Attending ex-girlfriend's wedding, arresting the groom's officer on the spot

Wang Shuai noticed Song Guicheng's unusual behavior and pulled him aside: "Uncle Song, do you know something? It's okay, tell me, maybe it can help us find the murderer who killed Master Qin." Song Guicheng hesitated for a long time, looked around, and lowered his voice to say: "Officer, I can't tell anyone... Yan Ming's wife, Liu Min, seems to be getting quite close to other men lately."

Wang Shuai's heart skipped a beat: "Tell me the details, what happened?" Song Guicheng sighed, "About two months ago, I got up at night and saw a man bringing Liu Min back. The two hugged downstairs, and the man even touched Liu Min's face. Yan Ming wasn't home at the time—he works the night shift and usually doesn't get back until late at night." Song Guicheng continued, "Later, I saw him a few more times. The man drove a blue sedan and parked it at the entrance of the community. Liu Min would sneak into the car, sometimes not returning until the early hours of the morning."

"What did that man look like? Do you remember him?" Wang Shuai pressed, his heart pounding. Song Guicheng recalled, "He was about 180 cm tall, a little hunched over, wearing a black jacket, and had a mole on his left cheek. He spoke with a slight Northeastern accent." Wang Shuai's eyes lit up instantly—these features were almost identical to the man in black in the convenience store's security camera footage!
"Are you sure it's a black jacket? And a mole on his left cheek?" Wang Shuai confirmed, and Song Guicheng nodded: "That's right, I saw it clearly. Once, when that man was smoking downstairs, I made eye contact with him as I passed by. He had a mole on his left cheekbone, which was quite noticeable. Also, the jacket he was wearing had a white patch on the collar, which was different from what other people in the neighborhood wore."

Wang Shuai immediately instructed his team to retrieve the surveillance footage from the entrance of the residential complex. Although the main surveillance camera was broken, the private camera at the convenience store across the street could capture the scene at the entrance. Sure enough, at 8 PM on June 10th, the footage showed a blue sedan parked at the entrance. Liu Min came out of the apartment building and got into the passenger seat. The man driving the car was wearing a black jacket with a white patch on the collar, and although the mole on his left cheek was blurry, it was still faintly visible. More importantly, the model of this blue sedan was—a Volkswagen Lavida!
Wang Shuai immediately found Liu Min and placed the surveillance screenshot in front of her. Liu Min's face instantly turned deathly pale, and the water glass in her hand crashed to the ground and shattered. "This...this is my colleague Zhang Lei," her voice trembled violently, "We're just ordinary friends, he was just giving me a ride home."

“Would ordinary friends hug each other? Would he take you home in the early hours of the morning?” Wang Shuai’s tone became serious. “Did Master Qin know about your affair? On the night of June 13, before Master Qin was murdered, did you meet with Zhang Lei?” Liu Min’s tears suddenly fell, and she squatted on the ground, covering her face and crying: “It was…it was Yan Ming who found out about us. He had a fight with Zhang Lei and even said he wanted to divorce me.”

It turns out that Liu Min and Zhang Lei were former colleagues who reconnected six months ago and developed an inappropriate relationship. Two months ago, Qin Yanming accidentally saw Liu Min's chat history and discovered their affair. He immediately had a huge fight with Liu Min and confronted Zhang Lei, almost getting into a fight outside Zhang Lei's company. "Yanming said he would ruin Zhang Lei's reputation and divorce me, leaving me with nothing," Liu Min said, crying. "Zhang Lei was terrified and said that if Yanming really did that, he would 'not let Yanming get away with it.'"

Wang Shuai immediately investigated Zhang Lei's information: male, 39 years old, from Northeast China, currently working as a salesman at a building materials company, 180 cm tall, 70 kg, owns a blue Volkswagen Lavida, purchased 4 years ago, with a noticeable scratch on the side of the car—the exact same scratch location that Wang Shuai had previously discovered on the car registered under Liu Wei's name! Moreover, Zhang Lei had transferred the car to a person named "Liu Wei" six months ago, but in reality, Zhang Lei was still using the car; "Liu Wei" was just a nominee he found to avoid some traffic violations.

More importantly, Zhang Lei had a fresh wound on his right index finger, which he said was "cut while moving things," but the shape of the wound closely matched the laceration caused by Qin Yanming's broken fingernail. Wang Shuai immediately ordered the technical department to extract Zhang Lei's DNA and compare it with the skin tissue in Qin Yanming's fingernail crevices.

Meanwhile, Wang Shuai retrieved Zhang Lei's whereabouts on June 13: he left work at 5 pm that day and did not return to the company afterward; his mobile phone signal appeared near the Beihe River embankment between 9 pm and 11 pm on June 13, completely overlapping with the area where Qin Yanming's GPS signal disappeared; WeChat payment records showed that he bought two cans of beer and a pack of Yuxi cigarettes at a convenience store in Wanghai Community at 8:30 pm on June 13—the same purchase record of the man in black in the surveillance footage!
When Wang Shuai found Zhang Lei with the evidence, he was in a company meeting. Upon seeing the police, Zhang Lei's face instantly changed, and he tried to escape, but was stopped by the officers. "What did you do on the Beihe River embankment on the night of June 13th?" Wang Shuai's gaze was fixed on the mole on Zhang Lei's left cheek. "Why did you kill Qin Yanming?"

Zhang Lei initially tried to deny it, saying, "I didn't kill anyone! I only had a relationship with Liu Min and argued with Qin Yanming, but I didn't kill him!" It wasn't until Wang Shuai produced surveillance screenshots, WeChat payment records, vehicle information, and the upcoming DNA comparison results that Zhang Lei's psychological defenses completely collapsed.

“Qin Yanming forced me to do this!” Zhang Lei squatted on the ground, grabbing his hair with both hands. “He said he wanted to divorce Liu Min and would expose me at my company, causing me to lose my job, my wife, and my children! On the evening of June 13, I met him at the Beihe River embankment to talk, hoping to reconcile with him and give him money to stop exposing me, but he disagreed and even called me a beast and tried to hit me… I got angry and started fighting with him, and accidentally strangled him to death.”

At this moment, news came from the technical department: Zhang Lei's DNA was a perfect match for the skin tissue found under Qin Yanming's fingernails!
Standing in Zhang Lei's office, watching the bustling traffic outside the window, Wang Shuai finally breathed a sigh of relief. This clue to infidelity, discovered during the interpersonal relationship investigation, had finally connected all the suspicious points—Zhang Lei was the man in the black jacket driving the blue Volkswagen Lavida, and also the murderer of Qin Yanming. The "Liu Wei" mentioned earlier was merely Zhang Lei's proxies, and Zhao Gang was a wrongly accused suspect. Now, all the clues pointed to Zhang Lei, and the case had finally made a major breakthrough.

He took out his walkie-talkie and said, "Notify Captain Lu, we've located the prime suspect, Zhang Lei. The DNA match is correct, and he's in custody. Prepare for interrogation." Lu Chuan's voice came through the walkie-talkie, tinged with excitement: "Good! Be careful, bring him back to the station as soon as possible, and interrogate him in detail about the crime!" (End of Chapter)