Police Detective

In line with the principle of not destroying evidence, he brought the computer into the conference room, cleared a large table, and Wang Liang quickly disassembled the entire display screen.

A dozen years ago, being able to assemble a computer was a technical job, and you could get paid once you assemble it. Now, basically everyone can play with computers. But that doesn’t mean everyone can take the display apart and examine it.

Most people have never taken apart a display.

Wang Liang spent more than half an hour disassembling the display screen very carefully, removing all the removable wires.

"This display screen has only been dismantled once. It was dismantled by Wang Huadong a few days ago. There are only traces of disassembly once." Wang Liang finally said.

"Can you see this?" Wang Huadong came closer, obviously distrustful of Wang Liang's traceology skills.

"Basically anyone who sells mobile phones can tell whether there are traces of disassembly on the phone. Many of your screws only have traces of the current one, and they are the same screwdriver. Who else could it be if it weren't you?" Wang Liang finally confirmed: "This Can you just pretend it, it’s not worth investigating."

"Okay." Bai Song nodded and said expressionlessly, "Let's check the main chassis."

Bai Song had already noticed that Wang Liang's dismantling was much more thorough than Wang Huadong's. Wang Huadong just opened it, removed the big parts, and then took a closer look to see if there were any special structures. That was it.

At this time, the large round table in the conference room was already full of people.

Everyone is here. These people who are staying in the hotel are here on a business trip just for this case. I heard about this and must come to see the excitement.

"The main chassis has been dismantled many times." Wang Liang said: "Memory modules have also been added, but this is normal. This is an assembly machine. I guess I bought a new one after playing with it for several years and running out of memory."

"This is normal. Be careful of the dust and dismantle it slowly." Bai Song said.

"Inspector Bai, what can be discovered here?" Captain Wang here asked: "What problems can there be here?"

"I'm not sure either." Bai Song frowned and watched Wang Liang dismantle the computer.

"Take the CPU out and let me take a look." Bai Song said.

"What are you doing to dismantle this? Aren't you dismantling the memory?" Wang Liang asked curiously.

"Demolish it." Bai Song didn't say much.

"Okay." Wang Liang found it very happy to have someone ordering him.

When he has no clue when handling a case, he almost collapses. But being able to come up with clues and arrange useful work makes Wang Liang feel more energetic at work. Over the past few years, Wang Liang has become accustomed to listening to Bai Song when handling cases.

There is a fan outside the CPU, and a very crude heat sink underneath, which can be removed to reveal the CPU. The heat sink of a good computer is made of copper core, which is probably aluminum.

It was full of dirt, and Wang Huadong didn't clean it at all. It's not that Wang Huadong is lazy, but the previous disassembly was done in the room where the computer was kept, so there is no need to clean up the dirt.

The CPU is dirty and greasy. It looks disgusting. It has probably not been cleaned for at least four or five years.

"Is this normal?" Bai Song asked.

"It's normal. Everything in this broken computer is normal. It's normal for a few D hairs to be wrapped around the fan." Wang Liang said, feeling a little sick himself: "I installed it."

"Unplug the CPU," Bai Song continued.

"This thing fits tightly. If there is any missing thing, the computer won't be able to turn on." Wang Liang continued, fearing that Bai Song wouldn't believe it.

Seeing that Bai Song was unmoved, Wang Liang could only gently take out the CPU. With this simple action, more than a dozen people leaned over to look.

"Look, there's nothing." Wang Liang raised the CPU.

Nothing is normal. If something as sophisticated as the CPU can be plugged in between the motherboard and the motherboard and the computer can still run normally, then if you have this technology, you might as well build a photolithography machine by hand.

"What's that? Bai Song pointed to a white line under the CPU slot." This white line is very, very thin. If it weren't for the darkness around it, you wouldn't be able to see it at all.

As soon as Bai Song said these words, everyone stood up and gathered around.

Wang Huadong immediately took out a magnifying glass and came over. Wang Liang quickly got out of the way.

You can see from the magnifying glass that there is a little bit of white powder seeping into the edge of the CPU. If you don't look carefully, you can't really see clearly.

There is too much dirt and dust in here. When the computer is powered on, the CPU fan keeps spinning, and there is still hot air here. Basically everything is blown away, but there is still some left in this gap.

"Huadong, do you still remember the aluminum alloy doors and windows in Yao Xin's case?" Bai Song asked.

Wang Huadong felt like he was struck by lightning!

yes!

Many traces of the scene will be destroyed.

In the Yao Xin case, due to the fire and fire extinguishing, 99% of the evidence at the scene was destroyed. Only a little remnant of styrofoam was found in the two tightly fitting aluminum alloy doors and windows, which became the key evidence to solve the case.

In this case, everyone originally felt very calm, and there was no possibility of the evidence being lost, but they never thought that the computer that was turned on was actually the best way to continuously destroy the evidence.

The deceased was discovered several hours after his death, but the computer had been running.

On a microscopic level, a high-temperature CPU and fan are no less than a fire or a flood.

"What is this white powder?" someone asked.

"Could it be cyanide?"

"Then why don't you open the window quickly and don't get so close."

"Fuck, this is too scary." Someone immediately wanted to open the window.

"Don't move!" Bai Song shouted to the policeman who was about to open the window: "Cyanide decomposes quickly in the air, how can it be stored for such a long time?"

Bai Song's words seemed to have a magical power, and everyone immediately stopped being anxious. Someone asked directly: "Inspector Bai, what is this?"

"This needs final testing." Bai Song saw everyone's expressions of disappointment: "However, there is a high probability that this thing is sodium formate."

"What?"

"What is sodium formate?"

"It's baking soda, soda ash."

"That's sodium formate."

"Oh oh oh, how come there is this"

Bai Song ignored the others and asked Wang Liang: "Based on your experience, what temperature can the CPU of this broken computer reach when running those legendary games?"

"Generally, when the CPU is running games, the temperature will not exceed 55 degrees Celsius, but this computer cannot dissipate heat well, not the CPU, nor the motherboard. It is estimated that it can reach more than 70 degrees Celsius." Wang Liang estimated.

"Yes." Bai Song looked at everyone: "Of course, this could also be potassium formate, etc. Actually, this matter is not that troublesome. What I want to say is that the murderer relied on this CPU to kill."

"Inspector Bai, you mean that the murderer put the cyanide here?" Detachment Zhao asked: "If that's the case, when was it put in? If it was put in fifteen days before the crime, then what? Can cyanide last that long?”

"Originally it's not possible, but wax-sealed sodium cyanide can." Bai Song said in surprise: "Many substances that can react with air will be stored in paraffin or kerosene. Many things in our daily life can also be used at home. After the candle is melted, seal it. If you take a small amount of sodium cyanide, seal it with wax, and put it between the CPU and the fan, there will be no problems on weekdays. But when Xiao comes back to turn on the computer to play games, and the CPU heats up, the problem That's huge! You know, household candles will soften when they are above 40 degrees, and simply melt at 70 or 80 degrees. Under this fan, the melted paraffin has long been blown away and fused with dust into a greasy state. And cyanide Sodium will naturally hydrolyze in humid air to form hydrogen cyanide, and it can decompose quickly above 60 degrees Celsius."

"It's possible!" Wang Liang was a little excited: "In that case, the murderer entered this house fifteen days in advance, put the wax-sealed sodium cyanide here, and then waited for Xiao himself Activate the death button!"

Thinking of this, Wang Liang looked at the power button with some trembling and murmured: "I didn't expect this to be the death button."

Wang Huadong was speechless looking at Wang Liang's second grade look, and looked at Bai Song: "Why is there left sodium formate?"

"When sodium cyanide meets water and carbon dioxide in humid air, it can produce sodium formate, hydrogen cyanide and other substances. Hydrogen cyanide is highly toxic. Several milligrams per cubic meter are dangerous to the human body. It is still humid above 60 degrees. In such an environment, the concentration of hydrogen cyanide will quickly reach a lethal level. Sodium formate will not continue to decompose at this temperature, so these things should be the remaining potassium formate. The rest were blown around by the fan and mixed with dust. ." Bai Song explained: "This is the method of killing."

"Inspector Bai, I think you seem confident. If you have anything else to say, please tell me." A superior expert looked at Bai Song and said with some interest.

"Hello, Mr. Sun." Bai Song greeted this person first, and then said: "For now, I think the murderer may be one of the people who stole the electric vehicle battery."

When Bai Song said this conjecture, no one had any surprised expressions, which meant that a few people were a little more confused. Because at the beginning, many people thought about this issue, but there was no other evidence to support it.

"I'll continue." Bai Song cleared his throat: "The reason why we didn't find this when we checked the families where the batteries were stolen is probably because this family didn't call the police. In recent years, except for some people who don't care about electric vehicle batteries, other people If you don't call the police, you probably don't trust the police. Why should I say that this person did it? Because there are several relatively good conditions for committing the crime.

First, Xiao lost one of his keys. As a new thief, he probably dropped it while stealing and was picked up by the owner. Second, the police visited many communities and asked if they had any questions. No electric vehicle battery was stolen and the suspect has been arrested. Therefore, the person who lost the electric car also learned who stole the electric car. There is not much place nearby. If you ask anyone, you may know that Xiao Mou was detained; thirdly, the police went to Xiao Mou If the murderer wants to know where Xiao's home is, he can find it by following the police. The police station is handling a theft case and won't care about anything else at all. If someone follows him secretly, he probably won't notice. "

"This doesn't make sense. Why don't you trust the police? Since the person who lost the electric car already knows that the police caught the thief, why don't you call the police?" someone asked.

"This is almost inevitable. For a person who can commit murder, and such a sophisticated behavior, there is a high probability that this person himself has a big problem. For example, if he is a murderer on the run, it is impossible to take the initiative to contact him. Police. I wonder if everyone can agree with this reverse explanation?" Bai Song looked at everyone, and then said: "If he committed the crime and could make such a case, the traces and other traces could also be cleaned up. After fifteen days Xiao Xiao When someone goes back, he will definitely close the door and play on the computer, and then he is basically dead."

"Then why did Xiao run out?" Zhao detachment asked.

"This is a miscalculation of the murderer." Bai Song explained: "The murderer originally thought that Xiao would be poisoned quickly and then die at home. According to Xiao's otaku nature, no one would know until the body smelled bad. Once seven days have passed, After eight days, everything in the house was covered up, and the hydrogen cyanide was long gone. If the computer had been running for seven or eight days, it is estimated that even this sodium formate would not have been discovered. And in the highly decayed scene, our focus may be on the corpse. It's winter and it might even take more than ten days before it's discovered.

After Xiao developed very uncomfortable feelings such as chest tightness and shortness of breath, he felt something was wrong. Then he ran out and went up the corridor, where he fell and never got up again. He died of acute cyanide poisoning. In this way, the door is open, so even if there is hydrogen cyanide gas, it will quickly disperse. By the time someone discovers him in the corridor, a few hours later, the hydrogen cyanide gas will be gone from the scene. "

Detachment Zhao nodded with satisfaction and arranged for people to collect the milligram-level white powder and arrange for people to conduct testing overnight tonight.

"Why would you kill someone for a trivial matter? I really can't figure it out." someone asked.

"Tonight's suicide case was actually because of a trivial matter." Bai Song said: "I don't know if you have ever experienced a difficult time. Sometimes when you are having a difficult time, someone provokes you, and you even want to expose him. God will kill each other. We don't show it here. In some areas, some murders really stem from the phrase 'what are you looking at'."

"Yes, what Detective Bai said makes sense. We don't know what the murderer was doing at the time, but he probably valued the electric car very much or was delayed because of something urgent. In addition, what Detective Bai said, the murderer may be a fugitive himself. The murderer or something was so angry that he designed such a scene. This does not require any advanced knowledge of chemistry, just a clever enough design." The superior expert nodded affirmatively: "I think this idea is very reasonable. Now since we have so many people, we might as well check how many households in these communities have people who have lost batteries without reporting the crime."

"Okay!" All the teams were gearing up.

This posture has a feeling of red and blue fighting against each other.

(This one cup is worth two cups. Today’s 10,000-word update is OK)