Diary of a Criminal Investigator-Chapter 302: Nothing Gained

Footprint Identification and Analysis plays a major role in narrowing down the range of suspects in criminal case investigations.

The more detailed the analysis, the more accurate the estimation of height, weight, and age range, which leads to better results.

Qin Yong forwarded the footprint analysis report from his phone directly to the task force’s group chat.

Going forward, everyone’s main focus was to look for a middle-aged man between the ages of 34 and 38.

"Teacher Zhou, do you recall if Zhou Yang had any friends in their thirties with a disability in the left foot?"

Father Zhou shook his head in confusion, "His friends are not serious people, and he never talks about these things in front of us. But if anyone knows, it might be Wang Zhi."

Zhang Hui and Ren Qiang’s team focused on investigating Zhou Yang’s social circles.

Meanwhile, Sun Jun was conducting door-to-door inquiries.

"A middle-aged man, in his thirties, about 1.75 meters tall, do you recall seeing any strangers like that?"

"Not very familiar. I got off work late last night, plus no one here in the apartment really knows each other, they should all be strangers, right?"

Most inquiries were not very effective.

Thirty-four to thirty-eight years old, height between 1.73 to 1.76 meters, weight around seventy kilograms...

There are too many people like that in the apartment.

Although Lu Chuan’s footprint analysis provided the clue of a missing left pinky toe, it’s not feasible to make everyone remove their shoes, right?

While outside, clues were being searched, the micro-trace evidence analysis on the crime scene side was also completed.

"I think this analysis result is quite useful."

Liu Guodong and three others were discussing the micro-trace evidence identification results, some of which were useful, but most were not.

Old Yang mentioned collecting minor substances from the murderer’s shoe impressions.

It was woodchips.

"The apartment rooftop shouldn’t have woodchips. I suspect they came from the soles of the murderer’s shoes."

"As for these fibers, I think part of it could be the residue left when the murderer dragged Zhou Yang."

"Not very useful."

On the rooftop, micro-trace evidence revealed the presence of woodchips, fiber materials, soil, amongst possibly seven to eight kinds of foreign materials.

But it’s hard to determine which one was brought by the murderer.

"This could also be if fibers fell from the murderer’s clothes?"

"It’s difficult to analyze," Old Bai shook his head, not entirely agreeing with Old Yang’s judgment.

"By the way, how did Lu manage to identify the left foot disability in the footprint analysis?"

Lu Chuan took a sip of water. "It’s quite simple. The perpetrator left many footprints while trying to clean up the drag marks at the scene."

"These footprints include standing postures, crouching postures, and walking footprints."

"I noticed that these footprints had a shift in the center of gravity on the left foot, especially when standing and crouching."

"In normal standing and squatting, the center of gravity on the feet moves back and forth but does not shift left and right."

"However, the murderer’s left foot center of gravity, when standing and crouching, had both front and back and slight left-right shifts."

"Additionally, based on the clarity of the shoe prints at the scene, we can deduce the perpetrator was wearing old shoes."

"The wear marks on the outer front of the left shoe were clearly less pronounced than those on the right shoe."

"Considering all these, it’s possible the perpetrator had an unsupported spot on the outside of the left foot, suggesting a missing pinky toe."

"Of course, we’re not sure whether this defect was congenital or acquired." 𝙛𝒓𝒆𝙚𝒘𝒆𝓫𝙣𝓸𝙫𝓮𝒍.𝒄𝒐𝓶

Footprint Identification and Analysis is not just a technical task, but also involves experiential skills.

There are actually books on this subject in criminal investigation.

For example, how to measure foot length and width, how to distinguish gait types; there are graphical tutorials for all these.

However, when applying this on paper, many who’ve studied can distinguish these.

But the reality of diverse shoe prints hardly corresponds with paper templates...

It’s simply not the same thing.

Liu Guodong recently studied two books on this topic.

Unfortunately, even with Lu Chuan’s guidance, he still didn’t quite grasp it.

Old Yang and Old Bai were even less familiar.

At their age, in their profession, mastering the use of instruments in micro-trace evidence analysis labs already showed dedication.

Not everyone likes, or is capable, or has the energy to embrace new things.

Especially after marriage, the trivialities of life tend to quash any naive dreams a man might have.

Liu Guodong, Yang Sen, and Old Bai epitomized this truth with a lifetime of experience.

To understand daily essentials, to understand children, to understand the wife, to understand parents...

For most, figuring out just one of these things makes them remarkable.

In addition, figuring out work and understanding oneself...

Grasping dreams...

Ha ha.

The harsh realities of life long taught middle-aged men that some things are best left unthought.

The time when technical growth in the Criminal Investigation Team was fastest was during the single days of being a bachelor.

With nothing else to do, one could only learn.

Even so, within a team, maybe only one or two could be outstanding.

For example, in Action Group Two, there were people who joined the team before Zhang Hui, but now besides Ren Qiang, Zhang Hui is the one who is assumed to be leading the team.

He was the first to take on tough, urgent, and dangerous tasks.

It’s not that others didn’t try hard, it’s just that they felt uneasy about entrusting matters to them.

Frankly, most people just do what they’re told and earn their salary.

Police officers are human too and need to provide for their families.

"Send these micro-trace evidence identification results to Captain Qin first."

"We’re not on the front line, unaware of their situation; maybe they can make use of them."

Liu Guodong nodded in agreement, while Old Yang went to send the results.

However, progress on the scene was far worse than Liu Guodong had imagined.

Zhou Yang died between 7:30 and 8:30 this morning.

The cause of death was drowning, with signs of falling from a height.

This indicates that when Zhou Yang was dragged by the perpetrator, he might have been unconscious but surely wasn’t dead.

No eyewitnesses were around during this crucial timeframe.

Sun Jun had searched the entire apartment building. From last night until 8:30 this morning, everyone who swiped to enter or exit the building was questioned.

The outcome yielded no leads.

Middle-aged men matching Lu Chuan’s analysis were present, and quite a number of them. In fact, Sun Jun even had some who closely matched the conditions remove their left shoe for verification.

However, nothing was discovered.

Zhang Hui also got in touch with Zhou Yang’s childhood friend, Wang Zhi.

Wang Zhi indeed provided some information, including people who had conflicts with or bore grudges against Zhou Yang.

Investigations cleared all suspects of suspicion.

Two days passed, all to no avail.