Era: Starting from the local police station

Guided by Zhang Hegui and his companion, a three-wheeled vehicle and two trucks arrived at the entrance of an alley.

Zhang Hegui pointed to the alley and said, "Gu Youliang's house is in this alley, in the west wing of the backyard of the fourth courtyard."

Jin Hong said, "According to the plan, I'll go to his house with Instructor Zhang and Section Chief Cheng. Deputy Director Jiang, you take some people to check out that yard."

Jiang Zhenghua nodded: "Okay."

Zhang Hegui looked hesitant.

Jiang Zhenghua said, "You should come with us."

Zhang Hegui nodded: "Turn around the corner, and that's the yard. The car is parked there."

Jiang Zhenghua and Jin Hong parted ways, and led by Zhang Hegui, they continued forward.

After turning the corner at the intersection and walking three hundred meters, Zhang Hegui pointed to a large courtyard facing the street: "Deputy Director Jiang, this is it."

Jiang Zhenghua looked out and saw that the wide earthen gate was open, the courtyard was overgrown with weeds, and behind it was a row of bungalows, but they were now leaning to one side and there were traces of fire and thick smoke on the walls.

"Comrade Zhang, where is this place? This area is in a bustling district, how come there's a place like this?"

"You don't know this, but this used to be a branch and transit point of Fangji Grain and Oil Store. All those houses were burned down."

Zhang Hegui paused for a moment: "This family lost its pillar and quickly declined. I heard that this courtyard now belongs to the subdistrict office. But they don't have the money to renovate it, so it's just been left here."

At this moment, Fang Ya, accompanied by her assistant and Guo Yong and two others, walked over.

Jiang Zhenghua smiled and said, "Teacher Fang, Comrade Guo, thank you for making this trip again."

Guo Yong smiled and waved his hand, "You're too kind. Our college hasn't started classes yet, and there are no training courses. We're just idling around at school anyway. I heard you reasoning through the case this morning, and it was quite novel. I can learn a lot from it."

Fang Ya chimed in, "Comrade Guo is right. I quite enjoy being there in person; I find it much more interesting than dry, boring lectures in a classroom."

Jiang Zhenghua glanced at the yard and saw a truck parked in the northwest corner: "What's going on here again? Didn't Deputy Director Jin say they were testing the liquid for croton oil?"

Zhang Hegui immediately asked, "Croton? Could there be that stuff in my mung bean soup? But wait, Xiao Dong drank it too. How come he's fine?"

As he spoke, the way he looked at Dong Zheng changed.

Dong Zheng immediately looked aggrieved: "Master..."

Jiang Zhenghua said, "I just suspect that this has nothing to do with Comrade Dong."

Fang Ya looked at Zhang Hegui: "Is this the original driver?"

Jiang Zhenghua nodded: "That's right. Master Zhang has had a bad stomach for many years. He ate a lot of spinach and tofu stew in the early morning, and then drank cold mung bean soup. This stimulation could very likely cause him to have abdominal cramps."

Fang Ya nodded: "Spinach and tofu can easily cause bloating and indigestion. If you add cold mung bean soup, the hottest days of summer are when the stomach and intestines are most vulnerable. He has a bad stomach, so there is a high probability that he will have diarrhea."

Jiang Zhenghua added, "However, given the killer's cautious approach, I suspect they would have taken precautions. So, I'm assuming they added a small amount of croton powder, enough to give Mr. Zhang diarrhea. But Mr. Dong, who is in good health, is fine."

Fang Ya shook her head: "There shouldn't be no problem at all; there should be bloating."

Dong Zheng nodded repeatedly: "Yes, yes, yes."

Jiang Zhenghua said, "Also, this is where Gu Youliang usually parks. Let's investigate carefully and see if we can find any clues. If the other party wanted to damage the reset spring, they would have to remove the tire, and they would definitely have used a jack. There should be marks on the ground where it was supported."

After he finished speaking, he looked at Zhang Hegui.

Zhang Hegui understood and immediately pointed to the side of the truck: "His truck is to the left of mine. We parked right next to each other last night to make it easier to move the goods."

Cao Hui immediately opened the canvas bag in his hand, took out a few strips of cloth, and handed them to the group.

Jiang Zhenghua said, "Master Zhang, you should also tie two straps to the soles of your shoes so we can distinguish the shoe prints. Comrade Dong, please wait here."

Zhang Hegui responded.

Once everything was ready, the group quickly walked over.

Guo Yong said, "The problem with the return spring is in the left front wheel."

Zhang Hegui pointed ahead: "The front of the car is roughly in that spot."

Jiang Zhenghua looked down at the ground and saw that all the weeds nearby had been trampled down, and there were many tire tracks: "It seems that Gu Youliang often parks in this area."

Fang Ya pointed to the ground and said, "Look here, this should be the newest one from yesterday, but this..."

The group looked over and saw a clump of hardened soil next to the brand-new tire tracks.

Guo Yong laughed and said, "Someone probably urinated here. What's the big deal?"

Jiang Zhenghua shook his head and said in a deep voice, "Teacher Fang, let's take the picture first."

Cao Hui asked, puzzled, "Deputy Director Jiang, what's wrong with this?"

Jiang Zhenghua asked, "What would happen if you urinated in the mud?"

Cao Hui was still puzzled.

Zhang Yi said, "The urine would have made a small hole, which looks like it was sprayed onto the tire, leaving traces of urine flow, but there is no hole here."

"What's the difference?"

Jiang Zhenghua explained, "You're a driving instructor, you use trucks all the time, so you don't see anything wrong with urinating on a truck. But would ordinary people dare to do that?"

Guo Yong pondered for a moment, then said softly, "I really wouldn't dare. If I saw it, I'd really get scolded."

"Who scattered that? Was it Gu Youliang?"

Zhang Hegui said, "Absolutely not. The driver might be facing the rear tires, but definitely not the front tires, for fear of any smell."

Guo Yong nodded and said, "That's true. If I saw someone urinating in my driver's seat, I'd beat them up."

Jiang Zhenghua frowned and said, "So it could only have been someone who vandalized the truck. But why would he urinate here? And judging from the marks, it must have been before the tire was removed. That's why there are scratches here from when the tire was being pulled. Doesn't he find it disgusting?"

"Maybe they needed to pee and didn't have time to go far?"

Jiang Zhenghua shook his head: "No."

Cao Hui pointed to the ground and said, "This area has been cleaned up, probably to cover up the footprints."

Jiang Zhenghua said, "Look for footprints nearby. By the way, Teacher Fang, what kind of shoes was Gu Youliang wearing?"

After taking a picture of the ground, Fang Ya stood up straight and said, "It's a pair of yellow rubber boots, with severely worn soles that are very smooth."

Jiang Zhenghua looked at Zhang Hegui, who immediately raised his foot: "I also wear rubber shoes. The front half of the sole is badly worn. My apprentice wears a pair with a thousand layers of soles."

The group immediately understood his meaning and began searching for other types of footprints.

Guo Yong squatted down and pointed to an irregular, shallow dent: "Look, this is what the jack was used for. Although the other party cleaned it, the dent is under the car, so it wasn't cleaned thoroughly."

Jiang Zhenghua gave a soft "hmm".

Guo Yong turned around and saw Jiang Zhenghua staring intently at the urine stain, deep in thought. He asked, "Why aren't you interested in proper marks, but you seem quite interested in this stuff?"

There was a hint of mockery in his eyes.

"I feel like there's something wrong here, but I can't quite put my finger on it."

Guo Yong waved his hand and said, "Hey, when you're doing something bad, it's normal to feel the urge to urinate when you're flustered."

Upon hearing this, Jiang Zhenghua's eyes lit up: "I understand."

Fang Ya looked at him, puzzled: "What do you know?"

Upon hearing Jiang Zhenghua's voice, everyone turned to look in their direction.

He asked, "What did Comrade Guo just say?"

Guo Yong pointed at himself, his face full of confusion: "I...what did I say?"

Jiang Zhenghua pointed to the ground: "You just said that when people are doing something bad, they panic and are prone to wanting to urinate. This person premeditated the crime, so their mental fortitude must be extraordinary. Under what circumstances do you think they would panic?"

Zhang Yi stood not far away: "When I was doing something bad, I got caught."

Jiang Zhenghua snapped his fingers: "Exactly. If someone were passing by the gate and glanced in this direction while he was fiddling with the tires, what would their reaction be?"

Guo Yong suddenly realized: "You mean he simply stood up and pretended to go to the toilet, so that the people outside wouldn't suspect anything? Won't the people outside be suspicious? Running in to use the toilet in front of a truck in the middle of the night?"

"What if that person pretends to be drunk and is carrying a bottle? If it were me, I definitely wouldn't come in. There's no point in arguing with a drunkard; you can't really reason with him. Besides, most people would just ask a question or shine a flashlight around; they definitely wouldn't interfere."

Jiang Zhenghua stroked his chin and said, "If it were just an ordinary person outside, they might not pay much attention and wouldn't need to pretend. But if it's a patrol officer, then they have no choice but to pretend."

Thinking of this, he immediately said to Cao Hui, "Go to the subdistrict office right away and ask if the security committee's patrol team passed through here last night."

Cao Hui responded, "Yes."

He then asked, "What about the police station?"

Jiang Zhenghua said, "Go to the local security committee first, and if they don't have it, then ask the police station. I suspect it's very likely that they are members of the security committee's patrol team."

"clear."

Cao Hui responded and quickly walked outside.

Shortly after, a security guard from the machinery factory called out in their direction: "Deputy Director Jiang, there are many shoe prints here."

Jiang Zhenghua strode towards that direction, with Fang Ya and Guo Yong following closely behind.

The security guard pointed to a corner near the roadside: "Right here, there are two cigarette butts."

Jiang Zhenghua looked down and saw several clear shoe prints, and a small clump of weeds trampled on the ground.

Fang Ya stepped forward and said to her assistant, "Xiao Hui, bring a ruler."

Soon, Xiao Hui took a measuring tape out of the box and carefully placed it next to a shoe print.

Fang Ya stepped forward, facing the footprints, and pressed the shutter button.

After some effort, three clear footprints were found.

"These are new leather shoes from the 43rd century. Judging from the depth, this person is strong. Judging from the distance of this step, his height is probably between 178 and 185 cm. This person's left leg should have been injured, because when walking, his right foot obviously puts more force on him."

After listening to Fang Ya's words, the group nodded in agreement.

Guo Yong looked at the location and asked, puzzled, "What's he doing here? Waiting for the time to pass?"

Jiang Zhenghua glanced back at the bustling street outside: "This street has a high volume of people. I guess it's not quiet early in the evening. He'll have to wait until people are asleep before he can make his move."

Guo Yong chimed in, "That explains it. If he were squatting here, no one would notice him unless they came in to check."

At this moment, Cao Hui walked in with two other people.

One of them was wearing a Zhongshan suit and looked to be in his forties; the other was wearing dark blue clothes and looked to be in his twenties, giving off a capable impression.

Jiang Zhenghua immediately went to greet him.

Cao Hui quickly introduced the identities of both parties.

Jiang Zhenghua extended his hand and shook hands with the middle-aged man: "I'm sorry to trouble Director Pan to make this trip."

Director Pan smiled and said, "Deputy Director Jiang, you're too kind. Cooperating with the police in handling cases is also the duty of our community security committee."

Releasing his grip, he said to the young man, "Captain Yan, why don't you tell Deputy Chief Jiang what happened last night?"

Captain Yan responded, "Yes, sir."

He slowly said, "Around 1 a.m., I led my team to patrol this street. When we passed this courtyard, we heard a noise. I shone my flashlight over and found a man standing next to a truck urinating. I shouted at him, but he mumbled incoherently, swayed, and was holding a bottle of liquor. Some people said he was drunk and couldn't speak clearly, so we left."

Jiang Zhenghua nodded: "Did you get a good look at the person's face?"

Captain Yan shook his head: "The distance was too far, and he even covered his face with his arm, so I couldn't see clearly."

"What are you wearing?"

"He was wearing a gray work uniform, similar to the uniforms worn by employees at the Hongxing Machinery Repair Factory. He was about 1.8 meters tall and very strong. By the way, his sleeves were rolled up at the time, and I could vaguely see a long scar on his right arm."

Are there any other characteristics?

"Nothing else was found."

Jiang Zhenghua reached out and shook hands with Captain Yan: "Thank you for the clue, Captain Yan. It was extremely important to us."

Captain Yan shook his head, a look of guilt on his face: "I feel guilty. If I had been more careful and gone to check, perhaps this wouldn't have happened."

Jiang Zhenghua said, "It's not your fault. It's just that the other party was too cunning, pretending to be drunk."

Director Pan interjected, "From now on, we should be more careful and question any suspicious person. We should be willing to go through the trouble rather than let anyone slip through our fingers."

Captain Yan replied, "Yes, Director."

Director Pan asked Jiang Zhenghua, "Deputy Director Jiang, I'm quite familiar with the Hongxing Machinery Repair Shop. Would you like me to inquire about it for you?"

Jiang Zhenghua shook his head: "Thank you for your kindness, Director Pan, but I need to report this matter and see what the leaders decide."

Director Pan nodded: "Alright, we won't disturb your work any longer. If you need our cooperation, please feel free to contact me."

Jiang Zhenghua nodded: "Definitely."

After Director Pan and his companion left, Cao Hui asked, "Deputy Director Jiang, what's our next step?"

Jiang Zhenghua glanced back at the courtyard: "Let's go find Deputy Director Jin and the others first, and then investigate the Hongxing Machinery Repair Factory."

At this moment, Fang Ya held up a glass cup containing some mung bean soup: "I'm taking this cup back with me. I estimate the results will be available in two days."

Jiang Zhenghua nodded: "Okay. Let's call it a day; there's nothing left to investigate here."