Although Zhang Wang's gun-related case was not confirmed, the clues provided by Sun Tao can be regarded as meritorious service.
At the very least, a case of imitation gun reselling was solved.
It was very busy outside and the glue was not allowed to be opened, but it did not affect Lu Chuan in the laboratory at all.
Lu Chuan felt very comfortable being able to work on the case so quietly and wholeheartedly.
Letting go of everything and just focusing on the case in hand gave Lu Chuan a particularly reassuring sense of security.
However, the cost of enjoying this feeling is high-intensity work.
In fact, the detachment is cleaning up the backlog of cases every year. Even in normal times, there are people deliberately watching every backlog of cases.
For example, among the people in Ren Qiang’s group, almost everyone has one or two backlogged cases that they are following up on.
When there are no cases, I just follow the backlog of cases on my body.
Visit and investigate, look up information and so on.
In short, these cases are not ignored just because they are backlogged.
In addition, whether it is the detachment or the municipal bureau, sometimes they will also carry out special operations to clean up backlogged cases.
During a time when everyone is not too busy, concentrate superior forces to attack several backlogged cases.
Lu Chuan has now begun to clear out the backlog of cases from four years ago. This year, there is even less backlog of cases, just one.
Not every year there is a backlog of cases, and not every year there are major cases.
The Haizhou City Criminal Investigation Detachment’s backlog of cases was relatively large during the period 20 years ago.
Especially the backlog of murder cases, most of which are concentrated during that time period.
The reason is also very simple. The criminal investigation technology back then was very different from what it is now.
At that time, there was no such thing as DNA identification analysis, fingerprint identification had just started, and there was no so-called fingerprint database.
At that time, DNA identification analysis was only heard of abroad. In China, only the capital and a few economically developed provincial capitals had laboratories in this field.
Ordinary cases have no chance of involving such laboratories, and these laboratories are too busy just to handle major and important national cases.
Fingerprint identification is not like now, where it is directly entered into the system through a fingerprint scanner.
At that time, fingerprint cards were all used.
In those days, judging whether a criminal investigation detachment had combat effectiveness was based on who had accumulated more fingerprint cards.
Of course, at that time, the division of police types was not so detailed, and there was no such thing as front-line criminal police or active investigation.
According to Liu Guodong, when he was at work that year, the Haizhou City Criminal Investigation Detachment had more than 100,000 fingerprint cards.
What a concept, it can’t fit in a house.
At that time, fingerprint identification was to use these fingerprint cards to identify and compare, look at them one by one, and compare them one by one.
When he puts on his horse hoof glasses, he looks like an old elf.
In the case that Lu Chuan is currently solving, the deceased was named Wang Huifang, who was forty-six years old when she died.
When he was found, he died in the bedroom of his home. The cause of death was a stab wound in the abdomen and excessive bleeding.
The reporter is the husband of the deceased, named Zhang Chao, and they have no children.
The daughter-in-law dies and the husband calls the police. Anyone handling the case will focus their suspicion on the husband.
This is indeed what the criminal investigation detachment at that time did.
However, according to the file records, Zhang Chao was working in the unit at the time, and there were confessions from his colleagues.
There was no time to commit the crime.
In addition, according to the neighbors’ reactions, the two usually have a good relationship as husband and wife, and Zhang Chao’s motive for the murder does not seem to be sufficient.
Lu Chuan roughly browsed through the files and learned about the basic situation.
But this is not the focus of Lu Chuan. What he focuses on is the traces left by the murderer at the scene. The first is fingerprints.
The crime scene was at home. The deceased was killed on the bed in the bedroom. Fingerprints were everywhere in the room.
There are those from Zhang Chao, those from Wang Huifang, their parents, and even their neighbors.
However, after investigation, several situations at that time were basically denied.
There are also footprints. There were many footprints collected at that time. I compared them with relevant personnel, such as Zhang Chao, and determined that they were also left by acquaintances.
Judging from the traces at the scene, the murderer should be an acquaintance of Wang Huifang, and he is also someone who often comes in and out of her house.
Otherwise, if the murderer did not clean up the scene, there would be traces left.
So, who is the murderer?
Lu Chuan placed the current survey photos taken at that time on the table one by one.
Zhang Chao's house has two bedrooms, and the two usually sleep separately. Wang Huifang is in the master bedroom and Zhang Chao is in the second bedroom.
However, when Wang Huifang was killed, her body was in the second bedroom.
No murder weapon was found at the scene, and it was initially judged to be a sharp weapon such as a fruit knife.
After studying for a long time, Lu Chuan was looking for an entry point to start.
Fingerprints can be eliminated.
This scene was investigated by Liu Guodong, Lao Bai and Yang Sen. The fingerprint collection at that time should be said to be relatively thorough.
And the identification and analysis of these fingerprints have corresponding results.
However, because they were all fingerprints of acquaintances, these people would often enter Zhang Chao's home even if no case occurred.
Therefore, it is unrealistic to judge the murderer based on fingerprints without finding any strange fingerprints.
As for the footprints, although Liu Guodong and others are not particularly good at identifying and analyzing footprints, a simple comparison is still no problem.
The footprints can be compared with the footprints of these people. In other words, there are no footprints left by strangers at the scene.
These two clues are actually very important.
If a stranger committed the crime, he would have left footprints at the scene, even if he wore gloves and left no fingerprints.
But neither the stranger's fingerprints nor the stranger's footprints were found at the scene, which means that the murderer is one of these acquaintances.
Who is it?
The investigation of these people that year is recorded in detail in the file.
Unfortunately, everyone has an alibi.
The case reached a dead end at this point.
Wang Huifang’s sister, parents, brother, husband, parents-in-law, and several neighbors.
There are about ten people in total, and the murderer is most likely hiding among them.
Who is it?
Lu Chuan frowned. The identification and analysis of fingerprints can not only confirm the identity, but also determine the owner's recent diet through the oil and other ingredients attached to it.
But this thing has no way of identifying the order in which they were left at the scene.
Otherwise, as long as the order is known, the owner of the fingerprints that appears last will most likely be the murderer.
What to do?
Huh?
You can’t tell the order of fingerprints, but you can’t tell the order of footprints!
The room is only that big, and the footprints can be superimposed.
Lu Chuan dug out all the footprint photos, placed them on the table, and observed them carefully.
Sure enough, many of the footprints have superimposed marks, with one footprint covering another.
As long as these covered footprints can be peeled off, does the top covered footprint with the largest number belong to the murderer? (End of this chapter)