felt reassured.

According to their secret signal, this meant Jiang Yuan was confident he could crack the case—roughly equivalent to the difficulty of a single prayer to Guan Yu.

Huang Qiangmin straightened his clothes and went out to greet him.

Wu Zhisu walked in, full of energy, wearing a smile.

Before he could offer a greeting, Huang Qiangmin shouted, "Chief Wu, your case is truly a troublesome one!"

(End of chapter)