Chapter 7: Serial Murders

Chapter 7: The Serial Murder Case

Not at the crime scene?

Shen Qingye frowned, seeing how exhausted Wei Zhengyi looked, and finally decided not to press further. "Have you eaten anything?"

"Not yet," he replied with a grimace, rubbing his stomach. "I was so busy last night that I barely ate anything. I'm starving."

Shen Qingye said, "I have some snacks in my drawer. Do you want to eat something?"

Hearing this, Wei Zhengyi's eyes lit up, and he quickly nodded. "Yes, please!"

Seeing his reaction, Shen Qingye couldn't help but chuckle as she turned around and brought out a pile of snacks.

Wei Zhengyi let out an enthusiastic cheer and immediately pounced, tearing open a bag of biscuits and stuffing them into his mouth. The rich flavor exploded in his mouth, and he couldn't help but tear up. "You have no idea—we don’t even have water left in our office. I’m dying of thirst."

Hearing this, Shen Qingye was momentarily speechless before going back to pour him a glass of water.

Wei Zhengyi squatted in the corner, eating voraciously. Shen Qingye stood beside him, hesitated for a moment, then squatted down next to him and asked, "What exactly is going on with this case?"

Wei Zhengyi had already eaten two bags of biscuits and several chocolate bars, and the initial hunger had passed. He swallowed, wiped his mouth, and said:

"At first, it was in October two years ago when a fisherman caught a bag of ground meat in the river. When he opened it, he found it was human flesh. Terrified, he immediately called the police. The police tested it and confirmed it was human flesh, so they immediately opened an investigation. But because it was cold then, and the body had been soaked in the river for so long, all identifiable information on the body was gone, and they couldn’t find anything. In the end, it became a cold case.

"Then from March to September last year, three similar cases were discovered in succession. After investigation, they found that the methods of dismemberment and the locations where the bodies were dumped were similar to the first case, so they included the first case in this series. And because the last three dismemberments were found after rainy nights, they dubbed this series of cases the Rainy Night Serial Murders."

Wei Zhengyi sighed. "Because these cases were so brutal, they caught the attention of higher-ups, who ordered us to solve the case quickly. Captain Qin and the forensic team worked for over a month and found signs of assault before death. But the killer was too cautious—it seemed like he cleaned the bodies after killing them; plus, every time he committed the crime was on a rainy night, and the heavy rain erased any potential clues."

He spread his hands. "The case has been stalled for over two months."

Shen Qingye asked, "Didn't you try to investigate the victims?"

Wei Zhengyi shook his head. "Of course we did. Right from the start, we issued a missing persons alert city-wide, asking anyone with missing relatives to report it. Some people did come forward, but either the times of disappearance didn't match the times of death, or the DNA tests didn't match. To date, none of the bodies have been identified."

"Then how did you manage to find a lead later...?"

Wei Zhengyi said, "It was with the fifth case. When we received the report, we immediately began investigating, interviewing people around the dumping site, and finally, a fish breeder provided a clue."

"He said it had been raining heavily all night, and he was concerned about the fish fry he had recently stocked, so he got up in the middle of the night to check. He saw a white van passing by in the heavy rain. He found it odd—it was one or two in the morning, who would be out in such heavy rain? Then the next day, he heard about the bag of ground meat found not far away, and the van was heading directly towards that location.

"So we pursued the van lead, ruled out some obviously unsuitable ones, and used Luminol solution to test each of the remaining vans, and finally found traces of the victim's DNA in one of them.

"But just as we were about to celebrate, another issue surfaced," Wei Zhengyi said helplessly. "That van was a company van, usually used for transporting goods, and many people had driven it.

"Fortunately, the company had a well-organized management system, and there were records of who used the vehicle. So we vetted each person on the list, and in the end, none of them matched." At this point, he almost laughed at the absurdity.

Shen Qingye felt a pang of sadness listening to this.

"In the end, we had no choice but to start over. Since those who had used the vehicle were clean, we decided to look into those who hadn't.

"Because the people at the factory said the vehicle was usually there in the morning, and it hadn't gone missing. And since the killer usually operated at night, we speculated that the killer must have taken the vehicle after the factory had closed and everyone had left.

"But the factory had a gate, which was locked every night, and there were no signs of forced entry—so who could have gotten past the gate to drive the vehicle?"

Shen Qingye's heart stirred.

"The gatekeeper," Wei Zhengyi took a sip of water and continued. "The factory manager stated that the gatekeeper was in charge of opening the factory gate and was the first to arrive every day. That means the gatekeeper had the keys to the gate.

"So, our focus naturally shifted to Cai Limin."

"But when we actually met Cai Limin in person, we felt something was off. It's not impossible, but serial killers are usually younger. At over 50, life is more stable, and personalities are set; there's little reason to take such a huge risk. Plus, Cai Limin is known among his neighbors as a kind and honest man with no enemies. So, our suspicion of him lessened—"

Hearing 'kind and honest,' Shen Qingye's eyelids twitched, and she said, "That's not necessarily true."

Wei Zhengyi paused upon hearing this, then laughed: "I know, the boss mentioned it—yesterday's case, right?"

He gave her a thumbs up, praising: "You're incredible. In my two or three years on the team, I've never seen a murder case solved in just hours. It's really thanks to you."

Shen Qingye said, "You're overstating it. Even without me, Captain Yue and the team would've found the clues eventually. I was just a bit luckier."

Wei Zhengyi shook his head seriously: "You can't say that. If you hadn't spotted the issue in time, and we'd waited until after interrogating Lin Xiaofeng to search for clues, we'd have wasted precious time. What if Li Dazhi noticed the footprints on the AC unit and wiped them off? What if he ran away out of guilt? In murder cases like this, time is critical. Even a slight delay could lead to who knows what."

"That's why I say, you're incredible."

Shen Qingye paused, pursing her lips in silence.

Wei Zhengyi smiled and turned the topic back: "The suspicion is on Cai Limin, but we can't rely on gut feelings; we need evidence. But since Cai Limin is unlikely, could it be someone close to him? We followed this lead and eventually focused on his son, Cai Chengyong."

"Cai Chengyong, 23, works at a pork factory. He's tall, strong, and fully capable of the crime. We talked to Cai's neighbors and learned Cai Chengyong was obedient as a child, but after his mother left when he was eight, he changed. He stopped studying, and by his teens, he was running with street gangs, wandering aimlessly, driving Cai Limin crazy. Later, Cai Limin got him a job at the pork factory, and over time, he seemed to settle down."

He paused, then added: "Our investigation also found that, likely due to his mother abandoning him, Cai Chengyong harbors resentment toward women, and many have heard him express... such views."

"With the means, motive, and access to the van, Cai Chengyong became our top suspect. When we arrested him yesterday, we found his homemade van key at his place, as expected. We arrested both him and his father and interrogated them all night. But, well..."

Wei Zhengyi sighed again: "Cai Chengyong and Cai Limin admitted to making a spare key and stealing the van but denied any involvement with the blood or the murders."

Forensics found no evidence at Cai Chengyong's home, and the case hit a dead end.

Shen Qingye fell into deep thought.

Wei Zhengyi, unfazed, brushed crumbs off his clothes and smiled: "Hey, no worries. We'll just wait it out—see who cracks first."

Hearing this, Shen Qingye looked up at him, said nothing more, just smiled and said, "Are you done eating? I have more over there."

Wei Zhengyi rubbed his stomach, scratched his head, and smiled: "I'm about done, but if you have more, I wouldn't mind taking some. Brother Jiang and Brother Qiming are still over there."

Shen Qingye's legs were a bit numb from squatting, so she slowly stood up and said, "Wait for me a moment."

Not long after, she came back with another bag. Aunt Chen, fearing she might get hungry while working, often prepared some tasty and convenient snacks for her, which had almost filled a drawer.

Wei Zhengyi quickly thanked her, perked up, and ran back to the interrogation room.

When the door opened, Jiang Cheng and Zhou Qiming both looked over. The man sitting in the interrogation chair just moved his eyelids slightly, showing no emotion.

Wei Zhengyi glanced at Cai Chengyong, then looked away: "Brother Jiang, Brother Qiming, have something to eat."

Zhou Qiming exclaimed: "Did you go out to buy this?"

Wei Zhengyi said: "No, Xiao Shen gave it to me."

Having stayed up all night, they were already hungry, so they didn't stand on ceremony and grabbed a bag of bread to eat.

The bread, whatever it was made of, not only tasted good but also smelled very enticing. Cai Chengyong, who had been hanging his head, finally moved. His narrow eyes slowly lifted, his lips dry and peeling, his voice a bit hoarse: "I say, officer, when can I leave?"

Wei Zhengyi sneered: "When you've made everything clear, then you can leave."

Cai Chengyong chuckled, casually leaned back, the movement causing the handcuffs on his wrists to clatter. He tilted his head, the corners of his eyes slightly raised, his attitude full of disdain: "Officer, I've told you everything I can. It's not something I did, you can't force me to admit it."

Wei Zhengyi slammed the table, glaring angrily, about to speak, but Jiang Cheng pressed his hand, swallowed the bread, and said, "Don't bother with him."

This guy is sharp and has nerves of steel; regular interrogation tricks don’t work on him. If that’s how it is, no point wasting more time on him.

Letting him sweat it out might do some good.

"Let him talk."

Wei Zhengyi shot him a look, let out a cold snort, and turned away.

Seeing them eat and completely ignore him, Cai Chengyong’s smile slowly vanished, and his eyes darkened.

·

It was still early, with some time to kill before work. Shen Qingye sat at her desk, her eyes on the papers, but her mind was wandering.

She rubbed her temples, hesitated, then finally got up, grabbed a few old case files from the archive wall. She spread out the thick files on the table. The details matched what Wei Zhengyi had said. The first case in October two years ago, the four consecutive cases last year, police investigation results, and forensic autopsy reports were all there. The bodies were too torn up, so there wasn’t much to go on. Nothing else could be figured out.

Shen Qingye drummed her pen on the table, lost in thought.

The problem is, the killer was too careful. There was no useful information on the victims' bodies; Cai Chengyong’s place was spotless, no trace of murder.

At most, we can nail him for copying keys and stealing cars.

To put him away, we need stronger evidence—the crime scene itself.

Shen Qingye flipped through the files, her fingers tapping lightly.

The first victim’s body parts were found in the Liujiagou River, Baofang County;

The second, in a forest outside Huilin County;

The third, at the border between Yizhuang County and Hedong County;

The fourth, in Baoxian County…

The fifth, in Guning County…

At first glance, these spots don’t connect. The only link is they’re all out in the middle of nowhere.

Baofang County… Huilin County… Guning…

Shen Qingye suddenly had an idea, jumped up, and grabbed a city map, marking those spots with her finger.

These counties are all an hour south of the city.

Cai Limin’s factory is in the industrial zone, south-central part of the city. Assuming Cai Chengyong drove out from the factory, no matter which direction he went, the time to leave the city would be about the same. So why were all the dumping sites chosen in the south?

But what if he processed the bodies in the south? Then he could only dump them nearby. Otherwise, driving from the south to the north to dump the bodies, then back again, parking the car properly in the factory before the workers arrived, would take too much time.

Only down south could he ensure enough time for the round trip.

South… South…

What’s down south?

Shen Qingye found a detailed administrative map and scanned it, her fingers sweeping over the dumping sites. Her gaze suddenly paused.

Baofang County… Caipo Village?

Cai Chengyong, Cai?