National Forensic Doctor-Chapter 869 - 807: Investigating the Murder Weapon

"If the perpetrator is one individual, then our prior investigative direction has been completely wrong."

Lei Xin’s frustration flashed and was gone. Being an experienced detective himself, he knew that mistakes were part of the norm.

Most investigations are a matter of trial and error; no one can claim a hundred percent certainty in cracking a case. Niu Tang, the forensic doctor from Qianjin District, was also skilled. His performance in past homicide cases had been noteworthy, particularly when it came to the identification of various paper materials. Niu Tang could even be considered a master in this area, with technical investigators from many provinces and cities traveling long distances just to have Niu Tang personally conduct a paper examination.

That three different wound patterns could be made by a single knife was a conclusion only a forensic expert like Jiang Yuan would dare to make from just looking at the photographs.

Lei Xin quickly tossed aside the issue of accountability and turned his head, "In that case, the perpetrator’s motive for the crime is likely not robbery."

"Carrying a cleaver alone is inconvenient if it’s for a home burglary," Liu Jinghui analyzed further. "If it were three people, having one carry a long-handled weapon is normal. But for a single person, carrying a heavy cleaver that weighs several pounds serves no purpose. If there’s a need to carry a knife, one would presumably carry one of better quality."

Liu Jinghui spoke in a somewhat casual, conversational tone, "The weight of a cleaver is at least equivalent to the weight of a bag a woman might carry. If it’s for a home burglary for profit, bringing along such a cleaver is very cost-ineffective."

"For self-defense?" Wang Chuanxing threw in a comment, more to prompt further discussion.

Liu Jinghui continued along this line of thought, "For self-defense, a small knife would suffice. Nowadays, people tend to avoid fighting with someone wielding a knife. Besides, the quality of that knife was so poor—to the point that it notched after a few chops and then broke after a few more—clearly, it wasn’t meant for attacking someone. It looks more like a knife bought on the spur of the moment."

"Impulse crime?" Lei Xin straightened up, frowning deeply.

If it were an impulse crime, it would be like going from a muddy trail to a snowy path—neither terrain was easy to navigate.

"At least it’s not for burglary," Liu Jinghui’s thought process was clear, then added, "If one anticipated using such a cleaver for a burglary, the best course of action would actually be to not go at all."

No explanation needed—Lei Xin nodded in agreement.

A home burglary is to steal, not commit a robbery.

The victim’s family was also not particularly wealthy, just an ordinary middle-class household. The total value of the property the perpetrator took after tossing the house was only a few tens of thousands of yuan. Families of this level were common in the same neighborhood. Therefore, if the goal were to steal, and there was a chance of a violent confrontation, switching homes would have been the best decision.

Alternatively, preparing ahead of time, choosing a time when the householders were out to make an unimpeded entry, or when only the female homeowner was present would significantly reduce the risks associated with a violent burglary. The perpetrator likely had some practical knowledge of society and would understand this bit of common sense.

Of course, there were some burglary perpetrators who were impulsive, randomly choosing a house to invade, willing to rob if the chance arose. But such individuals were generally dealt with quite harshly, and it would be extraordinarily rare to encounter one...

"So, if the perpetrator acted alone and not for robbery, could it only be for murder?" Lei Xin followed Liu Jinghui’s reasoning and asked another question.

"Hmm," Liu Jinghui hummed in affirmation, then said, "It’s more likely that it was for murder."

"We can re-examine the surveillance footage. Previously, we mainly considered a three-person scenario, but we also contemplated the possibility of them moving separately," Lei Xin randomly mentioned, followed by a click as he flicked his lighter to offer cigarettes to the group.

Jiang Yuan looked around and, seeing no indication that anyone else wished to speak, said, "We can check the surveillance, but there’s not much information there. Do the tech investigators have anything?"

"Nothing at the moment."

"The culprit has been quite cautious. They left behind no fingerprints or DNA. In terms of footprints, they covered their tracks with overshoes, and they essentially wiped out any trace afterwards. This family seems to have hoarded an excessive amount of salt and cleaning detergents," Jiang Yuan remarked with a touch of emotion.

"An avid Singles’ Day participant," Lei Xin replied, then added, "We’ve also considered the possibility of delivery personnel, but haven’t found anything yet."

He thought of Dama’s case and had casually checked on some delivery personnel.

At this point, Liu Jinghui snapped the case file shut and said, "It’s tough to track down people, so I suggest we look into the murder weapon. The quality of this knife is so poor, it doesn’t seem like it was bought in advance for the crime. Considering the family’s situation, they probably wouldn’t have the need to order a large cleaver online. Moreover, a thick-backed cleaver that’s been sharpened can be considered a controlled knife. I think there’s a higher chance it was purchased offline, possibly by the murderer from the surrounding area."

This hypothesis was somewhat bold, but Lei Xin had no objections. For him, the more leads to investigate, the better. If this lead turned up nothing, they could simply move on to the next.

Lei Xin had a map brought out and said, "If we’re certain it’s a cleaver, then there can’t be that many places it was bought from. Hardware stores around here, home improvement markets should have them, as well as these wholesale markets for hotel supplies and camping gear. Then, there are agricultural markets; some vegetable markets also sell them, and tax there’s the livestock market and dog market..."

While he said it wasn’t many, listing it out actually totalled up to seven or eight different types.

Lei Xin then made calls to familiar contacts at police substations nearby and eventually jotted down more than forty locations. The small ones were individual hardware or home improvement stores; the large ones included building material wholesale markets that spanned an area comparable to a university.

Lei Xin printed out the list and said, "Well, those are the places. Captain Jiang, would you like to rest or..."

"I’ll go to the livestock and dog markets. I’ll bring the Cold Case Squad with me," Jiang Yuan was also keen on taking a stroll.

Qinghe City’s livestock and dog markets were next to each other. The livestock market sold larger animals such as cattle, horses, sheep, pigs, and the like, including young animals and all sorts of related products: ropes for tying cattle, soybean meal for feeding them, ploughs for harnessing them, and butchers’ knives for slaughtering them. It had declined over time, giving way to the dog market.

The dog market not only sold dogs but also other small animals, with fewer birds and nowadays mainly focusing on pets.

Jiang Yuan’s Cold Case Squad had over twenty people, enough to search a market and perhaps even a bit over the top.

Lei Xin naturally had no objections and agreed immediately, then distributed the other addresses to other detectives, and the team split up into their respective Jettas, Fortuners, and Audis.

Liu Jinghui followed Jiang Yuan into an A6 and said with a smile, "You don’t usually go into the field much. What’s on your mind today?"

"The thick-backed cleaver was my guess, but it’s not entirely certain what weapon the murderer used. It’s better to take a look on site to be more sure. Maybe we’ll spot some unusual weaponry." Jiang Yuan paused, then added, "This murderer has a strong counter-surveillance mindset, using salt to preserve the bodies was quite clever. We need to give it some serious attention."

"Right, this case does seem to have quite a few areas that need attention," Liu Jinghui paused, then said, "If the murderer isn’t someone the family knew, the motive is highly questionable."

"How so?"

"Didn’t Lei Da from the task force ask in the meeting room if it could be a random crime? I didn’t answer directly. But is it random? It’s possible. However, if we interpret the case as motivated by theft, it doesn’t make sense, whether it’s random or not. But what if the goal was murder? For example... breaking in, rape, and murder?"

Jiang Yuan’s brow furrowed.

"From the photos of the victims, the mother and daughter both were quite beautiful. Of course, the daughter was quite young, just 11 years old, but we can’t apply common sense to this kind of deviancy." Liu Jinghui briefly mentioned, then continued, "This is just my speculation. I didn’t mention it earlier because there were a lot of people..."

"Actually, it makes sense," Jiang Yuan suddenly expressed his support, causing Liu Jinghui to pause.

"How so?" Liu Jinghui asked.

"One of the reasons I mentioned the thick-backed cleaver was that I saw signs on the heads of the two female victims that looked like marks from being hit with the back of a knife. There were marks that looked like they could be from a rolled edge as well, but we’d need to have the weapon to be sure. Anyway, at least initially, the murderer might have thought to knock out the two women without directly killing them."

"If that’s the case, it’s pretty much as you said," Liu Jinghui sighed, "If it was just for murder, straight murder would have sufficed... In this case, we can also analyze the murderer’s motive."