Attending ex-girlfriend's wedding, arresting the groom's officer on the spot

Chapter 202 Bone Age Analysis
The demolition of the bridge pier is done by explosion-free demolition. Under the impact of the explosion-free hammer, the cement block debris on the bridge pier varies from large to small.

The steel bars twisted and wrapped around the fragile white bones.

Perhaps because the blasting at the beginning was too intense, the exposed left hand bone was partially broken and incomplete.

Lu Chuan has been observing for a while.

"Mr. Zhang, you should dig out the bones from the concrete pier first." Lu Chuan pointed to the nearby pier: "When the Qin team reported just now, they said that there were also bones on the concrete pier next to them."

"On the other hand, let's see if we can first collect DNA information through the fragments of the bones to determine the identity of the deceased."

Lu Chuan has experience in bone identification and analysis, and has been affirmed by Zhang Yuanchao.

Zhang Yuanchao nodded: "Well, let's collect some bone fragments first, and do some technical experiments first. The survey and forensic doctors in QZ City will have to work hard to clean up the bones as quickly as possible."

The case is more important, mainly because the number of skeletons found so far is relatively large.

However, for the specific investigation situation, it is still necessary to first see whether the identity of the skeleton can be confirmed.

"Collect some of the remaining clothing fragments."

Lu Chuan made another request.

The case has a great impact, but it is different from the investigation of ordinary cases.

The cleaning of the bones is very time-consuming.

Normal violent demolition is impossible, otherwise, the bones cleaned up will be slag.

Of course, it is impossible to use a hammer to tap a little bit. If it is done like that, it may not be finished in more than ten days.

Li Donglin from the Provincial Department personally supervised the work, and Qin Hui, the captain of the QZ City Criminal Investigation Detachment, went on stage in person, with the help of firefighters, and began to cut the bridge piers bit by bit.

The current survey office of QZ City.

The identification and analysis of the bones required special instruments, and the QZ City Criminal Investigation Detachment did not have relevant instruments, so they had to send them back to the provincial department for processing.

But Zhang Yuanchao did not leave. Li Changgeng and the others could handle technical matters. As long as they sent the results, Zhang Yuanchao could analyze the necessary elements based on the results.

Lu Chuan was responsible for the investigation of the clothes fragments of the deceased collected at the scene.

"There's blood!"

This is Lu Chuan's biggest discovery.

The clothes have been in the pier for at least 15 years. Because the cement blocks oxygen, it has not oxidized and is in a relatively good state of preservation.

After at least 15 years of storage, it is no longer possible for the blood to be red.

But the existence of bloodstains will not disappear with the passage of time.

Even, in many crime scenes, the surface is clean with only water washing, and there is no red bloodstain. However, using some on-site investigation methods, bloodstains can still be found relatively easily.

However, such bloodstains cannot obtain information such as DNA.

Zhang Yuanchao, as the head of the technical criminal police, summed up all the clues.

The technical identification data of the bones have not yet come out, and Lu Chuan's discovery is the only discovery.

"Can I do a blood type test?"

"Let me try." Lu Chuan's intermediate field survey skills have technical reserves in this area, and it is not a big problem to deal with it: "The clothes fragments are relatively small, and it may not be possible to extract a sufficient amount of surface antigens."

"It's okay. Since there are bloodstains, we may be able to collect them when we dig more fragments at the scene."

Technical appraisal does not only rely on instruments, many things can be analyzed from the surface of the skeleton.

On the dissecting table, there were three left hand skeletons.

"Lu Chuan, what can you tell from the bones of these two left hands?"

The three left hands exposed on the pier, the arm part is still in the pier, but the left hand has been cleaned out.

It's just that it's more severely broken, and there are some missing pieces when put together, and some of them are covered with cement fragments.

Since five years ago, Zhang Yuanchao has seldom conducted forensic examinations in person, but guided and followed him to learn from the younger generation.

Therefore, Zhang Yuanchao mostly uses the method of asking questions to guide.

The forensic doctor Wang Ruiqing of the QZ City Criminal Investigation Detachment was still at the scene, and the people who followed Zhang Yuanchao came from the provincial department.

The metacarpal bone is a relatively special bone component of the human body.

Whether it is the palm or the sole of the foot, it is the part with the largest number of bones. In comparison, the metacarpal bones are more valuable in forensic analysis than the metacarpal bones.

One of the most important is the judgment of bone age.

The degree of development of the ossification center between the phalanges of the metacarpal, the carpus, and the radius and ulna is a very important basis for determining bone age.

It just so happened that the metacarpal bones of the three left hands were severely broken, but the integrity was not bad.

The thickness of the ossification center can be better observed.

Of course, theoretical knowledge is theory, and all the forensic doctors present are aware of this, but the extent to which the ossification center is developed and the age associated with it are only brought about by experience.

"From the perspective of size, the bones of the two left hands are wide, and the gap between the phalanges is relatively large. It is more likely that they are male."

In general, male bones are wider than female bones, especially the hand bones.

The three left hand bones on the dissecting table are very contrasting, and even the size of the two left hands is wider than Lu Chuan's own hand bones.

The growth of bones has a certain proportional relationship.

Just like tall people, the size of shoes will also be larger.

In reality, it is rare to see people who are 1.8 meters tall and wear shoes in their thirties.

Therefore, Lu Chuan gave this judgment first.

However, he only said that the possibility is greater, not absolute.

Strictly speaking, hand bones cannot be used to identify the sex of skeletons.

At least, it cannot be used as evidence in judicial identification.

Because in reality, there are many cases where men and women are of the same height, and their hand bones are also about the same size.

And there are not a few tall women, so hand bones and foot bones cannot be used as judicial identification standards for judging gender.

"Age...Suspected woman's metacarpal bone, ossification center analysis...should be between 30 and 40 years old."

"The bone age of the other two metacarpals... between 25 and 35 years old."

The age difference given by Lu Chuan is between ten years old.

After hearing this, everyone looked at Zhang Yuanchao in unison.

There are not many skeleton cases, and there are not many opportunities for everyone to accumulate experience.

Judging age by hand bones...

Those who can judge the young, middle-aged, and old people are masters.

As a result, Lu Chuan was able to delineate to within the range of ten years old.

real or fake?

As a result, Zhang Yuanchao nodded affirmatively, and the smile on his face was called satisfaction.

"Not bad, not bad, can judge so accurately."

"Leaving aside the judgment of gender, Lu Chuan's judgment of bone age is very accurate, please see here..."

Zhang Yuanchao's level of identification and analysis of the skeleton was higher than that of Lu Chuan.

What Lu Chuan mastered was the intermediate level of bone identification and analysis skills, while Zhang Yuanchao's level was at least advanced, or even higher.

"It depends on the development degree of the ossification center of the hand bone and the size of the phalanx. Specifically, I have summarized a set of empirical formulas in this regard..."

Zhang Yuanchao's theory and experience were not included in Lu Chuan's skill card, so he listened very seriously.

Using Zhang Yuanchao's method, the age range of the deceased was narrowed down to five years old.

The appraisal and analysis on Lu Chuan's side continued, and the work on site became more busy.

The first bridge pier initially confirmed to have four skeletons has been completely smashed, and the four skeletons have been completely excavated.

The excavation of the second pier is gradually coming to an end.

Finally, all excavation work was finally completed in the early hours of the next day.

(End of this chapter)