National Forensic Doctor
Chapter 484 - 484 444 Heaven and Earth Net_2

484: Chapter 444 Heaven and Earth Net_2 484: Chapter 444 Heaven and Earth Net_2 But having reached the point of asking Xu Taining for help, Yu Wenshu dared not circle around the issue.

Yu Wenshu looked at Xu Taining with caution.

As the saying goes, a dog can’t change its habit of eating dirt; Xu Taining’s extravagant way of handling things wasn’t developed overnight.

It was, throughout various levels of the criminal police in Shannan Province, gradually indulged.

If he said he spent a lot, it might truly be a lot, but if you said he would save money, then you’d be blind.

“We can check the surveillance video, but I don’t think we should put too much hope in it.

In the middle of nowhere, if the murderer just wears a hat, holds an umbrella, or puts on a hoodie, we’re busy for nothing,” Xu Taining cut off another path.

Yu Wenshu nodded gravely.

“For this case, I think it ultimately comes down to the weapon.

Because the most unique aspect of this case is the weapon.

A modified nail gun—where does the nail gun come from?

Where was it modified?

Who modified it?

I think if we solve just one of these questions, the case can be cracked,” Xu Taining said, breaking the case down into fragments, yet making it clear and understandable.

A look of hope unconsciously appeared on Yu Wenshu’s face.

This analysis by Xu Taining was indeed much more meaningful than searching for evidence at the crime scene.

Xu Taining took a sip of tea, slowly saying, “There aren’t few but also not many people capable of modifying a nail gun.

My estimate, just Changyang City and its surroundings…

tens of thousands of people…”

Yu Wenshu was startled: “Tens of thousands of people?”

Xu Taining: “Those in the mechanical field, electricians, could all be possible…”

“Wait a second,” the political commissar said, “Even if we do find them, how do we prove they modified the nail gun?”

“The three crimes were all committed in the morning, two on workdays, one on a rest day.

The distance between each was far, so their alibis will definitely not be watertight.

We’ll screen out a list, then look for further ways to narrow it down,” Xu Taining replied swiftly.

Yu Wenshu knew that this was Xu Taining’s way of working: when undecided, first screen the list.

If few names come up, inquire specifically, use polygraphs, or undertake covert investigations.

If many are screened out, search in another direction, cross-refer, narrow down the list, and then go back to the first step.

If one were to say, Xu Taining’s method of solving cases was also quite simple-minded, different from Jiang Yuan’s simple approach yet more costly.

Yu Wenshu missed Jiang Yuan for a moment, then took a deep breath: “Let’s do it.

We’ll do as you said.”

This case admitted no further hesitation or waste of time.

In the afternoon.

While Xu Taining was still preparing, a reporter from “Changyang Evening News” arrived at the Criminal Police Brigade.

The reporter was invited by the bureau chief.

With a pleasant attitude, very professional and serious, they asked quite a few questions, some of which clearly prepared with the help of a professional.

Yu Wenshu obediently responded.

He was now the head of the provincial brigade, so who came to him was a reporter; had he still been the head of a large team, it might have been a fruit platter, the intentions being roughly the same: the case gets solved, rejoice with fruit, sweetly sweet, with the reporter writing about you.

If the case can’t be solved, there might not be a report, but there would definitely be a briefing sent up.

Yu Wenshu felt secretly relieved, thankful that Xu Taining was there.

That way, even in death, there would be no regrets.

…

At the same time, Jiang Yuan was also rushing to examine the nails.

The killer in this case had already murdered three people.

Although the intervals between the murders were irregular, one cannot expect a serial killer to adhere to any sort of schedule, especially with these random killings that lacked any conflict of interest.

It indicates the perpetrator does not follow social order and does not recognize existing moral standards.

Therefore, the killer might start killing a fourth person at any moment.

Completing the nail comparison as soon as possible was the best breakthrough Jiang Yuan could see at present.

Through the experience of numerous cases, participating and solving them, Jiang Yuan had gradually formed his own criminal investigative cognition.

In his view, the killer in this case had definitely spent a long time planning, imagining, and designing before committing the crime.

There is a fundamental difference between this type of serial killer and an ordinary person who kills.

Ordinary people kill often due to conflicts of interest, which creates ties and handles.

On the other hand, they usually only begin to plan and execute a murder when there is significant harm to their interests, and even then, planning does not necessarily lead to execution.

It often requires continuous harm to those interests or some triggering event to drive them to action.

As a result, when ordinary people commit murder, they are constrained by interests, limited by time, and not least, by emotional impulses.

All these factors limit them in committing the act, making it difficult for them to reach peak intellectual and physical states.

Serial killers are different.

The core of a serial killer is an anti-social factor, or in psychological terms, a lack of empathy.

Ordinary people might brutally kill small creatures like ants or insects without hesitation when they are as young as two or three years old, but as they grow older, they do so less and less.

This is the development of empathy and the result of social education.

Serial killers are not like that.

They have lost their capacity for empathy for various reasons, so their attitude towards humans is similar to that of a toddler towards ants.

However, their intelligence is normal, so they also understand the demands of social morality and where the boundaries of the law lie.

In order to evade punishment while satisfying their inner needs, serial killers often plan murders from a very young age and wait until adulthood to carry them out.

They have essentially self-trained.

Facing such criminals, ordinary methods are certainly not sufficient.

By this point, the police have probably already realized this—they would likely have already filtered out the weaker serial killers after their first crime.

Jiang Yuan, looking at the nails, could even imagine the killer’s satisfaction.

The killer could have used steel balls, but instead, he chose to use ordinary nails, which are harder to trace, and even modified a nail gun for this purpose.

This shows he was very aware that the “bullets” fired from the nail gun were his biggest vulnerability.

He could take away the cartridge cases, take the nail gun, be mindful of footprints and fingerprints, but he couldn’t feasibly remove the bullets or nails from the scene, as that might leave even greater risks.

However, from the work of these past few days, Jiang Yuan felt that the killer’s remaining time was getting shorter and shorter.

At first, Jiang Yuan was worried about not finding suitable nails, but over the past few days, his confidence had been growing.

In Jiang Yuan’s view, comparing nails and fingerprints actually had something in common.

What fingerprint comparison seeks, is not an exact match either.

It’s about identifying feature points, sorting by the number and similarity of these points, then selecting the closest match from the candidate fingerprints and eliminating those with obvious dissimilarities…

What is being compared with nails are, in fact, feature points as well.

The goal is to choose those locations likely to leave traces and keep comparing.

Now, Jiang Yuan could discard the majority of nails as soon as he got them in hand.

Many of the reasons for discarding didn’t even require a visual inspection—the weight could simply be felt in the hand and dismissed.

This also allowed his progress to advance significantly.

Who would have thought that Level 6 tool mark examinations would still have room for self-improvement and growth?