On the way from the provincial department to the deceased's house, Han Bo leaned against the car window to watch this city that he still felt strange despite being here several times.

The reason why I feel unfamiliar is not just because I can’t understand the language and cannot understand the local dialect.

This feeling is mainly caused by the terrain. A person who was born and raised in the Yangtze River Delta Plain only saw rockery in the park when he was a child. It is hard to imagine that there will be so many mountains here, and the entire city is actually built on the mountains.

Xinyang is located on the eastern slope of the Yunnan-Guizhou Plateau and belongs to the transition zone from eastern China to western Plateau.

The topography and landform trends are roughly east-west, with large undulations, high in the north and south, and low in the middle. The strange karst landforms are distributed in large quantities, including plateau mountains and hills, basins and river valleys, and terraces. The highest altitude is 1,762 meters, the lowest is 5o6 meters, and the average altitude of 1,071 meters in the urban area.

The city is surrounded by mountains and green forests.

The winding rivers in the city, green spaces surrounded by mountains and waters, and parks with different postures are scattered in front of you, with picturesque scenery. This may not be a first-tier city, but it is definitely a green city.

"Chief Han, I went back last night and thought about it all night. If Fu Liqin and Fu Liqing are not the murderers, then who could have done this? There must be a motive for murder and a reason for the murder. If the murderer has someone else, what will he do? What can he get if he kills Tan Xingtao's family?"

In the morning, Ge Zhengjian finally couldn't hold it in, and he held the steering wheel and couldn't help but analyze the case.

Han Bo recovered and asked back: "If anyone else can't get this vicious move, Fu Liqin, and Fu Liqing can get it? Don't forget that one of the deceased is Fu Liqin's biological daughter, Fu Liqing's niece. For the sake of custody of the child, they went to forensic doctors and sued. If the tiger is poisonous, how could they get it on the child?"

Just thinking about the grudge between the Fu family and the Tan family, I actually forgot that I still have a child.

Ge Zhengjian was asked and stammered: "Maybe, they may not know that their children are at home, or they may have considered this. Fu Liqing went there tonight just to pick them up and save them."

To solve a case, you must make bold assumptions and carefully verify them.

It can be said that during the investigation process, the case adopts the "presumption of guilt" and it cannot be like this when it enters the pre-trial process. The evidence must be strictly reviewed. If the case is transferred to the procuratorate to enter the review and prosecution stage, or if a public prosecution is filed with the court and enters the trial stage, the principle of "presumption of guilt" must be strictly followed to avoid causing unjust, false and wrong cases.

Although the young man was all speculation and there was no evidence, this assumption was not wrong. After all, the Fu brothers and sisters were indeed suspected of committing the crime.

Han Bo pondered for a moment and said lightly: "I think the breakthrough of this case should be based on the suspect's method of committing the crime, or where the deadly poison gas came from. As long as you can figure this out, the next work should be easier to do."

"Director Han, are you saying that the task force's investigation direction is wrong?"

"It's right, basic work is essential, but we are in a different position from them. We don't need to do these basic work in the early stages."

The task force is now collaborating with multiple police types, leveraging the advantages of "large corps" combat, spreading the net very much, and no matter which line progresses, the case will be successfully solved.

This is true in China, but foreign colleagues are actually similar.

Inferential analysis, one by one, one by one, solve one mystery after another, is a detective novel. If there is not enough resources and no large amount of manpower and financial resources, it will be useless to let Sherlock Holmes detect the case, even if it is just a not very complicated case.

Basic work and early work are very important. Ge Zhengjianshen agreed, thought about it and muttered: "How did the murderer get rid of the poison? How did the poison gas appear in his house?"

"So the comrades from the Xu task force who are going to the site also consider this and are investigating the site and visiting and inquiring."

...

As we were chatting, the car was approaching the community.

Knowing that the leader did not want to disturb too many people and did not want to panic among the residents of the community, Ge Zhengjian parked his car outside the community, locked the car door and walked into the community with Han Bo.

Han Bo guessed correctly, and the task force really wanted to figure out where the poison gas came from.

There were four police cars parked in the community. One policeman was busy asking an old man, and the others were probably in the building. The deceased's house was the easternmost part of the entire building. Two policemen were lying on the balcony to the east, studying the outdoor unit of the air conditioner.

"The air conditioner cannot only vent but not intake, otherwise it will be vacuumed. Dapeng, you have an air conditioner at home. Do you know where the air intake is? Is it possible for the murderer to use the air intake?"

“My home has air conditioning, but I only know how to use it.”

The two people above said Mandarin, one of them should not be a local in his hometown. Han Bo could hear it clearly and stopped in the southeast corner of the house. While observing the environment everywhere, he said: "There are air intakes for car air conditioners. Such air conditioners do not have special air intakes because the structure and principle are different."

There were many people who were urgently transferred to the task force at night, from several units.

The two above are not police officers from the branch office. They have never met Han Bo before. They don’t know that he is a deputy department-level investigator who came to guide the investigation by the Provincial Department’s Criminal Investigation Corps.

Han Bo is so young, Ge Zhengjian is even younger, thinking he is a colleague of the branch office.

One of the older policemen asked curiously: "Brother, what's the difference in the principle?"

The deceased had a good financial condition and decorated the garage downstairs very beautifully. Because the south-facing garage was renovated, it could no longer be used as a garage, so he parked an Audi sedan worth more than one million yuan at the entrance of the garage.

However, the car is still there, but the people are gone!

Han Bo looked up and turned his attention to the car again. While observing, he explained: "This kind of compressor air conditioner compresses gaseous freon into high-temperature and high-pressure liquid freon, and sends it to the condenser, that is, the outdoor unit dissipates heat and becomes a medium-temperature and medium-pressure liquid freon, so the outdoor unit blows out hot air.

The liquid Freon enters the steamer through the capillary tube, that is, the indoor unit. The space suddenly increases and the pressure decreases, and the liquid Freon will vaporize. From liquid to gas is a heat absorption process. It absorbs a lot of heat and the steamer will become cold. The fan of the indoor unit blows the air in the room through the steamer, so the indoor unit blows the cold air out of the indoor unit."

It sounds a bit reasonable. This kid really understands. Did he repair the air conditioner before becoming a policeman?

The two people above looked at each other and lay on the balcony window to listen carefully.

Han Bo looked up and pointed at a small tube they could see, and then said: "Water steam in the air will condense into water droplets when it encounters a cold steamer and flows out along the water pipe. This is why the air conditioner will emit water. Then the gaseous Freon returns to the compressor and continues to compress and continues to cycle.

In other words, the air inside is still blown, and the air outside is still blown, and there is no need for air intake. Of course, air conditioners now have air purification functions, which is the ventilation function, but most people rarely use this function."

The short policeman upstairs was very happy and reminded: "Brother, you are talking about cooling, we are talking about heating."

“It’s like heating.”

"How is heating the same? Isn't heating just to turn on the electric wire and blow hot air into it after heating?"

This is common sense, and they don’t even understand common sense.

It seems that the current education method is really problematic. Many things are only used without understanding the principles, and they will not repair them. Unlike Americans, if the car is broken, they repair it themselves, and if the appliance is broken, they will take a look. It is said that some Americans even have small machine tools at home, and all kinds of tools are as complete as auto repair shops.

Han Bo sighed inwardly and explained patiently: "Two, when this air conditioner is heated, there is a component called a four-way valve that allows Freon to flow in the opposite direction of the condenser and steamer when it is cooled, so when it is heated, it blows cold air outdoors and hot air indoors. In fact, it is used as the principle of liquefaction learned from our junior high school physics, that is, heat must be discharged when the gas changes from liquid to liquid, and vaporization, that is, the principle of absorbing heat when it changes from liquid to gas."

"There is no heating wire inside?"

"No, if you don't believe me, please take a look."

Xinyang City is cold in winter, but not as cold as Northeast China, nor as cold as Jiang Province.

This is a subtropical humid and mild climate, with no scorching heat in summer and no severe cold in winter, plenty of sunshine and abundant rainfall.

The air is not dry, there is no wind and sand all year round, and the annual average temperature is around 15.3. Among them, the hottest late July has an average temperature of 24; the coldest early January has an average temperature of 4.6. The pleasant climate is Xinyang and has won the reputation of "there is paradise above, Suzhou and Hangzhou below, and the pleasant climate is Guiyang."

It is precisely because summer is not particularly hot and winter is not particularly cold. Many families with good economic conditions do not install air conditioners. Even if they are installed, they are mostly tried several times when the hottest summer is, and they are generally not turned on in winter.

Han Bo noticed that the air conditioner plugs in several rooms were removed last night, and he couldn't help but add: "Even if there is an electric heating wire inside, or the deceased has used the ventilation function, it still needs to be powered. You can go in and check the plug to see if you can find the fingerprints or other traces left by the murderer when he pulled the plug out."

This kid not only knows how to repair the air conditioner, but also speaks quite impairedly.

The two people above thought this might be a major occurrence, but they made a big fuss. Thinking about it, they were a little dissatisfied, so they ran into the room and saw that the air conditioner plug was indeed pulled out, and there was a thin layer of dust on the plug, which obviously had not been used for a long time.

Ge Zhengjian almost burst into laughter. Seeing that the leader was interested in the deceased's car, he suppressed his laughter and looked up and shouted: "Brother, do you know where the car key is? We want to open it to take a look."

The policeman who seemed to be named Dapeng poked his head out again and said angrily: "In your Hou team, the Zhao team told me that it is not safe to park here, and I will drive back later."

"Where is Team Hou?"

"You should ask above. You don't know, but I don't know!"
Chapter completed!