Out of the temporary headquarters, Xiao Ran took Zhang Lei to the downstairs where Niu Kun's family lived.

Because the community is relatively old, there are few people to clean it on weekdays, so the downstairs is not only cluttered, with all kinds of battery cars, waste, etc., but also dusty on the ground, except for the place where people often walk can see the ground, the rest of the ground is covered with a thin layer of dust.

When Xiao Ran came downstairs, he didn't immediately take the elevator upstairs, but lowered his head and looked around the entrance, squatting down from time to time, picking up a pinch of dust to take a closer look.

"What's wrong?" Zhang Lei saw this, squatted beside Xiao Ran and asked.

Xiao Ran frowned slightly, showed Zhang Lei the twisted dust on his fingertips, and asked, "Do you see it?"

"What do you see? What do you want me to see?" Zhang Lei didn't know why.

Xiao Ran flicked the dust off his fingertips, got up and straightened the recorder on his chest, and said expressionlessly: "You didn't look carefully." There's a very small amount of pepper particles in there. ”

"Pepper granules?"

Zhang Lei didn't understand why there was pepper in the dust, and even if someone's pepper was sprinkled in front of the building, what was the connection with the case?

It wasn't until he followed Xiao Ran into the creaking elevator that Zhang Lei figured out the meaning of Xiao Ran's words, and exclaimed, "You mean...... Who sprinkled this pepper to cover up the smell so that the dogs couldn't track it?!"

"It's possible, but not necessarily. ”

Xiao Ran said noncommittally: "The best way to avoid the tracking of police dogs is to have a water flow barrier, followed by sprinkling sulfur powder, but during this time, the weather is dry and rainy, and the community is dirty and messy, so it is too conspicuous to flush with water, and the color of sulfur contrasts with the color of the soil, and the color of pepper is very similar to the color of dust." ”

"However, there are not many of them, and even if they scatter that small piece, how can the nose of the police dog not be traced?" Zhang Lei was a little hard to believe.

"Who knows, dogs are dogs after all, and they don't say to people, 'The smell here is too choking, I won't go there'. ”

Xiao Ran replied casually, but he was thinking about a deeper question in his heart, that is, who sprinkled the pepper on the ground?

Mask the smell with pepper to avoid being tracked by police dogs, except for enthusiasts who are more interested in criminal investigation, the vast majority of ordinary people in normal life do not know this.

Even if you know this, or know about it on search engines, in that highly tense atmosphere, even repeat offenders who often deal with the police rarely think about covering up their scent.

As for the act of sprinkling pepper downstairs, Xiao Ran was more inclined in his heart that this was not a temporary thought after committing the crime, it should have been planned in advance, and even carefully planned.

However, through the surveillance footage that day, Xiao Ran knew that Niu Kun's family was unaware of Yan Yuehan's accident before the accident, and Niu Kun's parents and grandfather found out about the abnormality in the house after returning home, would they think of going downstairs to sprinkle pepper to cover up the smell?

Obviously impossible, not to mention that Niu Kun's family's interests and hobbies are relatively low-end, assuming that Niu Kun's family saw such a terrifying scene when they arrived home, they were almost scared to death, how could they think of covering up the smell.

Thus, after excluding the small probability situation, there is only one possibility with a high probability left: the pepper is Niu Kun sprinkled!

However, how did a young man who is in the third year of junior high school and has little contact with society develop such a strong sense of anti-reconnaissance?

Either he is very interested in the criminal field, and he has long been harmful to people's minds, and he has begun to make careful planning a long time ago, and with the current level of precocious children, the IQ of a 16-year-old is completely sufficient.

Or there is another possibility, combined with the faceless case that Ruan He once directed...... So, could Niu Kun be a newcomer who was taught by the criminal organization?!

Thinking of this, Xiao Ran's eyes tightened suddenly, and he couldn't help but want to call his colleagues from the network supervisor to ask, but the rattling elevator had stopped, and the floor where Niu Kun's house was located had arrived.

The elevator door opened with great difficulty, Xiao Ran looked at Zhang Lei, nodded, Zhang Lei understood.

Turning on the recorder, the two came to the door of Niu Kun's house, and before they knocked on the door, a faint fragrance penetrated into their nostrils, which was the smell of dish soap, and it was obvious that Niu Kun's house had been cleaned one or more times.

Xiao Ran and Zhang Lei sorted out their expressions, made a very natural appearance, and raised their hands to knock on the security door of Niu Kun's house.

However, after knocking on the door, no one in the room responded, and there was no sound, so Xiao Ran knocked again, and then a calm male voice with nervousness asked, "Who?"

"We are from the police station, and we visit it routinely. Xiao Ran said according to the original plan.

"Oh, good...... Here it comes. The male voice paused, and after a moment, carefully opened the door.

"Hello, hello comrade policeman, hello ......"

The one who opened the door was Niu Kun's father, Niu Shigui, who wore a thin woolen sweater on his upper body, sleeves rolled up to the crook of his arm, a pair of jeans on his lower body, a pair of cloth slippers on his feet, and a smile on the corner of his mouth, but the smile was a little unnatural, and there was a trace of panic in the depths of his eyes.

Obviously, he did not study how to control his expressions, and the actor's cultivation failed.

Xiao Ran raised his hand and showed his ID, of course, what he showed Niu Shengui was the front with his photo, and the negative side of the position, police rank, etc., Niu Shengui could not see.

"Please come in...... Please go ......"

Niu Shengui looked enthusiastic, led Xiao Ran and Zhang Lei in, and pretended not to know and asked, "Didn't you just ask two days ago, why did you ask again?"

"Alas, there's no way, isn't it that the little girl in the community next to her was abducted and killed by human traffickers, the above urged tightly, let me visit again, the leader moved his mouth, we broke our legs, and we were blind all day long!"

Xiao Ran pretended to have a perfunctory attitude and complained, so as to reduce the vigilance of Niu Shigui's family, and at the same time observe the situation in Niu Shigui's family.

The house was extremely clean, the floor was polished, Xiao Ran knew this before entering the door, and in the living room of the Niu family, two large suitcases were lying across the wall, and the zippers had not been closed, and the clothes in them could be faintly seen.

As for the rest of the Niu family, Niu Shigui's wife Tian Michun and his father Niu Man were sitting at the dining table eating, but they had already put down their chopsticks and came over, while Niu Kun, who Xiao Ran was focusing on, was reclining on the sofa and playing games.

When Xiao Ran and Zhang Lei first came in, Niu Kun turned his head and glanced at them contemptuously, and then continued to play King Pesticide with an expressionless face, without the slightest nervousness.

When Niu Shengui beckoned Xiao Ran and Zhang Lei to sit down, Xiao Ran casually raised his finger and pointed to the two large suitcases, and asked, "You guys...... Are you going to go far away?"

"Ah...... Yes, yes!"

Hearing Xiao Ran's question, Niu Shengui's voice trembled a little, and then said: "The child is not feeling well, often shouting that he has a headache, our hospital has checked several times and found nothing, so I inquired about other hospitals and took the child over to have a look." ”

"Oh, well, that's what you have to look up, the body is the most important thing. ”

Xiao Ran chuckled, looking very relaxed, but in fact, the muscles of his whole body were already in a state of preparation, he opened his notebook and took out a pen and asked, "Then it won't delay your time, I'll leave after understanding the situation." ”

After learning about the information of Niu Shigui's family normally, Xiao Ran asked: "Between 4 pm and 8 pm on the 16th, where are you and what are you doing, who can prove it?"

"Oh, I asked before, when my wife and I accompanied my dad to the hospital for a check-up, and we were always in the hospital, and when I came back, I heard that a child was lost, oops, I was nervous, we thought my child was gone. ”

Niu Shengui said very smoothly, and his wife next to him was still assisting, "That's it, my face turned white with fear at that time", as for Niu Shengui's father, Niu Man, was sitting at one end of the sofa, expressionless, stunned.

At this point, Zhang Lei looked at Niu Kun and asked half-jokingly: "Little brother, where were you at that time?"

As soon as they heard this, Niu Shengui and Tian Michun looked stunned, and Tian Michun grabbed the words: "Comrade policeman, why are you asking him what he is doing, he is just a child, and he hasn't finished junior high school, what can he understand?"

"This ...... I'm still in junior high school, I look like I'm in college?" Xiao Ran feigned surprise.

Tian Michun said repeatedly: "My children grow up early, and they are born better than other people's children. ”

"Oh, but I still have to understand, the leader explained, adults and children have to check, our leader said that the possibility of minors committing crimes cannot be ruled out......"

Xiao Ran said with a chuckle, but he had already noticed the unnaturalness in the words and deeds of Niu Shengui and his wife, and turned his head to look at Niu Kun and said, "Where were you at that time, what were you doing?"

"I was at home, playing games. Niu Kun didn't raise his head, and said indifferently, the game in his hand has not stopped.

Xiao Ran nodded, looked at Niu Shengui and his wife, and was about to speak again, Zhang Lei asked as planned: "Hey, where is your toilet?" ”

"Oh, that's the door. Niu Shigui stiffly pointed to the toilet door.

Zhang Lei got up and walked over, and said as he walked: "Oh, your house is so clean, this floor is clean, shiny and shiny...... Your house has just been renovated, and the walls are as fresh as they ......."

"Ah...... Right...... Yes, yes......"

Niu Shen Guiqiang replied with a smile, but his wife Tian Michun's face was already showing trepidation, and Xiao Ran still pretended to have no doubts, asking some inconsequential questions.

Zhang Lei came out of the bathroom, sat down with a sniff and said, "Your bathroom has too much water, why does it smell fishy?"

"Yes, no, you smell wrong, it should be the smell of my wife's cosmetics......" Niu Shigui hurriedly explained.

"Maybe I smelled it wrong. Zhang Lei nodded.

"My hand hurts when I wrote, it's time for you to remember. ”

Xiao Ran shook his hand, said hello to Niu Shengui and his wife, and handed the pen and paper to Zhang Lei.

Then he turned his head to look at Niu Kun and said, "Little brother, you said that you have been playing games at home all day, have you gone downstairs in the middle?" I heard an old man, you seem to have been playing with a girl downstairs that day?"

As soon as these words came out, Xiao Ran noticed that Niu Shengui's hands clenched suddenly: "That's right...... What's that, I haven't even prepared a glass of water after talking about it for so long, I'm going to pour a glass of water for the two of you!"

"Thank you, thank you. ”

Xiao Ran didn't refuse, and let Niu Shigui walk towards the water dispenser behind him, but the corner of his eye kept an eye on the surroundings, his whole body was tense, ready to explode at any time.

"Little brother, you haven't answered my question yet, did you play with a little girl downstairs that day?"

Xiao Ran asked, pulling on his coat and covering his right hand that was touching the pistol, because he had already noticed the cold light in the depths of Niu Shigui's wife, Tian Michun's eyes, and the slight sound of the soles of his shoes slowly approaching him behind him.

Niu Kun put down his phone and looked at Xiao Ran meaningfully: "What if it's me?"

"Host, danger!"

The prompt of the system came suddenly, in fact, there was no need for the system prompt, Xiao Ran had already opened from Niu Kun's pupils to Niu Shengui, who was holding a hammer behind him.

Xiao Ran's movements were like lightning, he instantly stood up and turned around, raised his hand and pointed the swarthy muzzle of the gun at Niu Shigui, who was gritting his teeth and preparing to attack.

Xiao Ran's eyes were sharp and trembling, and he said coldly, "What do you want to do?"