Diary of a Criminal Investigator

The traces covering the existing footprints at the scene are not a large surface cover, but simply footprints.

Lu Chuan lay on the ground, continuously observing. Did the suspect really float in?

Impossible.

The suspect made such a mess of the house, it’s impossible not to leave a trace.

Lu Chuan left no detail unchecked from the living room to the bedroom, carefully observing every tiny difference on the ground.

"Brother Hui, I have a frequency-tuned laser spectrum analyzer in my car. Can you get it for me?"

Lu Chuan seemed to have made some discoveries but was uncertain, as many details were still unclear in natural light.

"Sure, give me a moment."

Ten minutes later, Lu Chuan received the spectrum analyzer, pulled the curtains in the room, and the light instantly dimmed.

After turning on the spectrum analyzer, Lu Chuan adjusted the laser frequency, illuminating the ground, and suddenly a dense pattern of footprints appeared faintly.

Yuan Shaokang, standing aside, was stunned. Is the crime scene investigation technology really this advanced now?

But shortly after, Lu Chuan turned off the light source.

"Captain Yuan, it’s not possible now. Even with the curtains drawn, the light is still strong. Let’s come back at night. I have some discoveries to verify."

"No problem, but... it means you’ll have to work overtime, Lu Chuan."

"What’s the trouble with overtime? In our line of work, when do we not work overtime?"

"For now, don’t touch the scene. If we can confirm my idea tonight, we might be close to solving the case."

Lu Chuan didn’t go into too much detail because what he saw wasn’t clear enough and there was no conclusive evidence.

In the car back to the team, Zhang Hui couldn’t help but be curious: "Brother, what did you discover earlier?"

"Nothing much, just checking the footprints at the scene are the house owner’s family’s footprints, all left wearing slippers."

"There are three pairs of slippers in total, all kept in the closet at the entrance. I took a look, the shoes are relatively new, and the prints are very clear."

"But on some footprints, there are some spots, very negligible, not sure how they formed. At night, we can see it more clearly with the laser."

Zhang Hui felt at a loss, honestly not understanding much.

If it were fingerprints, he could have added something, but footprints...

After work, Lu Chuan first took Shen Yan home; it wasn’t dark yet and going there was useless now.

Then he went home for dinner, and the sky was completely darkened.

Instead of returning to the team for the car, Lu Chuan drove his own car directly to the High-tech Zone.

Fortunately, it was a bit closer in distance.

When Lu Chuan arrived, Zhang Hui and Yuan Shaokang were chatting.

"I suggest we focus the investigation on the residents in the building."

"Since the suspect didn’t enter or exit through the unit door, it must have been someone from inside the unit."

By common logical reasoning, this indeed seems to be the case.

There’s only one exit at the top of the building and one at the bottom, and someone always resides at the top, so the suspect can’t leave through the rooftop without disturbing the resident.

The High-tech Zone Criminal Investigation Team has already reviewed the surveillance at the unit door.

During the crime window, only residents and some delivery people entered and exited the unit, along with relatives of two households, but no strangers came in or out.

Leaving aside the residents for the moment, the delivery folks took no more than three minutes per entry—impossible to commit burglary in such a short time.

Thus, most likely, the burglary suspect is residing within the unit, committing the theft, and then returning home directly.

"That’s logical, but we can’t search all the residents in the unit, and there are no distinctive markings on the stolen cash; anyone could have $10,000, there’s no way to pinpoint the culprit."

"Those gold jewels might help narrow it down eventually, but how do you search for such small items?"

Even in a murder case without clear targeted evidence, the police can’t casually issue a search warrant to enter and search residents’ houses.

"True...."

"Hey, Lu Chuan’s here."

Zhang Hui waved, and the spectrum analyzer left in the room in the morning didn’t need to be moved back and forth.

Now with the sky completely dark and the curtains drawn, other residents’ lights had no impact. Lu Chuan turned on the spectrum analyzer and illuminated the ground.

The imaging was much clearer than during the day, with dense footprints like being sprinkled with fluorescent powder, standing sharply under the specific laser frequency.

"Here!"

And Lu Chuan’s hypothesis received further confirmation.

Each footprint had a distinctive spotty mark, like a bald patch in an oasis, very noticeable.

"What is this...?"

"The suspect’s footprints."

Hmm?

Lu Chuan crouched beside a bald spot, took out a camera to start taking pictures, as well as some swabs for collecting micro-evidence.

As he worked, he explained, "The suspect is clever. They didn’t leave footprints in the usual sense, but rather their footprints differ."

"They probably had something like stilts on their feet, resulting in these point-style marks on the ground."

Stilts?

Hearing this, Zhang Hui and Yuan Shaokang understood.

"Moreover, we found high-strength gel on the door lock this morning, typically used by magicians."

"Captain Yuan, is there anyone working in this field within this unit or neighborhood?"

"We didn’t conduct such specific checks initially, so I’m not sure."

Having made a discovery, Lu Chuan quickly completed the collection of point-style marks.

"Give me some time. From these point-style footprint marks, we can only roughly estimate the suspect’s weight. I’ll perform a micro-material analysis to figure out what the suspect tied to their legs was, and you should investigate people with similar professions for a cross-reference."

"Alright, I’ll arrange it right away."

Walking on stilts, this is not something an average person can manage—it requires extensive practice.

And being able to maneuver on stilts indoors, that requires more than ordinary skills, a beginner is unlikely to succeed.

The hardest part of stilt walking is not standing or walking, but bending and stooping to perform large movements.

The suspect’s stilts indoors are unlikely to be very tall, presumably just to disguise the footprints. Yet, even if not tall, they aren’t the person’s actual feet.

So, Lu Chuan suspects they might be a professional.

Without delay, Lu Chuan returned to the Criminal Investigation Team.

The suspect’s stilts weren’t metal; otherwise, there’d be drag marks on the marble floor. Based on the trace size, it likely was some type of wood.

Lu Chuan collected some micro-materials to see if effective component analysis could be done.

The remaining task was the analysis and identification of the marks.

Since the stilts’ material wasn’t metal, the marks formed upon ground contact show subtle differences due to force direction and center of gravity shifts.

Lu Chuan now needs to calculate to roughly analyze some basic information about the suspect.