Chapter 263

Charred bones are already very different from original, fresh bones.

Jiang Yuan took out the first bone from the evidence box; it had already been burned to the point of vitrification, the curvature of the bone surface had disappeared, and the bone was covered with several small bone fragments, many particles of coal residue, and small nodules formed by the melting of unknown inorganic substances.

At first glance, this bone actually looked more like a strange handicraft, but looking closely, one could see many details belonging to a bone.

As a forensic expert, Jiang Yuan could see more; for example, this was a piece of skull bone, and the whiteness of the bone fragment was caused by burning at a high temperature of over 1000 degrees...

And the organic matter on the bone had all been burned away, which meant that common DNA techniques were already ineffective.

Jiang Yuan took out the second bone without saying a word.

The degree of burning on this bone was slightly lower, appearing as if it had just finished carbonizing, not yet reaching the point of vitrification.

But still, the organic matter had all been burned away, and DNA methods were completely useless.

Jiang Yuan looked at the remaining dozen or so bones one by one, and they were all in a similar situation.

The difficulty level had suddenly spiked; it meant that traditional techniques like DNA were of no use at all, and the only thing to rely on was the most traditional forensic anthropology.

Looking on the bright side, many bones in tombs or mass grave sites also have terrible bone quality.

And when it comes to difficulty, traditional forensic anthropology has always been extremely difficult.

There are too many ambiguities, too much experience, and too many regression formulas. There are many things that one simply cannot understand by reading books normally, and even the authors cannot express them clearly; one must have master-apprentice inheritance to understand them.

It's like trying to describe the feeling of snot sticking to the back of your hand, the feeling of tears wiped on it, the feeling of rice wiped on it, the feeling of water shield soup wiped on it, and the feeling of beef soup wiped on it.

Although human vocabulary is already very rich, accurately describing tactile sensations, let alone mapping them one-to-one, is basically impossible.

Forensic anthropology is dealing with exactly these things.

What is the tactile sensation of fresh bone, what is the tactile sensation of charred bone, what is the difference between touching a skull and facial bone, what is the difference between touching finger bones and toe bones...

Because forensic anthropology deals with these seemingly simple yet extremely fragmented pieces of knowledge, without a teacher's hands-on guidance, it would be very, very difficult.

As far as Jiang Yuan knows, there are two renowned old forensic experts in Shannan Province who are often borrowed by the ministry, borrowed by provincial bureaus of other provinces, or traded away by the leaders of their own municipal or county bureaus.

If forensic experts are relatively scarce at the county level, then forensic anthropologists are extremely scarce nationwide and even worldwide.

This mainly refers to those who are good at it; the mediocre ones don't count.

Jiang Yuan shook open the forensic report made by the Changyang City forensic expert to examine it closely, scoring it internally; he estimated that this person's forensic anthropology ability was around lv2.8 to lv3.2.

The knowledge reserve is at the level of about 320 Wang Zhongs.

This is already a very strong forensic expert. Jiang Yuan estimated that it should be the work of Shannan Province's top 2.

Jiang Yuan flipped to the top of the forensic report and sure enough saw the name written in the appraiser section: Zhang Fengtian.

Jiang Yuan couldn't help but say: "Forensic Expert Zhang has already done the appraisal, so there's no need for me to look at it again."

As he spoke, he picked up the bone and looked at it for a second time.

Yu Wenshu saw through Jiang Yuan's insincerity and said: "Forensic Expert Zhang did provide an appraisal report, but it only confirmed that they were human remains. We don't know the gender, age, or height. Our main investigation direction now is a furnace that can reach over 1000 degrees. Everyone has visited many places, but there are no clues..."

While burning a corpse certainly destroys a large amount of evidence, the process of burning a corpse actually creates new clues.

For example, the method of burning the corpse, the technique, the equipment, the fuel, etc., are all issues.

Completely vitrified bones require high temperatures of over 1000 degrees, carbonization requires 800, and from 800 to 1000 degrees is exactly a threshold that ordinary civilian furnaces cannot reach.

Jiang Yuan nodded as he listened: "There are only skull, chest, and vertebrae bones here; it is indeed not easy to determine gender, age, and height."

Yu Wenshu was a bit disappointed and turned to say: "The coal chunks on top, or these compacted particles, have all been extracted by the trace laboratory, but there are no results yet."

He was actually looking forward to Jiang Yuan playing a role outside of forensic science.

After all, most of the case-solving abilities Jiang Yuan has displayed are actually outside of forensic science.

Jiang Yuan roughly guessed Yu Wenshu's mood and didn't say anything or show any reaction.

Solving a case is different from many things; it's not that you will definitely succeed if you do it according to the leader's expectations or according to most people's imagination.

That kind of detective who has an idea and just lacks a "CSI team" is still far from solving the case.

"Forensic Expert Zhang's report is actually written quite detailedly. On the upper and lower surfaces of specimens 5, 6, and 7, a ring-shaped bone cortex structure wrapping the cancellous bone can be seen. Both the upper and lower surfaces are relatively flat, and the edges are slightly higher than the middle, so they are judged to be vertebral fragments. Among them, there is a missing transverse foramen on the posterior lateral side of the 6th vertebral body, judged to be a cervical vertebra, and lip-like marginal hyperplasia can be seen..."

Jiang Yuan commented and added: "In my view, this vertebra can only tell us this much. The victim had cervical spondylosis, and it was a bit serious... It's a pity it's not enough for screening."

Among modern people, who doesn't have a little cervical spondylosis?

However, reaching the level of hyperplasia at least indicates that the age is relatively high.

Wan Baoming said: "Perhaps we can set the age starting from 30?"

"That won't work." Yu Wenshu flatly rejected it: "I'm not afraid of a wider investigation range; what I'm most afraid of is missing something."

Jiang Yuan asked: "What aspects of the investigation are being done now?"

"One is missing persons, the other is furnaces; neither has results." Yu Wenshu sighed: "Now we can't even determine the victim."

If the victim were determined, perhaps the case could be solved through the victim's social relationships, just like the 513 case that was just solved.

If the special task force at the time hadn't been misled by the highly suspected random killing pattern and had changed the investigation direction, they could have originally dug out the killer through the deceased's interpersonal relationships.

Of course, regardless of which one, the difficulty is very high.

The case in front of us is the same; with just these few bone fragments, wanting to find the killer is almost certainly a process of looking for a needle in a haystack.

What Yu Wenshu is asking for is actually just to draw the area of the sea.

You can draw the sea area a bit larger, but it must be within the reach of human resources. Moreover, it must be within the reach of the Changyang City Criminal Police Detachment's human resources.

"I need to study it carefully for a few days. I can't give a conclusion right now." The answer Jiang Yuan gave was a bit beyond Yu Wenshu's expectations.

"Uh... with just these few pieces of bone, do you still need to study them for several days?" Yu Wenshu was a bit hesitant.

The previous forensic expert, Zhang Fengtian, actually only looked at them for a day or two. With so much stuff, if you look at it for a long time, can you really see flowers in it?

Jiang Yuan said: "It's precisely because there are very few bone fragments that the information that can be given is limited, and Forensic Expert Zhang has already reached most of the conclusions. The key now lies in how to crack the minute information to provide more information..."

Yu Wenshu nodded as he listened; put this way, Jiang Yuan's train of thought is really quite clear.

Jiang Yuan continued: "There are vertebrae and chest bones; logically speaking, it should be possible to determine age and height, and gender should also be determinable. But these bones were burned too severely; fundamentally, it's because the shrinkage rate is unknown, which led to Forensic Expert Zhang being unable to make inferences."

Jiang Yuan looked at Yu Wenshu and said: "After bones are burned, they will shrink. How much they shrink is a matter of the shrinkage rate. Currently, few people do research on shrinkage rates. A foreigner named Hermann has done it, proposing that the shrinkage rate of burned bones is between 8% and 14%, but he should have only done it up to 700 degrees. He didn't do higher temperatures, and no one else has done it either."

"With the shrinkage rate, we can calculate the original size of the fresh bone. Then we can infer height, age, and gender. But it's not very accurate either. It's best to create a regression equation directly from the burned bones..."

As Jiang Yuan spoke, his voice became slightly lower.

This work is quite tedious.

Yu Wenshu was even more stunned as he listened: "Then what should we do?"

"Can you apply for a corpse? The kind used for experiments?" Jiang Yuan asked.

Yu Wenshu spread his hands: "Not to mention that I haven't applied for one, this kind of scientific research project always takes a long time, right?"

"That's true." Jiang Yuan sighed and said: "Then should I estimate one?"

"Estimate one?"

"I can estimate a value, but this value is not guaranteed. Whether to use it or not, you can use it as a reference." Jiang Yuan had actually already obtained an estimate close to the correct one from the system, but for this thing, domestic and foreign research is indeed scarce, and everyone's estimated values are different. Which one to adopt and which one not to adopt are both problematic.

This is also because forensic anthropology is too difficult; it has only reached the lv3 level, and disagreements have already begun to appear.

It means that for this skill alone, the level of inheritance and development among forensic experts worldwide is not high.

As the conversation reached this point, the dozens of people in the conference room all heard that Jiang Yuan actually had ideas, but they weren't stable and carried risks.

And this kind of instability and risk is not just a matter of solving the case and funding; it will also involve the manpower used for screening later.

Letting hundreds, or even thousands, of people run themselves ragged for your estimate, only to find out the estimate is wrong—Jiang Yuan really cannot bear this kind of responsibility.

At the very least, Yu Wenshu has to make the final decision.

Yu Wenshu understood, thought for a moment, and decisively said: "Okay. You estimate it; now we can only treat a dead horse as a living horse. What is the conclusion?"

"I will give it to you by tomorrow at the earliest. I'll tell you after I finish calculating." As Jiang Yuan spoke, he hugged the evidence box, took a notebook, and went to the corner.