civil forensic

Chapter 273 Shrinkage

The burned bones are very different from the original fresh bones.

The first bone Jiang Yuan took out from the evidence box had been burnt to the point of porcelain, and the curvature of the bone surface had also disappeared. Moreover, there were several small bone fragments, many coal residues, and unknown Small nodules formed by dissolution of inorganic substances.

At first glance, this bone looks more like a strange handicraft, but if you look closely, you can see many details belonging to the bone.

As a forensic doctor, Jiang Yuan can see more. For example, this is a bone of a skull. The white color of the bone is made by burning at a high temperature of more than 1000 degrees...

The organic matter on the bones has also been burned away, which means that the commonly used DNA technology has failed.

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

The degree of burning of this bone is slightly lower, it looks like it has just been carbonized, not yet the degree of porcelain.

But still, all the organic matter was burned out, and the DNA method was useless at all.

When Jiang Yuan looked at the remaining dozen or so bones, they were all in the same condition.

The difficulty suddenly increased, which means that traditional DNA and other technologies are useless at all, and the only thing that can be relied on is the most traditional forensic anthropology.

On the plus side, many of the bones in burials, or Holocaust burial sites, are also of poor quality.

In terms of difficulty, traditional forensic anthropology has always been extremely difficult.

There are too many inconsistencies, too much experience, too many regression formulas, there are many things that can't be understood by normal reading, and even the author can't explain clearly.

It's like trying to describe the feeling of snot sticking to the back of the hand, and the feeling of tearing, and the feeling of rice, and the feeling of water shield soup, and the feeling of beef soup.

Although human beings have a rich vocabulary, it is basically impossible to accurately describe the sense of touch, or even correspond one-to-one.

These are the things that forensic anthropology confronts.

What does a fresh bone feel like, what does a burnt bone feel like, what is the difference between a skull and a facial bone, what is the difference between a finger bone and a phalanx...

Because forensic anthropology is faced with these seemingly simple and extremely detailed knowledge, without the hands-on guidance of the teacher, it will be very, very difficult.

As far as Jiang Yuan knew, there were two well-known old forensic doctors in Shannan Province, and they were often borrowed by ministries, provincial departments of other provinces, or traded out by the leaders of their own city or county bureaus.

If forensic medicine is scarce at the county level, then forensic anthropology is very scarce in the whole country and even in the whole world.

Mainly refers to well-made, two knives are not counted.

Jiang Yuan shook out the forensic report made by the forensic doctor in Changyang City and carefully reviewed it, and rated it in his heart. He estimated that this person's forensic anthropology ability was around LV2.8 to LV3.2.

The amount of knowledge reserves is about 320 Wang Zhong.

This is already a very strong forensic medicine.Jiang Yuan estimated that it should be made by TOP2 in Shannan Province.

Jiang Yuan turned over the top of the forensic report, and sure enough, he saw the name of the appraiser: Zhang Fengtian.

Jiang Yuan couldn't help saying: "Forensic doctor Zhang has already done the appraisal, so there is no need for me to read it again."

As he spoke, he picked up the bone and read it a second time.

Yu Wenshu saw Jiang Yuan's duplicity, and said: "Forensic doctor Zhang gave an appraisal report, but it only confirmed that it was a human skeleton. Gender, age, height are unknown, our main investigation direction now , is an incinerator that can reach over 1000 degrees, everyone has visited many places, and there is no clue..."

Although the burning of the corpse destroyed a lot of evidence, the process of burning the corpse actually created new clues.

For example, the method, technique, equipment, fuel, etc. of cremation are all problems.

Fully porcelained bones require a high temperature of more than 1000 degrees, and carbonization requires 800 degrees. From 800 degrees to 1000 degrees, it is just a hurdle, and ordinary civilian stoves cannot reach it.

Jiang Yuan listened and nodded: "There are only skulls, sternum and vertebrae here. It's really not easy to judge gender, age and height."

Yu Wenshu was a little disappointed, and turned to say: "The above coal lumps, or the hardened particles, have all been extracted by the trace laboratory, and there is no result for the time being."

He actually expected Jiang Yuan to play a role outside of forensic science.

After all, most of Jiang Yuan's ability to solve crimes is actually outside of forensic science.

Jiang Yuan roughly guessed a little bit of Yu Wenshu's mood, and didn't say anything or express it.

Solving a case is different from many things. It does not mean that you can do it according to the expectations of the leaders, or according to the imagination of most people.

The kind of detectives who I have an idea and are only short of a "CSI team" are still far from solving the case.

"Forensic doctor Zhang's forensic report is actually quite detailed. Nos. 5, 6, and 7 can be seen on the upper and lower sides of the cortical bone surrounding the cancellous bone structure. Slightly higher, it is judged to be vertebral fragments. Among them, there is an incomplete transverse process hole on the posterolateral side of the No. 6 vertebral body, which is judged to be cervical vertebrae, and labial edge hyperplasia can be seen..."

Jiang Yuan commented, and then said: "Let me see, this vertebrae can also see such things. The victim has cervical spondylosis, and it is a little serious... It's a pity that it is not enough for screening."

Modern people, who have no cervical spondylosis.

However, to the extent of hyperplasia, at least it shows that the age is relatively old.

Wan Baoming said, "Maybe we can set the age to 30?"

"That won't work." Yu Wenshu resolutely vetoed it: "I'm not afraid of the scope of the investigation being too large. The most fearful thing is that it will be missed again."

Jiang Yuan asked: "What kind of investigation are you doing now?"

"One is the missing persons, the other is the incinerator, and there is no result." Yu Wenshu sighed: "Now there is no way to even determine the victim."

If the victim is identified, maybe the case can be solved through the victim's social relationship, just like the 513 case that was just solved.

If the task force at that time hadn't been confused by the highly suspicious pattern of random killings and changed the detection direction, it would have been able to dig out the murderer through the deceased's interpersonal relationship.

Of course, no matter what, the difficulty is very great.

The case in front of me is the same. It is just such a few bone fragments. To find the murderer, it is almost certainly a process of finding a needle in a haystack.

What Yu Wenshu asked was actually nothing more than the area of ​​the sea area.

It is possible to draw the sea area a little bigger, but it has to be to the extent that manpower can achieve.Moreover, it must be to the extent that the manpower of the Criminal Police Detachment of Changyang City can reach.

"I have to study hard for a few days. I can't come up with a conclusion now." Jiang Yuan's answer was a bit beyond Yu Wenshu's expectations.

"Uh... just a few bones, do you still need to study for several days?" Yu Wenshu hesitated.

The former forensic doctor Zhang Fengtian actually only looked at it for a day or two. There were only so many things. After looking at it for a long time, could it be possible to see the flowers?

Jiang Yuandao: "Because there are very few bone fragments, the information that can be given is limited, and most of the conclusions have already been drawn by forensic doctor Zhang. The key now is how to decipher the tiny information, so as to give more accurate results. Lots of information..."

Yu Wenshu nodded his head. In this way, Jiang Yuan's train of thought is really quite clear.

Jiang Yuan continued: "There are vertebrae and sternum. Logically speaking, the age and height should be able to be judged, and the gender should also be able to be judged. But this bone is too burnt. In the final analysis, the shrinkage rate is actually unknown. As a result, forensic doctor Zhang was unable to make inferences."

Jiang Yuan looked at Yu Wen's book and said: "Bones will shrink after being burned. How much shrinkage is a matter of shrinkage rate. At present, relatively few people have done research on shrinkage rate. There is a foreigner named Herman who has done it. , proposed that the shrinkage rate of the burnt bone is between 8% and 14%, but he should have achieved 700 degrees, and he did not do it at a higher temperature, nor did others."

"With the shrinkage rate, the original size of the fresh bone can be calculated. Then the height, age and gender can be inferred. But it is not very accurate. It is best to do the regression equation directly from the burnt bone..."

As Jiang Yuan spoke, his voice became slightly softer.

This work is quite tedious.

Yu Wenshu was even a little dumbfounded: "Then what should we do?"

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

Yu Wenshu spread his hands: "Don't say I haven't applied, this kind of scientific research project will take a long time."

"It's true." Jiang Yuan sighed and said, "Then I guess one?"

"Estimate one?"

"I can estimate a value, but this value is not safe. You can use it for reference." Jiang Yuan has actually obtained a close to correct estimate from the system, but there are really few domestic and foreign researches on this thing. Everyone The estimated values ​​​​are different, which one to use and which one not to use, there are problems.

This is also because forensic anthropology is too difficult, and differences have already begun to appear at the level of LV3.

That is to say, in terms of this skill alone, the level of inheritance and development of forensic doctors all over the world is not high.

At this point in the conversation, dozens of people in the conference room could tell that Jiang Yuan actually had an idea, but it was risky if he was not sure.

And this kind of uncertainty and risk is not only a problem of solving the case and funding, but also involves the manpower used in the follow-up investigation.

Let at least hundreds of people, as many as thousands of people, break your legs for your estimate, and the estimate is wrong. Jiang Yuan really can't bear this kind of responsibility.

At least Yu Wenshu had to make a decision.

Yu Wenshu understood, thought for a while, and said decisively: "Okay. You can guess, now you can only treat a dead horse as a living horse doctor. What is the conclusion?"

"I'll give it to you tomorrow at the earliest. I'll tell you after I finish the calculation." Jiang Yuan said, holding the evidence box, took a notebook, and went to the corner.

(End of this chapter)