Chapter 944

An Audi A6 with a Beijing A license plate, with a line of medium-sized buses, drove into the courtyard of the Changyang Municipal Criminal Investigation Detachment in a low-key manner.

Huang Qiangmin got off his A6 first, and then Jiang Yuan and others got off the medium-sized bus.

Speaking of which, the comfort level of the A6 during long-distance travel is not as good as the modified Coaster. It is not just that the comfort of the seats is not as good, but the posture of sitting tired in the Coaster, you can stand up and walk two steps, twist your butt and twist your waist, is something that even a sedan lengthened countless times cannot compare to.

However, the A6 has special significance for Huang Qiangmin, especially the A6 with a Beijing license plate, just like the LV old-flower worn on Huang Qiangmin, even if it is greasy, it is still trendy.

Yu Wenshu greeted Huang Qiangmin and Jiang Yuan and others with a smile on his face, and then smiled: "The trace evidence that Jiang Yuan wants to do, we have already worked overtime to do it here, and there is indeed a discovery. It is really a coincidence, hahahaha..."

"Can the source of the corpse be determined?" Jiang Yuan got off the car and moved his hands and feet, feeling quite surprised when he heard this.

Yu Wenshu waved his hand with a smile and said: "That's not the case. Ah, I said coincidence, because I remembered one thing. I don't know if you still remember, the first case we cooperated with at that time, Case 326 kidnapping and murder, which is the Tan Yong case, the one who dug a basement to imprison people, the first breakthrough at that time was proposed by Jiang Yuan, using the trace evidence method, and found a place to hide the corpse."

Yu Wenshu clapped his hands, put on an expression of recollection, and said: "I remember I said this at the time, Jiang Yuan used trace evidence to find a place to hide the corpse, it makes sense!"

"That is really a coincidence!" Jiang Yuan and Huang Qiangmin were stunned, and laughed twice in cooperation.

They basically remembered the case, and the logic and evidence of how to solve the case were things printed in their minds. But if you want to say what everyone said when they met, and can repeat the original words one by one, it must be said... listening to Yu Wenshu's retelling face to face is really a bit scary.

"This is the ability of photographic memory." Huang Qiangmin gave a real-name like.

Jiang Yuan also looked at Yu Wenshu up and down. It must be said that the feeling of this skill being in the hands of others is really uncomfortable.

"Our Yu Branch never loses when arguing with his wife." Wan Baoming, deputy director of the Changyang Municipal Criminal Science and Technology Center, had a technical atmosphere, and what he said made people not sure if he was complaining.

And he obviously knew Yu Wenshu's itchy spot. Yu Branch even waved his hand with a little pride and said: "My this doesn't count as anything, I just have a good memory for things, and I remember what I said when chatting with people a little more clearly. But if you ask me about the scene at that time, I can't remember it clearly, it can't compare to that kind of photographic memory."

"Is there also photographic memory? That is, remembering things like photos?" Liu Wenkai followed, mainly to show his face and get familiar.

Yu Wenshu nodded solemnly: "It's not uncommon... When I was studying, some people looked at the table in the book, and they could redraw it on the notebook with a brush. People like us can't do it, we can only look at it word by word, and after reading it, we have to understand it, so that we can draw the relationship diagram."

"So, when we took the exam that year, we were taking the exam with such students." Wan Baoming used a complaining tone to hold Yu Wenshu again.

Yu Wenshu laughed: "Now this kind of exam, we don't take any advantage, at most the liberal arts grades are better. You haven't seen that kind of science genius, look at the geometry figure, jump the answer directly, equivalent to, how to say... the answer comes out directly in their brains."

"This kind of person has no advantage when arguing with his wife." Huang Qiangmin laughed.

"The result is the same. Photographic memory, photographic memory, mathematical genius... all have to sleep on the sofa!" Yu Wenshu was full of vicissitudes.

"Win the argument, and still sleep on the sofa?" Liu Wenkai has a bit of lack of experience in this regard.

Yu Wenshu nodded solemnly: "Wait until you understand later. She can not argue, just point her hand and let you think about where you are wrong. To be honest, the memory is too good, it is really possible to remember the mistakes!"

Yu Wenshu was full of emotion, and looked at Liu Wenkai again, frowned, and said: "Wenkai, I remember he is 40 years old, right? Still so inexperienced?"

Liu Wenkai, who had just been promoted to deputy section-level like Wu Junhao, touched his forehead helplessly and said: "I... I might be better at coaxing..."

"How to coax?" The married men present all focused their eyes on Liu Wenkai.

Liu Wenkai: "I... I used to go to solicit prostitutes often... no, to catch prostitution, etc., and practiced some rhetoric, etc., and undercover, when I was working on the front line before, undercover, contacting special situations, etc., all need to coax people..."

"Right, I remember, the Changyang Municipal Public Security Detachment organized cross-regional prostitution catching before, and called you over once. You caught a first place at that time." Yu Wenshu's memory was awakened and quickly began to label Liu Wenkai.

Liu Wenkai hurriedly humbled: "Tied for first place. Men dressed as women don't count."

Yu Wenshu's memory was awakened for the second time, and he felt a bit uncomfortable: "Let's talk about our case... Baoming, you tell us."

Several people talked, and they had already entered the office. Yu Wenshu sat down, picked up the tea, and drank two sips lightly.

Wan Baoming is a criminal science expert in Changyang City, but he became famous 20 years ago. The technical iteration of these years cannot be said to be backward, it can only be said that he did not keep up, but a rough understanding is possible, and the overall situation is no problem, so he can only be a leader of the criminal science department and cannot be a technician anymore.

Wan Baoming cleared his throat, took a report from his arms, thought for a while, and then smiled: "Because we measured more points of trace evidence, the compounds measured were also more. I will say the conclusion directly. The fiber tissue taken from the corpse pieces has the same fiber structure as the woven bags found at the scene. They are all multi-layer bags, woven from polypropylene and polypropylene coated flat yarn. The warp density and weft density are relatively high, belonging to relatively good woven bags."

Wan Baoming: "The more special place is that we have determined that the killer used woven bags from three different manufacturers, one is green, and two are blue..."

Wan Baoming: "In addition, there are some textile fibers, which should come from the victim's clothing before death, including cashmere products and cotton textiles, which are natural fibers and relatively complex. Whether the manufacturer can be confirmed in the end is hard to say."

The inspection of trace evidence is relatively complex, or in other words, this thing is composed of a whole set of complex procedures.

First of all, there is no machine that can put trace evidence in and then produce results—just like other types of DNA testing, poison testing, etc.

Secondly, to test a piece of trace evidence, the inspection personnel need to classify it first, see if it is metal, plastic, or paint, rubber, glass, etc. It can be observed under a microscope, or it can be illuminated with an X-ray machine, or a small amount of trace can be taken as a solvent. In short, it must be subdivided before further testing can be done.

For example, if it is subdivided into fibers, then further analyze the characteristics of the fibers. Look at its color, composition, fiber morphology at the longitudinal and transverse interfaces, polarization characteristics, fluorescence characteristics, infrared spectroscopy, Raman spectroscopy, etc...

After doing these, it is time to classify. First, distinguish between natural and chemical fibers, and then see which natural or which chemical fiber it is.

If it is a natural fiber, it can be cotton, linen, silk, wool, etc... If it is a hemp again, it can be ramie, jute, green hemp, hemp, flax... If it is a hemp again, hey, then it returns to the hemp course, and then see which hemp it is...

And for the police, determining the type of fiber is far from the end, because what the fiber is used for also needs to be guessed and verified. If you want to use it to determine the source of the corpse in the end, you need to explore step by step from fiber to material, from material to manufacturer, from manufacturer to consumer.

After a circle, people are thin.

That is, there are woven bags at the scene, which can be directly compared, which is relatively simple.

But wanting to finally find the consumer through clothing, this difficulty is too high.

Jiang Yuan listened to Wan Baoming's introduction, reached out and asked for several reports to read, and after a while, said: "Simply put, the fibers suspected to be from clothing are not easy to determine the source... Then woven bags, what ideas do you have?"

Wan Baoming drank tea and said: "The types of fibers in trace evidence can all correspond to the woven bags found at the scene. At present, there are 6 different woven bags at the scene. And these woven bags are sourced from three different manufacturers. This is actually not very normal. At least it shows that the killer did not buy the woven bags at that time, but used inventory."

"So the killer or the victim's work, or the first scene, used woven bags?" Jiang Yuan translated Wan Baoming's words.

"At present, there is such a possibility... well."

"But the range is still a bit broad. The corpse pieces are determined to be the same person, right?"

"Two corpse pieces are too decayed, and no DNA was taken. Others have been confirmed to be the same person." Wan Baoming paused and added: "I will let people try again when I go back."

The latter sentence is purely for Jiang Yuan's face. Because you have used a national-level expert, your professionalism and meticulousness must at least be national-level. Otherwise, if the killer is caught in the future and it is found that there is a loophole here, it will be very shameful.

Jiang Yuan: "You can try more. Search around again. If you can find the skull, this case can at least be done with skull restoration, that is, the time spent is a bit long..."

Yu Wenshu responded: "The search range has been expanded, and the police dog brigade has also been supported."

"In this case, there is not much we can do." Jiang Yuan said difficult words, but his tone and expression were still positive, turned his head and said: "Let's do this, I will judge a relatively accurate time of death, let's go in two steps."

"Good."

"One is to find the monitoring nearby based on the time of death, and see if there is any harvest. If the other party uses an open truck or tricycle to transport the corpse, that would be the best."

Yu Wenshu smiled: "Don't say, there are quite a few similar cases."

Jiang Yuan used the only remaining EQ to smile, and then said: "Collect as much monitoring as possible. If there are any questions, I can further optimize it here."

Yu Wenshu: "Good!"

Jiang Yuan: "Second, scan the missing persons based on the time of death. I see that the DNA report is also out. If the victim is a female, you can expand the range slightly and see if any female missing persons in the whole province one week before death can match."

"No problem." Yu Wenshu felt Jiang Yuan's rare EQ and felt warmed. Because although the plan proposed by Jiang Yuan is simple, it can even be said to be a conventional criminal investigation idea, but there is a very core place here, which is to use a relatively accurate time of death as the dividing point.

Think about the subsequent investigation, the expenditure of personnel costs and case handling funds, all of which have to be unfolded based on this point. Ordinary forensic doctors dare not give a very specific time of death, and if they give it, they will give it very wide, but that loses its meaning.

It is only here in Jiang Yuan that Yu Wenshu can feel the heat of his youth, that kind of thick feeling of being protected and cared for, which inexplicably shrouded him.