Diary of a Criminal Investigator

While Lu Chuan was conducting the crime scene investigation and analysis, the forensic doctor was also performing an autopsy on the body.

The conclusion reached at the scene by Lu Chuan was not much different: the fatal injury was the mark on the neck; a rupture of the carotid artery led to massive blood loss, ultimately causing death by shock.

The carotid arteries are located on either side of the trachea and are the most easily perceptible arteries in the human body.

By placing a hand over either side of the throat, one can clearly feel the pulse of the carotid arteries.

The bleeding from an arterial injury is very different from a venous injury; when an artery is injured, the blood gushes rather than flows.

When the carotid artery is traumatized, the blood can spray up to three meters.

However, an injury to the carotid artery does not cause instant death; the bleeding process can last from 3 to 15 minutes.

During this process, the victim remains conscious and experiences symptoms such as weakness, fatigue, chills, and dizziness.

In comparison to injuries to other arteries, treating a carotid artery injury is more difficult and has a higher likelihood of being fatal.

Especially if both carotid arteries are injured, these changes are almost irreversible.

For other arterial injuries, applying immense pressure to compress the vessel can potentially stop the arterial bleeding.

However, employing this method for a carotid artery injury would undoubtedly accelerate the victim’s death.

This is because the carotid arteries supply blood to the brain, and once compressed, the lack of blood flow to the brain would quickly lead to death due to oxygen deprivation.

One of the victim’s carotid arteries was completely severed, while the other was two-thirds severed.

The middle portion of the trachea was completely cut, with only a few strands still connected.

From the forensic physician’s perspective, the killer’s strike was precise and ruthless.

The angle was tricky, the force immense, a single cut to the throat.

The estimated time of death aligned with Lu Chuan’s conclusion, at 1:30 a.m. the previous night.

While the crime scene investigation and the forensic team were busy, the major crimes unit and the Binzhou City Criminal Investigation Team were equally engaged.

The victim’s identity was confirmed: Zhao Kai, male, 38, ran a building materials business at the Northern Market.

The person who reported the crime was his wife, Li Guifen.

"Li Guifen and Zhao Kai got married before the New Year in February this year. Both of them were previously married."

During the day, Gao Xiang had already arranged for people to investigate the victim’s family situation.

"We immediately contacted Li Guifen’s workplace and confirmed that she was on duty at the railway section from 8:30 a.m. on the day before the crime, the 22nd, until 8:30 a.m. on the day of the incident."

"The victim’s time of death was at 1:30 a.m. on the 23rd, so it’s confirmed that Li Guifen had no opportunity to commit the crime."

As Li Donglin listened to the report, his pen continuously scribbled notes in his notebook.

Gao Xiang continued with the report: "And judging by the method the victim was killed at the scene, and the nail at the top of the head, the killer is the same as in the three serial murders since March 16."

Though three serial murders had occurred, the police had not disclosed any details.

How the killer murdered, what weapon was used, and the nail in the head—none of these details were revealed publicly.

If someone were to copycat the crime, the likelihood is almost non-existent.

This assessment was also accepted by the major crimes team.

"Is there any connection between Zhao Kai and the previous three victims?"

Gao Xiang shook his head: "We checked the call records and bank transfer records between the first three victims and Zhao Kai during the day, but found nothing."

"What about social media chats?"

"Also nothing, we checked them all. These people seemingly did not know each other."

The relationship between the three from the previous incidents was also a major investigative focus for Gao Xiang’s team, but a week had gone by with little progress.

Li Donglin pondered for a moment and then looked at Wang Song: "How about your side?"

In the morning, while Lu Chuan and his team were investigating the scene, Wang Song, Song Mingguang, Luo Qiang, and their team began their inquiries.

Wang Song straightened up: "Let me go first."

"After inquiring about the situation from the reporting person, Li Guifen, this morning, I conducted an overview and some investigative visits around the neighborhood."

"As Captain Gao mentioned, the suspicion of Li Guifen being involved can basically be ruled out."

"Both were remarried; they met last year through introductions and registered their marriage on February 1st before the New Year, holding a wedding."

"The wedding was not a big affair, attended only by friends familiar with both."

"They had a prenuptial agreement where their respective properties and finances remained separate."

"Every month post-marriage, they each contributed 2,000 yuan for household expenses."

"I also looked into their respective former marriages, both divorced three and two years ago."

"Li Guifen has a fourteen-year-old son who stays with her ex-husband."

"Zhao Kai had a unique situation; he divorced two years ago, and their twelve-year-old child was also awarded to him in the settlement. However, the child lives with his parents in his hometown and was never brought to stay with him."

"We checked, and neither of their ex-spouses currently reside in Binzhou City.

One is in Tianzhou, the other in Haizhou. Moreover, there’s no evidence of recent contact in their call and chat records."

Wang Song’s line of investigation was evidently more detailed.

"Regardless of whether the murder method is that of a serial killer, in such a complicated family situation, it’s crucial first to rule out the possibility of family involvement."

Wang Song had just entered the investigation and wasn’t yet caught in the mindset of a serial murder pattern like Gao Xiang and his team were.

"I checked their bank transactions and found nothing unusual; monthly child support payments from the ex-spouses appear normal."

"From these aspects, it seems unlikely that Zhao Kai’s murder was caused by family reasons."

Wang Song looked at Gao Xiang: "So the judgment made by Captain Gao’s team that the murderer is the same serial killer is likely accurate."

Some members of the Binzhou City Criminal Investigation Team looked at Wang Song with discontent.

Of course, there’s no issue; with such an obvious method of killing, how could it not be the same person?

Wang Song was unconcerned and continued: "So, why would the killer target four unrelated individuals?"

Wang Song’s gaze was sharp.

"We initially considered that there should be some connection between the victims."

Gao Xiang was also puzzled.

Wang Song’s thoughts or questions are also what they want to clarify, but the problem is that the past week yielded no useful clues.