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

Luminol reagent is the most commonly used blood identification product for criminal investigation on-site investigation.

The proteins contained in the blood cannot be washed away with ordinary water.

At the same time, the large amount of iron ions contained in it cannot eliminate traces through simple cleaning. Luminol reagent can reduce blood stains into fluorescent traces through chemical reactions.

Of course, the luminol reagent will produce a chemical reaction with all blood, and it cannot be determined that it is human blood through the luminol reagent test.

Therefore, in blood identification, after confirming the presence of blood, the type of blood will also be determined.

Even if the scene is like this, there is a high probability that it is the traces left by human blood. After all, no one can kill chickens and fish to cause this phenomenon.

But after returning to the current investigation laboratory, Lu Chuan and others still had to identify and analyze the type of blood.

Of course, based on the current situation at the scene, it can be determined that it is human blood.

The identification is only a necessary judicial procedure and does not affect the subsequent steps and speculations of the current investigation.

Lu Chuan waved his hand and made a circle, which meant that the bathroom was not the scene where the body was dismembered, but the scene where the murderer disposed of the dismembered body.

"The murderer probably washed away some broken body parts through the sewer here."

"The fat debris found in the sewer and the organ fragments blocked the sewer, so half of the finger was left."

In the living room, Yang Sen was collecting fingerprints.

It is daytime, and the UV fingerprint light is not very efficient at detecting fingerprints, but it can distinguish whether there are fingerprints.

After confirming the fingerprints, Yang Sen collected the fingerprints through the powder method.

Lao Bai collected some hair from the bed in the bedroom.

According to the information provided by the landlord, the room was only rented to Yang Qianqian.

Therefore, the traces of life left here should belong to Yang Qianqian.

After the collection is returned, the DNA extracted from the hair and fingers can be compared to determine whether the deceased is Yang Qianqian.

While the current survey side was carrying out its work in an orderly manner, the second operation team began to visit the neighbors.

"There is a girl living next to us. She is pretty and very tall, but she doesn't socialize with us very much. She has been here for...two or three years."

"Have you ever seen anyone come next door?"

The house Yang Qianqian rents is a 2-stairs, 3-unit apartment. Her room is in the middle. In addition to her room, there are two neighbors on the left and right.

There is no one in room 601 on the right, and the property management team is in contact.

A family of five lives in room 603 on the left, and the hostess's parents are at home.

Zhang Hui was questioning the two people.

"I didn't pay much attention to this. The girl next door gets up late in the morning. She usually doesn't get up until the afternoon, but she also comes back late at night."

"We usually go to bed when the girl comes back, so we don't pay much attention."

"But the girl is quite polite. We meet her sometimes on weekends and she often says hello to us."

"Have you found any suspicious persons in the past few days?"

"No... the security in our community is pretty good, and the security guards are on patrol."

"It seems that no strangers were found in and out of the building."

"But this city is different from the countryside. Everyone doesn't know each other very well. Only some of us know each other by face."

"Have you heard anything in the past few days?"

"movement?"

"There's nothing going on here... Oh... By the way, their family seems to be making dumplings a lot in the past few days."

"Oh? How does Auntie know that their family makes dumplings?"

"There is the sound of the meat grinder, buzzing and buzzing all the time..."

The kitchen of the room where the crime occurred.

Liu Guodong found a meat grinder in the closet.

"Xiao Lu, come here."

Although the meat grinder was quite clean, Lu Chuan still discovered some details. “There were blood stains on the blade and handle.”

After that, I sprayed the luminol reagent...

The entire meat grinder glowed fluorescently.

Liu Guodong sighed: "Put it away."

Then, the two conducted a detailed inspection of the kitchen.

"Master, there is blood splattering here!"

There were blood stains sprayed at high speed on the kitchen wall, and there were blood stains on the display window.

It's just that the other party cleaned it up very carefully and wiped it all off.

But under the cupboard, there were still blood stains that had not been cleaned up.

"this!"

Then, Lu Chuan found a bloody ax in the gap behind the refrigerator.

The entire wooden handle of the ax head was dark red, and there were fine bone residues where it was connected to the ax head.

"Is this a dismemberment tool?"

Liu Guodong nodded, picked up the axe, and looked at it. There were already slight curls and small gaps on the blade surface.

"newly bought."

However, on the rear section of the wooden handle of the axe, you can clearly see the fresh wood texture, which is light yellow in color. It is obvious that it was just purchased.

After putting the ax into the evidence bag, the two continued their investigation.

After a while, a package of curly black plastic was found inside the cupboard.

After Lu Chuan took it out, the nauseating smell of blood suddenly came out.

After unfolding the black plastic, there were still some undried blood stains on it, possibly because the plastic had been curled up and not evaporated.

A chopping board stained with brown blood was also found under the cupboard.

There are obvious marks of ax chops on it.

"The murderer should have put the body on a plastic sheet, placed it on a chopping board, and used an ax to dismember it."

"Then a meat grinder was used to crush the flesh and blood, and it was washed away in the sewer."

Liu Guodong nodded and agreed with Lu Chuan's analysis. The murderer obviously did not want to hide these things.

"But one thing, where are the bones?"

Liu Guodong pointed to the meat grinder next to him: "This thing can break down the minced meat, but it is impossible to cut all the bones into pieces and then flush them away in the sewer."

Human bones are much harder than most people imagine.

The specific data is difficult to describe, but if the hardness of steel is compared to 9, then the hardness of human bones is between 4 and 5.

Harder parts such as teeth and skulls may have a hardness of 6 or 7.

Liu Guodong has handled several corpse dismemberment cases before, but in no case did he find that the murderer could use any convenient equipment to finely chop human bones.

Of course Lu Chuan also knew this.

Compared with Liu Guodong, he has the skills of skeletal identification and knows more about human skeleton.

However, there is more than just physical methods to wear down human bones.

It is sometimes easier to wear away human bones using some chemical methods.

In terms of chemical composition, the main component of human bones is calcium carbonate.

Soaking bones in acidic substances can soften them in a short period of time.

Then some physical methods can be used to break the bones into fine pieces.

However, in several cases that Lu Chuan had experienced, the murderer had not been found to have used this method, and no suspected chemical substances were found at the crime scene. (End of chapter)