Diary of a Criminal Investigator-Chapter 403: Extremely Brutal Methods

Crime Scene Investigation Office.

Lu Chuan is conducting analysis and identification of footprints collected from the scene.

Due to the large amount of blood at the scene, the traces of the culprit’s footprints are very clear.

In addition, Lu Chuan also collected some bloodstains on the wall, preparing to do some bloodstain pattern analysis.

By assisting the footprint identification results, the physical characteristics and age range of the suspect can be more accurately locked down.

In recent years, a term called criminal profiling has emerged in the field of crime scene investigation.

In fact, this is not considered a new term; criminal profiling has long existed, and the Haizhou City Public Security Bureau has specialist suspect profilers, currently assigned to the Image Investigation Team.

In recent years, criminal profiling has taken on a broader meaning, not only referring to the facial features of the culprit but also including physical characteristics, age range, personality traits, psychological traits, etc.

It is an emerging interdisciplinary subject that some mentors were already researching with doctoral students when Lu Chuan was in college.

Of course, the effect is not particularly ideal, because to accurately portray a suspect completely, it involves not only professional criminal investigation knowledge but also various aspects such as psychology.

Lu Chuan had some exposure to criminal psychology in college, but he didn’t study it in-depth.

"Footprints... length... width... pressure analysis and comparison of the forefoot and heel..."

There are many footprints left by the culprit at the scene, revealing a lot of information about physical characteristics, gait, angle of steps, stride, etc.; Lu Chuan has a lot of data to analyze and it won’t be finished quickly.

On the other side, Yang Sen and Old Bai are also conducting fingerprint identification analysis.

Liu Guodong found that the fingerprints collected at the scene are relatively complete, making the comparison relatively easy.

After the crime scene investigation ended, the second team was collecting fingerprints and footprints from everyone during the interrogation process.

"This fingerprint has been matched."

"It’s Zhang Shuang, the loader."

"I also successfully matched one, also a worker’s..."

The fingerprint identification process was relatively smooth, but the results weren’t ideal.

The weapon on the victim’s back had obvious wiping marks; the culprit handled the fingerprints before leaving.

Lu Chuan inspected every inch of the human skin on the wall, but no fingerprints were found; instead, many blood wiping marks were discovered, likely left when pulling and nailing the skin, but the marks are smooth, indicating the culprit likely wore thin, skin-tight rubber gloves.

The possibility of solving the case through fingerprints is getting smaller and smaller.

On the other side, the action team continues the investigation of the victim Zhang Xiaofeng’s interpersonal relationships.

Zhang Xiaofeng, in his early days, did odd jobs at construction sites, and later became a contractor due to his boldness and tenacity, gradually gathering a group of people under his wing.

After making his first fortune in the construction industry, Zhang Xiaofeng didn’t continue in this industry; later, he opened a game hall and ran a card room in the city, meeting people from all walks of life, with complex interpersonal relationships, and only opened the East Suburb Wood Factory five years ago until his murder.

"Divide into three groups: one group goes to Zhang Xiaofeng’s hometown to investigate the situation in the village, focusing on those who came out to work with Zhang Xiaofeng back then, to see if Zhang Xiaofeng had any enemies."

"Another group focuses on the game hall and card room Zhang Xiaofeng previously ran, to find out who he had conflicts with back then, with a focus on people with whom he had conflicts needing a thorough check."

"The third group focuses on the East Suburb Wood Factory, checking everyone who worked there over the past five years who later resigned, especially focusing on anyone Zhang Xiaofeng might have fired and might hold a grudge."

With Ren Qiang’s investigative experience, the culprit’s cruel methods suggest two likely possibilities.

First, the culprit is a psychopath, with a deeply psychotic obsession with murder; peeling and killing are to satisfy their morbid psychological needs. In other words, the culprit is likely a psychopath.

But this possibility is relatively small, as most of these people are serial killers who murder for simple psychological needs, without any specific motive; they could kill someone at random on the street.

A long time ago, Haizhou City had a rainy night killer who killed without any motive, just appearing on rainy days and looking for women in red clothes.

Rainy days, red clothes.

If these two conditions were met, he would kill. It’s that simple.

After being caught, psychological experts conducted a psychological test on him, revealing an extremely rare extreme obsessive personality disorder.

When certain stimulating conditions are met, the culprit cannot control his inner need.

However, this does not mean the person is psychotic; he can perfectly control his behavior. The methods used are secretive and cruel; he is a natural person with full behavioral capability.

The second, and what Ren Qiang considers the most probable, is retaliatory murder.

The culprit and victim had a significant feud, leading the culprit to adopt such extreme measures, using methods like cutting the tongue, sulfuric acid to damage the vocal cords, and skinning to torture the victim.

Moreover... Ren Qiang believes it’s probably related to the wood factory.

This kind of retaliatory murder could happen anywhere, but why did the culprit choose the wood factory?

It’s known that there are more than thirty people living in the factory, and committing murder there posed a great risk of exposure.

Additionally, the culprit should be very familiar with the wood factory’s schedule; otherwise, he wouldn’t choose to act inside the plant.

The risk of being discovered was too high.

At 9:40 p.m., in the Criminal Investigation Team meeting room, Qin Yong hosted a case analysis meeting.

"Forensic Doctor, Old Wang, please report the situation."

"Alright, the autopsy report is out; I’ll give a brief update."

"The victim, Zhang Xiaofeng, male, 49, from Haizhou City, died at 1:30 this morning, suffering severe torture before death."

"Here at the crime scene, at the corner where the human skin was nailed, we found the victim’s tongue along with a sulfuric acid bottle."

"The culprit used diluted sulfuric acid, which isn’t fatal but is sufficient to damage vocal cords."

"The purpose of doing so was probably to prevent the victim from making noise while being tortured."

"The fatal wound is on the back, penetrating to the heart, causing the victim to die from excessive blood loss."

"How about the skinning technique? Is there a professional background?"

Wang Changjiang shook his head; he understood Qin Yong was inquiring about whether the culprit might have a background in medicine or something similar.

"There shouldn’t be any such background; the culprit’s skinning technique was very rough, the skin wasn’t peeled off entirely, there were multiple tears, and traces of violent ripping were evident."

"From a forensic perspective, the culprit’s purpose was just to torment the victim."