Concubine

Chapter 313 Tool Traces (asking for a monthly ticket at the last minute)

"The iron chain is bound here." Yang Qiuchi pointed to the bottom of the column, and made a chopping motion with the hatchet, and said, "If it were you, you would use this hatchet to cut off the iron chain. How would you cut it?"

Song Yun'er took the hatchet and looked at the pillar: "Of course I used this pillar as a pad, and pressed the iron chain on the pillar to chop at an angle."

"Judging from this cut, it was cut with a knife. If you cut it according to your method, there will definitely be cut marks on the post, at least there will be indentations left on the wood of the post by the iron chain being cut by the hatchet. But If you look carefully, there are only left and right friction marks on the post, which are left by the dog pulling the iron chain when the dog is tied, but there are no marks or indentations of the hatchet."

Song Yuner took a closer look: "It's just not there." After thinking for a while, she said, "It must have been chopped on the ground."

"Take a good look at the shape of this hatchet, especially the pointed tip that bends down at the front. You can try it. Can you cut off the iron chain lying on the ground?"

Song Yun'er compared and smiled: "I can't cut it, the elbow in front is supporting it, and the blade of the hatchet can't cut the iron chain on the ground." After thinking about it, she said again: "However, you can find a piece of wood to use as a pad Let’s go, can’t we?”

"Then look around, is there any wood to use as dunnage?"

Song Yun'er looked around, the yard was neat and tidy, and she didn't see any wood used as dunnage.

Yang Qiuchi said again: "Besides, isn't this upright post the best plywood? Wouldn't it be much more convenient if this person chopped off the thin iron chain with a hatchet directly on the upright?"

"That's right, there's no backing, and there's no cut mark on the post, so it seems that this man didn't use a hatchet to cut it. Then, what did he use to cut it?"

"It's probably an axe, so I'm going to focus on the axe." Yang Qiuchi stood up, walked back to the pile of hatchets and axes, and ordered the Yamen arresters to take the axes back. Put it in Su Lizheng's house for safekeeping, and return it to the villagers after the matter is clarified.Afterwards, he returned to Bazhou City with a team of people.

Although the machete can initially rule out the hatchet, only the ax is left, but there are dozens of axes brought back by the police. There is no way but to test them one by one to see if they can find the chopped iron. chain axe.

To find out which ax cut the iron chain, it is necessary to carry out trace identification.

The axes used by ordinary people are generally cast in the same mold in the blacksmith shop, so the new axes do not have obvious individual characteristics, but after a period of use, they will be cut and polished continuously Form their own different knife-edge features.

The blades of the machetes look similar to the naked eye, and they are all very sharp. As long as they are often polished, there will be no obvious curling. However, if you observe the blades with a microscope, you can find that the blades are uneven. , It is precisely because of this characteristic that when a knife cuts an object, it will leave scratches on the section that are difficult to distinguish with the naked eye.

In appearance, these scratches are very similar to the barcodes in supermarkets. However, the naked eye is usually unable to distinguish them, nor can they be seen. They must be seen with a microscope.The scratches on the cross-section of the object cut by the machete are the same as human fingerprints. They are very different, and no two cross-sectional scratches that are exactly the same can be found.

Of course, such scratches are still different from human fingerprints.Because a person's fingerprints will not change for life, even if the fingerprints are cut off with a knife, destroyed with sulfuric acid, or even this layer of skin is peeled off.The fingerprints on the newly grown skin are still exactly the same as your original ones, and the characteristics of the fingerprints will not change in any way.

The scratches on the cut section are different. As long as the chopping tool has been polished or used frequently, the original features on the knife edge will gradually disappear and change. Therefore, the scratches on the section extracted by the criminal investigation department, if within six months I can't find this machete. Under normal circumstances, this information can basically be thrown away.

This case happened just two days ago, so after analyzing and comparing the scratches on the cut section, we can find the chopping tool that formed the cut section.

What Yang Qiuchi had to do was to cut something with the suspected machete (usually a relatively soft aluminum rod, so that it is not easy to damage the characteristics of the edge of the machete), and after forming the cut marks, he would connect with the iron extracted from the neck of the deceased. Comparing the superimposed images of the scratches on the chain section, if the features can be clearly overlapped and a reasonable explanation can be given for the non-overlapping parts, it can be concluded that the fractured material was cut off by the suspected cutter.

To perform such trace comparisons, a microscope must be relied upon.The microscope that Yang Qiuchi brought across is a charge-coupled microscope, which can be connected to a computer, and the images seen can be transferred to the computer for comparison and processing.

However, the blade of the ax has a certain length, and it is necessary to find the part of the blade that cuts the iron chain, and conduct a cutting and sampling test to have comparative value.

The chemical composition of the iron chain is definitely different from that of the axe, especially the steel part of the blade of the axe. Since the interaction of objects is mutual, the ax will cut off the iron chain, and scratches will be formed on the fracture of the iron chain. The iron chain will also react on the axe, not only causing the edge of the ax to curl, but also frictionally adhering part of the iron filings of the iron chain to both sides of the axe edge.

The simplest example to explain this phenomenon is to cut off a person's limbs with an axe, and blood will adhere to the axe.Or chopping a crayon with a knife will rub the color of the crayon on both sides of the blade.

However, when chopping iron chains with an axe, since iron chains generally do not decolorize, the traces of friction and layering formed on both sides of the ax blade are generally invisible to the naked eye. How to find them?
In modern society, it is very simple. Check the chemical composition of the adhesive on the blade of each ax and compare it with the chemical composition of the broken iron chain, and you will soon be able to find out which ax was cut off. This iron chain, and can accurately determine which specific part of the ax blade cut off the iron chain.

If further confirmation is needed, this part can be used to cut the aluminum rod to form cutting marks and compare it with the fracture. As long as the extraction is in time, the same determination can generally be made.Even if it takes a long time and the characteristics of the ax blade have been destroyed, the same determination can be made based on the fact that the chemical composition of the blade's adhesion is the same as that of the iron chain fracture.

This is very simple in the modern forensic evidence inspection with chemical inspection conditions. However, the forensic evidence inspection equipment brought by Yang Qiuchi this time does not have chemical inspection equipment, because chemical inspection depends on the substance to be inspected. Inspection equipment is also very different, and it is impossible to exhaust and it is not necessary to build one.

Yang Qiuchi didn't have chemical composition testing equipment in his hand, so there was no way to use this method for testing.Can only find other alternatives.

In what way?The most urgent task at the moment is to find the part where the ax cuts the iron chain, and then conduct a simulation test to form the trace of the cut section, and then perform a contrast superimposed image test, and finally find out which ax formed the fracture.

Although the iron chain is very thin, only as thick as a silver hairpin, the iron is still relatively hard, and the hardness of steel in the Ming Dynasty is obviously not as good as that of modern times. Therefore, if you use an ax to cut the iron chain, the edge of the ax may be It will curl or crack, and now we can only do a simulated chopping test for each axe.

Aluminum rods are generally used for this kind of test, but it was difficult to find such things in the Ming Dynasty. Yang Qiuchi could only find a few thicker copper wires. The hardness of copper is much softer than that of iron, so it is not easy to damage the ax Knife-edge features.

First check the edge of each ax to find the curled and chipped parts, use this part to chop and cut the thick copper wire, then use a microscope connected to a laptop to observe and extract the cross-sectional image, and then make traces with the cross-sectional image of the iron chain Overlay comparison.

There are dozens of axes, each of which has three or five curls or cracks. In total, there are hundreds of axes to be inspected, which is really cumbersome. However, forensic inspection is inherently boring and cumbersome. After a long time, it can even be boring.But Yang Qiuchi was used to it.

I was busy until dark, and only checked for a little while.Meanwhile, the person sent to the grandma's house of Huo Xiaosi's child to verify the situation came back and said that Huo Xiaosi's family was indeed there the day before yesterday and had never left. Relatives and neighbors can testify.

Huo Xiaosi's family had no time to commit the crime. It seemed that they could only continue to look for clues of the machete from the broken marks.

Hongling came to ask Yang Qiuchi to have a bowl of rice, he ate it in a hurry and then ran back to continue testing.

Song Yuner asked him how the test was going, but he was only vague.None of the previous inspections found the same or similar traces of cutting and scratching on the broken iron chain, and I did all afternoon's useless work.

Song Qing felt sorry for him, and told him not to work so hard, rest well, and continue working tomorrow.

How could Yang Qiuchi not know the truth that revolutionary work can never be finished, and besides, it is not considered revolutionary work now.However, that's the way he is, once the work starts, he doesn't like to stop halfway.

So, after a quick meal, he went back to the forensic room to continue testing.

Until late at night, I was dizzy, and only half of the inspection was done. The table was already piled up with short sections of copper wire for inspection, but I still couldn't find it.

Song Yuner came several times, Yang Qiuchi's forensic room was forbidden for anyone to enter, and the door was locked from the inside. Song Yuner called a few times, saying she wanted to come in to accompany her, but Yang Qiuchi still didn't open the door.

Finally, the power of the laptop ran out, and Yang Qiuchi was dumbfounded. He couldn't detect it, so he could only wait for the sun to come out the next day, charge it with a solar battery, and then continue the test.

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PS: The battle is at its last moment, and the Kangxi Braided Army surpassed the Third Young Army and rushed to my position!
The forward position is already at stake, and the cold light on the shiny saber of the braided army can be seen!
How to do?How to do? !

The soldiers of the Concubine Legion are fighting bloody battles, and the bright red battle flag of the Concubine Legion is still flying high on the No. [-] position!
However, the enemy has rushed up!
It's time to test the concubine warrior!Fight!Brave concubines, bayonets!Blow the charge!Hand-to-hand combat has begun! !For victory, go! ! ! (To be continued, if you want to know what happens next, please visit www.CMFU.COM, more chapters, support the author, support genuine reading!)
(End of this chapter)