Chapter 24: Starting From the Beginning
In the afternoon, after a little tidying up, Jiang Yuan and Wang Zhong, each riding their own electric bikes, came to the crime scene community.
The red brick building located in the suburbs is still quite contemporary. The two-way four-lane small road is planted with large trees of questionable species on both sides and in the middle. The sparse shrubs prove that the maintenance level nearby is very average, but the trees planted with time still maintain the basic quality of the residential area.
This is the far suburb of the county, but because there are some factories nearby, it is more prosperous than many places in the county.
Of course, it is only prosperous, not prosperous. Looking around, a piece of old residential area and new temporary buildings keep the environment at the level of old industrial areas.
Small shops are the mainstream business model nearby, and the facades of small shops are mostly old styles, which are difficult to arouse people's desire to consume.
And these shops that are too lazy to even clean up the door curtains also have no desire to install cameras.
Municipal construction here seems to have stagnated with time. The old road traffic is still well maintained, but it is only maintained to the level of the past, and newer or better things have almost not appeared.
The community where the crime occurred seems more desolate than other communities on the same road. Only at the main gate, there are a few old men gathered, looking at everything around with suspicion. The other two gates of the community are now handcuffed with big chains. These actions, which were originally convenience measures, are now regarded as the culprit.
"What are you doing?" Seeing Jiang Yuan and Wang Zhong riding an electric bike to enter the door, an old man bravely blocked the road with his body.
"Police." Both of them changed into plain clothes, so they took out their police IDs and took a look.
The old man frowned: "I heard that there are people who specialize in making fake police IDs to deceive people. Are you a liar..."
"Call 110 if you don't believe it." Wang Zhong said, and then said: "We are here to re-inspect the scene. Are you willing to be a witness?"
The old man took out his cell phone and was ready to call 110, but he was stunned when he heard it: "What?"
"Let's go in and take a look at the scene and see if there is any evidence. You just stand inside and watch, and then just sign it." Wang Zhong explained concisely.
China's criminal case scene investigation witness system requires the investigation agency to invite a third-party natural person to witness the crime scene investigation and inspection activities. This is completely different from the American judicial system that often appears in film and television dramas.
The United States adopts the police self-proof method, stipulates the on-site recording system, and requires the police to prove the fairness and standardization of the on-site investigation. In contrast, RB and Russia also adopt the on-site investigation witness system, but they are different.
Simply put, countries with a witness system require that the evidence collection of each case must be watched by outsiders in order to prevent the occurrence of false evidence as much as possible. In countries like the United States that do not have a witness system, each police officer is required to restrain himself. Once false evidence occurs, all cases handled by the police officer can be suspected.
Although there are often imperfections in practice, as a young policeman, Wang Zhong and Jiang Yuan both follow the regulations.
In fact, just finding one or two passers-by is still not in line with the spirit of the on-site investigation witness system. Fundamentally speaking, this system requires finding people who have a certain understanding of the scene, a certain understanding of criminal investigation and are not related to the case to be witnesses. If they can witness the investigation of the scene many times, it will be even better.
However, at the moment when the masses do not understand, witnesses have no financial compensation, the police are busy, and the judicial system is not demanding, such a requirement is obviously unrealistic, and the police are more willing to find obedient and sensible witnesses who do not hinder the investigation and will not leak intelligence.
Two old men who are not yet of retirement age but have started their retirement life early due to the decline of the company are good. It is also more compliant than using auxiliary police as witnesses.
The few old men at the door may be idle and hatching eggs, or they may be full of interest in the murder case in the community. After a long period of questioning, they reluctantly watched the two young men go to the building where the crime scene was located together.
Wang Zhong took the key from the office, opened the cordon, opened the door and went in, then locked it and changed clothes. The two old men who were not yet retired were asked to stand in the corner, not to talk, not to move, and not to take pictures.
"Where do we start?" Wang Zhong was not going to come, and he had no confidence to come for a re-investigation, but Jiang Yuan had an idea, so he followed him.
Jiang Yuan looked around and said slowly: "Let's start from the beginning."
As he spoke, the system slowly unfolded a translucent interface:
Mission: Start from the beginning
Mission content: Repeat the investigation of the scene of Xue Ming's case to obtain clues and evidence.
Jiang Yuan stared at the system interface for a few seconds until it disappeared.
"Start from the beginning?" Wang Zhong was a little dumbfounded, and then he leaned close to Jiang Yuan and whispered: "Is it necessary?"
"Try it." Jiang Yuan said, spread out his equipment, picked up a glass cup at the shoe cabinet at the door, dipped a cotton swab in water, and gently wiped it.
Although they had known each other for a period of time, his qualifications were a little deeper. But deep down, Wang Zhong believed in Jiang Yuan. For a skill like fingerprint, the difference in strength was too easy to show.
After standing there for a while, Jiang Yuan's actions made Wang Zhong speechless.
When ordinary surveyors wipe cups, or in other words, when surveyors in Ningtai County wipe cups, they directly use cotton swabs to wipe around the rim of the cup. Although this method can also wipe out possible DNA, it has always been just a simple method. Or, it is a common method with insufficient ability.
Jiang Yuan's wiping method is something Wang Zhong has only seen in very few cases. Jiang Yuan first dipped the cotton swab in water, then squeezed it until it was half dry. When wiping, he would not wipe a large area, but would choose a position on the rim of the cup, rub the cotton swab up and down, and wipe it evenly three to four times, trying to wipe out the possible DNA on it.
After wiping a point, Jiang Yuan would wait for a while and wipe a certain point again. This was repeated many times before the DNA extraction of a cup was completed.
Doing so would naturally take much more time than wiping around, but the probability of extracting DNA would also be much higher.
Although Wang Zhong had never tried Jiang Yuan's method of wiping DNA before, he knew from the details Jiang Yuan showed that Jiang Yuan's level was really higher than the team's current investigators.
For example, a semi-dry cotton swab is easier to transfer DNA than a dry cotton swab, and it is also easier to transfer DNA than a cotton swab soaked in water. As the saying goes, don't mix mud, don't get wet.
To use the way northerners understand it, a cotton swab is like a bath towel. Using a dry bath towel to rub dry skin will not rub off much stuff, and a bath towel soaked in water will only slide around and not rub off much dirt. You have to use a semi-dry bath towel to rub semi-dry skin. The effect is the best and you can rub off the most things.
Using the way that non-northerners understand, a cotton swab is like a tongue. If you wipe your tongue dry and lick dry skin, you won't be able to lick off much. If your tongue is saturated with water, the effect is not good either. You have to use a half-dry tongue to lick half-dry skin to achieve the best effect and the best friction.
Similarly, Jiang Yuan's method of wiping a specific point is much more effective than wiping around. Using the way that northerners understand, it's like rubbing a specific point with a bath towel and using a bath towel to saw. The amount of rubbed off cannot be measured in miles. Using the way that non-northerners understand, licking a point is more effective than licking everywhere.
Jiang Yuan really has something, so Wang Zhong doesn't talk too much. He just follows Jiang Yuan and helps him.
After working in the trace inspection position of the Criminal Division Squadron for several years, Wang Zhong has long understood that some things, when you see them, you feel that you understand them, or even understand them very well, but it does not mean that you can think of them, and thinking of them does not mean that you use them correctly, and using them correctly does not mean that you use them well, and using them well does not mean that you use them quickly.
Let's use an example that everyone who has participated in nine years of compulsory education can understand. Eury geometry has a total of 5 formulas, and Newton's three laws have a total of 100 words. Normal people can understand them after listening to the class, but when they see the questions, they may not think of which formula to use, and they may not use them correctly even if they think of them. Using them correctly does not necessarily mean that they use them well, and using them well does not necessarily mean that they use them quickly.
Wang Zhong also appears on the scene for investigation all year round. Seeing that Jiang Yuan can do it meticulously, well and quickly, he is simply surprised. Fortunately, when doing fingerprints, he is used to helping Jiang Yuan. After a while, he gradually became smooth, and even felt quite comfortable doing it.