Diary of a Criminal Investigator

Generally speaking, the possibility of murder in cases of falling from a building is not very high.

Based on the probability analysis of existing cases of falls, suicides account for more than eighty percent.

Of the remaining twenty percent, half are accidental falls.

Real murders through falling account for less than ten percent.

The initial crime scene investigation was conducted by Liu Guodong.

The woman who fell showed signs of being violated before her death, and it was a violent assault.

This was what determined the nature of the case.

All the evidence consisted of one fingerprint and bodily fluids collected from the victim.

Due to contamination by bodily fluids, the quality of the collected fingerprint was very poor.

The blurry photos were not very clear, similar to a second reproduction.

Extracting fingerprints from human skin is the most difficult of all fingerprint extractions.

At that time, Liu Guodong used the iodine fumigation method to extract the fingerprint.

However, due to the secretions from the sweat and oil glands on the victim's body surface, combined with the interference of bodily fluids, the fingerprint collected was far from ideal.

Of course, even so, Lu Chuan judged with intermediate crime scene investigation skills that Liu Guodong had already done his best.

At the very least, the discovery of this fingerprint was already very impressive.

The hum of the computer fan roared again, and the sound of keyboard tapping echoed rhythmically.

In the meeting room, everyone looked at each other and knew that Lu Chuan was handling the fingerprint again.

"Is this... the sixth one?"

"Three matches, three lives..."

What they said might not refer to the victims, but possibly to the murderer.

For homicide suspects, being caught at least meant a life sentence.

Nowadays, death penalty verdicts are not as common as before, unless the case is particularly severe, has a bad influence, or the criminal intent is extremely obvious; otherwise, it's mostly life sentences.

Each time Lu Chuan successfully matches a fingerprint, it not only clarifies the injustices of the victims but also sends someone to prison.

The computer howled, a frenzied howl.

It had the vibe of a goddess trapped in a dead-end alley by several burly men.

The hysterical vibe was unmistakable.

"Next time the bureau conducts a fingerprint battle, they should get some better computers; the noise is too loud."

"The noise is seriously affecting our fingerprint comparison progress..."

The fingerprint processing was relatively smooth, with pre-processing completed in less than two hours.

Watching the fingerprint on the screen become increasingly clear, Gao Wenxiang was flushed with excitement.

"Almost done... hmm?"

However, Gao Wenxiang quickly realized something was wrong.

As a qualified fingerprint identification officer, although the technical gap between him and Lu Chuan was like a chasm,

it didn't mean Gao Wenxiang was inadequate.

In fact, he was transferred out of the precinct as a genius by his superiors.

Having seen many fingerprints, Gao Wenxiang remembered them very clearly.

The fingerprint on Lu Chuan's screen felt very familiar to Gao Wenxiang, as if he had seen it before, yet it was separated by a thin veil.

"Brother Gao... does it feel familiar?"

Lu Chuan's feeling was even stronger than Gao Wenxiang's.

The familiar fingerprint seemed like it had just been seen.

Gao Wenxiang nodded affirmatively: "Do you feel familiar too?"

Suddenly, both of their expressions froze.

They had only looked at two fingerprints together that had not been successfully matched.

One was from yesterday afternoon, the fingerprint from the Zheng Bin murder case that Lu Chuan worked on.

The other was from the first homicide fingerprint they dealt with today, which didn't match in the system.

Lu Chuan immediately operated the system and pulled out the two pre-processed fingerprints from the Zheng Bin case and this morning's case.

After processing, the two fingerprints were relatively clear.

"Zheng Bin!"

Gao Wenxiang immediately recognized which fingerprint was similar to the one from the fall case.

It was the fingerprint left on the murder weapon at the Zheng Bin murder scene.

Upon hearing Gao Wenxiang mention Zheng Bin, Wang Song immediately looked up: "Old Gao? What's up?"

Yesterday afternoon, Wang Song was full of hope waiting for Lu Chuan's identification results.

Unfortunately, the comparison failed; the target person hadn't left a fingerprint sample in the system.

"Old Wang, come quickly! The fingerprint from the Zheng Bin case has matched!"

Within a few breaths, everyone gathered behind Lu Chuan.

Wang Song's eyes were practically glued to the screen.

"Who? Who is it?"

The match failed yesterday, but today it succeeded!

"There is no information on the other party, but the person who killed Zheng Bin and the culprit of the fall case in Qingjian District five years ago should be the same person."

The person who killed Zheng Bin, is the culprit of the fall case in Qingjian District five years ago?

Wang Song's expression changed; he had heard of the case from five years ago and knew it was handled by the Criminal Investigation Team.

"A habitual offender?"

"Killed a police officer nine years ago, committed murder at Qiang Jian five years ago?"

Sun Hao frowned; he knew both cases.

He had also participated in handling the cases back then, but clearly, no valuable information was obtained.

Wang Song's face was even gloomier.

Although the fingerprint comparison indicated that the same person was responsible for both cases, what of it?

The suspect killed Zheng Bin in the hills nine years ago; the case remained unsolved.

Five years ago, committed murder in Qingjian District; the case was still unsolved.

Everyone began discussing the two old cases.

"Is there a possibility of reopening the case from five years ago?"

"On its own... not very likely. But if combined with Zheng Bin's case... it's worth a try."

Old homicide cases are never given up, but police resources are always limited.

Generally, without major clues, old homicide cases won't be reopened for investigation.

Unless, the nature of the case changes significantly.

One killer taking two lives isn't quite sufficient.

There are plenty of serial killer cases.

Most of which remain unsolved, and you never hear of those cases being reopened.

Reopening a case differs from routine follow-ups, as it's conducted under the same standards as new cases.

"Let's apply for it first. Reopening might not be feasible, but... following up for a couple of days should be fine."

Lu Chuan checked the files; the fall case from five years ago was handled by Ren Qiang.

During a break, Lu Chuan called Ren Qiang.

"The suspect in the case from five years ago and the Zheng Bin case from nine years ago is the same?"

Ren Qiang was somewhat shocked.

He was in charge of the former case, while the latter affected the victim Zheng Bin, who had joined the force the same year as him.

"Currently, there aren't further clues."

Lu Chuan had discovered something, but it wasn't much help in capturing suspects.

"The fingerprint battle on my side ends in five days; I'll check the case files then."

After hanging up the call, Ren Qiang sighed deeply.

Recalling the case from five years ago felt like it happened just yesterday.

And Zheng Bin—wasn't he just about to become a father back then?

Gathering his emotions, Ren Qiang headed to the archive and retrieved the files and evidence from the fall case five years ago.

Unlike the outdoor homicide of Zheng Bin, the fall case had seen significant progress.

The suspect pool was somewhat smaller.

After all, when the fall occurred, the number of people in the building was finite.

Screening everyone wasn't difficult.

In fact, at that time, they collected fingerprints and DNA from people across the entire street and several nearby districts.

Unfortunately, the fingerprint comparison was unsuccessful.

There was also no significant progress in DNA analysis.

However, based on the time the crime was reported, they could confirm that the suspect was nearby, perhaps even still inside the building.

Who could it be?