Fast forward the video.

"Looking at the fishing line again, the fishing line used by the murderer was taken directly from the drawer of the TV cabinet in the living room."

The scissors used by the murderer were also taken out of the coffee table drawer.

"This shows that the murderer knew the Zhao Mingwei family very well, and it is very likely that an acquaintance committed the crime."

"The first group focuses on investigating the relatives of Zhao Mingwei's family, especially the whereabouts of Zhao Dezhi's adopted son, Zhao Danyang!"

Yes, according to the information, Zhao Dezhi has an adopted son in his family.

Zhao Danyang.

His current whereabouts are unknown and he is suspected of committing a major crime.

"The second group focused on investigating the packaging bags found in the trash can in Zhao's kitchen."

The packaging bag was discarded by the murderer midway.

It turned out to contain wax-sealed steaks and other items brought by the murderer.

From the perspective of the video, the murderer fixed his cell phone to his forehead and broadcast the entire process live from a first-person perspective.

However, the mobile phone and WeChat account used for the live broadcast belong to Zhao Mingwei himself.

"The font printed on the packaging bag comes from a supermarket called I Love My Family. The second team will do their best to trace the steak sales records of this supermarket."

"The third group, check the clothes on the deceased."

The clothes of the four victims fit very well. From the live video, it can be seen that the murderer took them out of his own bag.

The four pieces of clothing were made of very good material, neatly ironed, and obviously carefully organized.

Although the brand labels on the clothes have been removed by the murderer, judging from the fabric and tailoring, they are definitely brand-name clothes.

"The third group should focus on investigating the source of the clothes on the deceased, and try to find the purchaser and the purchase channel."

"In addition, collect the information of 32 people who watched the live broadcast."

"The fourth group focuses on investigating the knife and fork in Ding Suxi's hand."

Click!

The photo is projected to the screen again.

and gradually enlarged.

"The knife and fork in Ding Suxi's hand is not an ordinary Western-style knife and fork. Pay attention to the position of the handle of the knife and fork, which is printed with a special rose pattern."

"Ordinary low-quality knives and forks will not have such a clear printed steel pattern."

"The rose pattern is either the brand of cutlery or the unique logo of a certain Western restaurant."

"I want you to find out the origin of this knife and fork in the shortest possible time."

"At the same time, pay attention to the autopsy reports of the four corpses."

"The fifth team, investigate all the videos near Zhao Mingwei's home and try to identify people with suspicious behavior."

The house where four Zhao Mingwei and four others died was Zhao Dezhi's property.

Zhao Mingwei and Ding Suxi usually do not live here.

According to the information that Hulu City has found, Zhao Mingwei lives in the community next door.

Ding Suxi lives with her parents.

He did not live with Zhao Mingwei.

Judging from the situation at the scene, four people should have been poisoned by carbon monoxide due to a dinner party that afternoon.

After the general work arrangements were completed, only Qin Chuan and Chen Yan were left.

Who is Qin Chuan? He is an old detective.

Seeing Chen Yan's expression, you knew that Chen Yan still had some work to do.

"Chen Yan, do you still have any doubts?"

Chen Yan nodded: "There is another biggest doubt."

"This is the cause of death of these four people."

cause of death?

"You mean...why carbon monoxide poisoning?"

Chen Yan nodded.

It was really refreshing to talk about the case with such an old detective.

As soon as Chen Yan said it, Qin Chuan knew the key point that Chen Yan wanted to express.

"Team Qin, although the house where Zhao Dezhi lives is in an old community, carbon monoxide poisoning has not happened for how many years?"

Qin Chuan nodded.

In recent years, carbon monoxide poisoning has become rare.

In the past, due to economic constraints, some residents used charcoal or coal for heating.

Especially in winter, carbon monoxide poisoning is more likely and more likely.

However, now, especially in residential buildings in urban areas, central heating is used in winter, so there is basically no possibility of carbon monoxide poisoning.

Not to mention, it's summer now, August.

The weather in Hulu City is the hottest time of the year.

Where did the carbon monoxide come from?

Chen Yan checked Zhao Dezhi's home.

There are only two ways or possibilities to produce carbon monoxide.

Natural gas stoves and natural gas water heaters.

Many people may have misunderstandings about carbon monoxide poisoning.

It is believed that if the human body inhales too much natural gas or liquefied gas, it is carbon monoxide poisoning.

Actually this is not the case.

Whether it is natural gas or liquefied gas, its main components are hydrocarbons and alkane flammable gases.

After the human body inhales these gases, it will not produce symptoms of carbon monoxide poisoning.

Moreover, its fatality is far less serious than carbon monoxide poisoning.

Carbon monoxide poisoning can only be effectively treated in a hyperbaric oxygen chamber if detected early.

When other hydrocarbons and alkanes are inhaled into the human body, as long as they go to a well-ventilated place and breathe more fresh air, they will be fine.

Moreover, in order to prevent natural gas or liquefied gas from being accidentally inhaled by people after leakage, manufacturers will add irritating gases to the gas.

This is why the domestic natural gas and liquefied gas we use have a smell.

Carbon monoxide is produced after incomplete combustion of these hydrocarbons and alkanes.

When the combustion is complete, the gas produced is carbon dioxide.

"Generally speaking, when a natural gas stove burns, the flame is blue."

"I tested the stove in Zhao's kitchen. The ignition was normal and the flame appeared blue. There is basically no possibility of insufficient combustion."

"So, the possibility of carbon monoxide being produced by the stove is relatively small."

"The most likely thing to produce carbon monoxide is the water heater!"

Natural gas water heaters are different from stoves.

In order to heat the water as quickly as possible, after the natural gas water heater is ignited, the natural gas output will be large.

And because the space inside the water heater is small and the air circulation is not smooth, it is difficult to fully burn.

This is why natural gas water heaters have a special flue for exhaust gas.

"However, the normal exhaust power of a qualified natural gas water heater exhaust port is relatively large."

Chen Yan has been tested.

"Zhao's natural gas water heater exhausts smoke normally."

After turning on the hot water in the kitchen sink, Chen Yan went outside the building to observe.

The Zhao family is on the first floor, so it is very convenient to check.

"The smoke exhaust system is normal and there is no problem."

Smoke exhaust systems generally have protective covers.

After the protective cover is removed, there is a one-way opening and closing port.

It's just a prototype piece of iron.
To be continued...