The difficulty in solving the case of a nameless corpse is mainly due to the fact that the identity of the victim is not known, his social relations cannot be investigated, and the causal relationship that may be related to the case cannot be analyzed. In the absence of clues such as witnesses and on-site evidence, the pen "Fun" Pavilion www.biquge.info makes people scratch their heads and don't know where to start.

12.26 The identity of the victim in the case is clear, the scene of the crime, the scene of the body dumping are clear, and there is even the murder weapon left by the suspect after committing the crime.

The bloody handprints and DNA of the suspect that may exist cannot be escaped from the murder weapon, and the top priority at the moment is to determine the direction of the investigation, find out the causal relationship that may be related to the case, and lock down the suspect, at least to delineate the general scope of the suspect. Otherwise, even if the bloody handprints and DNA of the murderer are successfully extracted, the murderer may not be brought to justice.

After all, the public security organs have just begun to establish a fingerprint database and a DAN database of ex-offenders, which will take a long time and require a lot of manpower and financial resources to complete the collection of basic information. If the murderer has no criminal record and does not commit another crime after committing the crime, then it is useless to have a database.

Confused, the more I think about it, the more confused I become.

Han Bo rubbed his temples and raised his head suddenly: "Xiao Xu, you sort out the case from beginning to end, and let's sort out our thoughts together." If there is any omission in the combing process, Lao Tian added. Political commissar, Su Da, if you have any questions, you can ask them at any time. ”

"Yes. ”

Xu Bing walked to the white blackboard, picked up the pen and began to comb it. After reading the materials for four days, the time, place, and characters are very clear, and you don't need to look at the notes.

"At about 4:38 a.m. on December 26, 1990, Duan Qinglan, a sanitation worker in the port area, found a female corpse in the garbage bin when cleaning the section of Huafeng Packaging Factory on Changgang South Road. Since it was not dawn and there were no passing vehicles and pedestrians on the road, she ran all the way to the Changgang Road Police Station. ”

"Xiao Xu, wait, I have a question. ”

"Commissar, excuse me. ”

"Did the sanitation workers dump garbage into the bins, or did they find Xunli's body when they were about to clean up the garbage in the bins?"

It turned out that the idea of sorting out the facts of the case was good, and the lesbians were thoughtful and thought of a question at the beginning. Han Bo knew what she really wanted to ask, and didn't want to ruin this brainstorming method of analysis, so he held his chin and listened attentively.

"The garbage found when dumping garbage into the garbage bin, as for the garbage in the garbage bin, the male sanitation worker with the garbage truck is responsible for cleaning it up. Shovels are used to shovel the car, the carriage is quite high, and the female comrades cannot do this work, they are mainly responsible for cleaning the road. ”

Zhou Suying was very strange and asked, "Where is the first scene?"

Xu Bing took out a map from his desk, hung it on the white blackboard, and pointed to the location where the indicator had been marked: "Here, about 280 meters away from the garbage can." ”

"Where's the bike?"

"In the dead grass on the east side of the road, it is 6.3 meters away from the first scene. ”

Although Zhou Suying is not a criminal policeman, although she has never really participated in the investigation of a case, she has seen many criminal suspects, and all of them are mentally ill, which is more dangerous than ordinary suspects.

At this moment, she is not the insider just now, but a policeman, she got up and walked to Xiao Xu's side, pointed to the photo of the corpse on the white blackboard and said: "The murderer stabbed Xunli several times, and it can be seen from the clothes how much blood has flowed, the first scene is on the road, so far away from the scene of the corpse, there will be no less blood on the ground." The sanitation worker dumped garbage into the garbage bin, indicating that she had cleaned the road, how could she not find blood stains after cleaning, and if she found blood stains, why did she not suspect it?"

I have never been a criminal police officer, I have never seen a bloody scene, and it is normal to ask such questions.

Xu Bing put down his pen and explained: "Report to Political Commissar Zhou, after a certain period of time, the color of the blood flowing out of the human body will gradually change from bright red to dark red, reddish-brown to gray. The forensic doctor speculated that the time of the victim's death was about 9 to 10:30 in the evening of the 26th, which means that the blood was not only dry but also discolored.

It was dark when the sanitation workers were sweeping the road, and it was difficult to tell if it was blood or other stains under the dim streetlights. At that time, the police who made the record worked meticulously and asked the same question, and the materials showed that she really didn't pay attention at that time, and the broom swept all the way over. ”

She was the first to find the body and also inadvertently destroyed the scene. ”

Tian Guogang became addicted to smoking, for fear of choking the two leaders who did not smoke, walked to the window and nodded, turned around and said: "The broom splashed around with small coagulated blood clots, and it can be found within 280 meters when investigating the scene, so we can't determine whether the murderer carried the body and threw it into the garbage can, or used transportation." ”

Putting the body on a bicycle would drip blood, and putting it on a tricycle would also bleed, and by means of transport he was obviously referring to a car, in other words, they were suspicious of the people attending the banquet.

That's right, how can such a big suspicion not be checked, at most the scruples will not appear on the material.

Han Bo decided to wait a while and ask them how they checked at that time, Zhou Suying didn't expect this, and asked a very uncommon sense question, feeling a little shameless, and returned to his seat and motioned for Xu Bing to continue.

After receiving the alarm, the Changgang Road Police Station immediately sent police to protect the scene and reported to the sub-bureau at the same time. At 5:24 a.m., the Wei detachment, then deputy director of the criminal investigation bureau of the port branch, led the police to the scene.

At 7:17, the forensic doctor of the city bureau arrived at the scene and investigated with the technical police of the sub-bureau. At around 8 o'clock, an employee who lived in the dormitory of the Port Authority and worked in the No. 2 Hong Kong Cotton Factory recognized the victim when he passed by the scene to watch the excitement......

The city leaders were furious and ordered the city bureau to be responsible for the investigation of the case, and the then director of the bureau personally served as the head of the special case team, and the deputy director of the criminal investigation bureau of the municipal bureau, the head of the criminal investigation detachment, the director of the sub-bureau, and the deputy director of the criminal investigation bureau were all members of the special case team. At that time, it was divided into three groups, the first group was responsible for investigating the social relations of the victim and the victim's husband, the second group was responsible for probing, and the third group was responsible for investigating the social relations of the victim before he came to Nangang. ”

Xiao Xu paused, and then said: "The second group is personally responsible for the deputy director of criminal investigation of the Municipal Bureau, and this group is divided into several groups, the first group is responsible for investigating all adult men within 3 kilometers of the crime scene, the second group is responsible for finding out all the ex-convicts in the urban area, the third group visits and inquires about the city's hotels, the fourth team investigates all the ships that dock and leave the port before and after the crime, and the fifth team investigates the city's foreign population.

Almost all that can be taken into account has been taken into account, and almost all the police forces that can be mobilized in the urban area have been pressed on this case, and in the course of the large-scale investigation, more than 100 large and small cases have been destroyed, and more than 200 suspects of various crimes have been arrested, so that many citizens think that they will start to crack down on ...... again."

Although Nangang was one of the first batch of coastal open cities, compared with several open cities in Dongguang, the economic development rate was not fast, and there were not many foreign populations at that time.

Since it was Christmas in Western countries at the time of the incident, there were no foreign ships docking here, and there were only a few domestic freighters at several terminals. The passenger terminal is in the Yangtze River area, not in the port area where the crime scene is located, and there are no passenger ships docking in the middle of the night, even if they come from the passenger terminal, they are not close.

It is very likely that a local, or at least a resident of the local community, committed the crime, but it has not been investigated.

The more than 100 photos on the two walls are all people who were thought to be a little suspicious at the time.

This suspicion does not mean that they are more likely to commit crimes, but that they have criminal records or are usually idle, there is no alibi on the night of the crime, or the alibi provided cannot be confirmed, at least 90% of the more than 100 people do not know the victim, and there is no intersection between work and life circles at all.

Finding out the bottom of the queue and sitting in the court for interrogation, that's how the case was handled at that time.

Han Bo walked to the corner of the wall and squatted down, listening to Xiao Xu sort out the case while looking through the victim's relics.

After Xiao Xu finished speaking, Lao Tian added.

He looked back at Han Bo and said in a low voice: "There is no progress in the investigation, and the social relationship between the victim and his wife has not been investigated, and we propose that the people who participated in the wedding should be investigated, involving so many city leaders, and the bureau leaders did not agree or clearly object, so the Wei detachment organized us to investigate from the side."

Ask who was at the wedding first, and then ask how they got home, and if you take a car or ride a bicycle with relatives and friends, it is equivalent to having an alibi, which can basically rule out suspicion. If you can't inquire about it, or if you go back, it will be used as a key investigation. ”

"Old Handsome" did not disappoint, Han Bo secretly praised one.

Zhou Suying felt incredible, and couldn't help asking: "Lao Tian, so you also checked me back then?"

"Nope. ”

Political commissar of the technical investigation detachment, the highest-ranking female cadre in the city's public security system.

Don't say that you didn't check her, even if you did, you can't say it, Tian Guogang hurriedly explained: "The murderer stabbed the victim four times, and stabbed it through several layers of clothes, the movements were clean and neat, the woman was not so strong, we only investigated the adult man in secret, and even secretly checked the leader's car, but found nothing." ”

"And then?"

"Later, it was discovered, and it was found when investigating a driver, and I couldn't implicate the leader, so I took the initiative to admit my mistake, and the result was still implicated. ”

The case has not been solved, and the leader of the secret investigation is actually carried out!

Investigating the city leaders is not a trivial matter, and Han Bo finally figured out why the then bureau leader stepped down.

The reason why "Lao Shuai" was able to become the leader of the criminal police detachment was entirely because his rank was not high enough at that time, and his subordinates helped him to cover up, and the city leaders who were on fire did not notice him, otherwise he would probably be in a police station now.

No wonder no one has mentioned this case for a long time, it turns out that there are so many hidden secrets.

Han Bo was full of emotion, and just when he didn't know what to say, Su Haibing raised his head and said: "Han detachment, in the past ten years, we can only find the old comrades of the Second Hong Kong Cotton Factory and the Yangtze River District Cultural Bureau to understand the situation. The victim had to go to the victim's school to check on her classmates and find a few classmates who could be contacted to find out how she was doing during her college and high school years. ”

"That's what I thought, too. ”

"When will the dagger be tested, if fingerprints and DNA can be detected, we will at least have a bottom in our hearts for the next investigation. ”

If it cannot be detected, it means that there is no evidence, and even if the subsequent investigation discovers a causal relationship that was not previously discovered, the suspect cannot be brought to justice if he is successfully locked.

He didn't want to do useless work, and Han Bo didn't want to either.

After years of practice and research, trace inspection technicians have summed up many effective methods, but there are generally problems such as the scope of application is not wide enough, the handprint lines are easy to diffuse and destroy, and the dark objects show that the handprints are disturbed by the background and the contrast is weak.

Since years ago, I began to study how to make the fingerprints that may exist on the tip of the dagger visible, read a lot of literature, consulted several experts in the appearance of blood handprints, there are several ways, the key is that we can only succeed and not fail, and we must be able to remedy it in time after the failure of the manifestation as the premise.

To this end, I went to the Red Cross to buy a bag of blood, prepared a dozen samples on the metal with fingerprints, ordered several reagents according to the test plan, and waited for the metal to corrode for a while before conducting the test. ”

"Wait?"

Han Bo nodded and explained: "The old blood handprint, the peroxidase in the blood is inactive and cannot participate in the reaction, but the iron ions on the hemoporphyrin ring in the hemoglobin molecule can act as a catalyst, which can make the hydrogen peroxide release the primary ecological oxygen, oxidize the colorless tetramethylbenzidine into tetramethylbenzidine blue, and show a blue-green blood handprint."

Similar to last year, it took a few days to extract the DNA from the detonator, and it was not possible until the peroxidase in the blood of the test sample became inactive. If the test is successful, the color contrast is obvious, the lines are coherent, and it is easy to take pictures, or the test failure can be remedied by a second plan, I will go to the murder weapon to be examined. ”

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PS: Thank you again for the generous tip from the wolves vs book friends! (To be continued.) )