The information a corpse can provide in solving a case far exceeds the imagination of ordinary people.

Some say that corpses can speak, and in a certain sense, that is indeed true.

In most cases, a corpse can provide not only basic information such as time of death and manner of death, but also feedback on information about the perpetrator to a certain extent.

For example, knife wounds.

In the field of crime scene investigation, there is a specialized branch called injury assessment.

To put it in more detail, it is based on the assessment standards of human body injury severity.

When Lu Chuan has free time, he also helps the police stations or criminal investigation teams in the west with such assessments.

This is a rigid standard, providing legal levels of assessment on bodily injuries.

Based on the severity of the injury, it is classified into serious injury, minor injury, and slight injury.

Generally speaking, the vast majority of bodily injury outcomes are categorized as slight injuries. It’s not that slight injuries aren’t serious, but as long as they don’t cause functional disability or handicap, they are considered slight injuries.

The injury assessment standard is somewhat like treating the human body as an object. No matter how damaged the surface is, as long as it still functions, it’s mostly considered a slight injury.

However, if it results in functional disabilities, like deafness in one ear or blindness in one eye, that’s a minor injury. If both ears are deaf or both eyes blind, it meets the standard for serious injury as it entails loss of hearing or sight, thus qualifying as a serious injury.

Aside from the aforementioned injury assessments, this branch has also evolved into forensic injury assessment on corpses.

This is part of crime scene investigation, and Lu Chuan’s intermediate crime scene investigation skills include knowledge and experience in this area.

Lu Chuan explained to everyone, "From the angle of the back wound, by determining the angle of entry, we can calculate the height ratio between the perpetrator and the deceased. As for the depth... this thrust was intense and powerful, penetrating the thoracic bones protecting the heart, indicating that the perpetrator had great strength."

"Teacher Lu, is there a specific calculation method?"

A forensic doctor inquired. It was a great opportunity to learn. If he could master this, he could use it back home, wouldn’t that be wonderful?

Lu Chuan nodded, "There is. For instance, the knife’s angle can be calculated using sine function changes, through an empirical regression equation, and then corrected using probability methods..."

The forensic doctors initially listened with great interest since, after all, one needed at least a college degree to become a forensic doctor.

Basic sine and cosine function calculations were understandable.

But... what on earth was a regression equation?

Did I learn about that in university?

Among the forensic doctors present, the highest education level was a master’s degree, while the lowest was a police academy graduate.

This covered the entire university education spectrum of the mainstream domestic education system.

But...

Did we really learn anything about regression equations back then?

Probability correction?

Is this probability theory?

Is it nonsense?

Lu Chuan spoke enthusiastically, but he gradually noticed the confusion in everyone’s eyes.

"This... is roughly like this. Later, I will draft an assessment report, which will have legal validity."

"Yes, yes, well, in that case, our job here has made significant progress."

Even though Sun Jian couldn’t understand the calculation process Lu Chuan talked about, he didn’t find it necessary to understand it completely as long as it was helpful.

Almost immediately, the physical characteristics of the suspect were conveyed to Li Donglin.

"Adult male, with a high probability of being between 1.73 meters and 1.80 meters tall."

This was the conclusion made by Lu Chuan—considered a high probability.

Why attach a "high probability" to the conclusion? Because in fact, no one truly knows what the situation was when the perpetrator committed the murder.

For instance, the perpetrator’s actual height might be 1.6 meters, but standing on a 15 cm high stool while taking action, results would also show a height between 1.73 and 1.80 meters.

On the other hand, even if the perpetrator’s height exceeded 1.9 meters, but they were standing in a pit at the time of the murder, it would result in the same outcome as above.

Everything involves probability, especially murder cases.

Of course, these are just extremely small possibilities, which can virtually be ignored from the perspective of casting a wide net to catch fish.

"Good!"

With some characteristic data on the suspect’s physique, it greatly reduces the workload for the frontline.

This is also why frontline criminal investigators work so hard, yet no one competes with the crime scene investigators or forensic doctors for credit.

Those in technical roles can indeed be a great help to the frontline at times.

The identity of the corpse is still being further identified, but Lu Chuan’s work was the first to be completed.

The box housing the body didn’t exhibit anything unusual. Trying to find clues from the purchasing channels of the box would be a pipe dream.

However, the chain provided more important information.

Of course, not the chain itself, since such a chain can be found anywhere.

The crucial part is the type of links, where the suspect didn’t use a key, but used nails to hammer in a rivet.

Why did the suspect do this?

Does the suspect’s occupation show such characteristics?

In conference room number four of the Criminal Investigation Team in Tianzhou City, Li Donglin presided over the first case analysis meeting.

"So far, among the bodies found in the river, one has already had the victim’s identity confirmed, which is a significant breakthrough. Trace the deceased’s social relations, and do not overlook any detail."

"Especially focus on adult males, with a height between 1.73 and 1.80 meters."

"Moreover, this case spans a long period, and the suspect started committing crimes ten years ago, continuing until two months ago..."

At this point, Li Donglin paused slightly.

Concerning the timeline of the perpetrator’s crimes, Li Donglin conducted a detailed analysis and even consulted criminal psychology experts from the province.

Generally, in such serial murder cases, the perpetrator’s killing process is uninterrupted, relatively having a time critical point.

It means that there is a critical point in the time interval of the perpetrator’s murders, annually, every two years, or three years, rarely exceeding five years.

But this perpetrator is different.

The latest, fifth body, was killed two months ago.

The first body, eight months ago.

The second body a year ago, but not quite a year and a half.

The third body over five but less than ten years ago.

The fourth body over ten years ago.

This becomes somewhat odd. Three of the five bodies were killed within the past year or so.

One was ten years ago, and another five to ten years ago.

This average time span has no pattern at all and does not show the temporal critical point seen in most serial killers.

"The perpetrator is extremely vicious, with an unimaginably cruel killing method. Everyone must be highly vigilant during the investigation."

"Additionally, the crime scene investigation, forensic doctors, and the frontline need to quickly confirm the source of the corpse and identify the deceased."

"Furthermore, within a ten-kilometer radius of the Wang Family River where the body was found, a full-scale sweep detail is required!"