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

Although the audio clip was brief, technicians, through voice feature analysis, preliminarily determined that the suspect was between 35 and 45 years old, likely spoke with a local accent, and had a long-term smoking habit. Combining this with previously captured suspect characteristics from surveillance footage, the technical department immediately entered the relevant information into the national population database and criminal suspect database for facial and voice feature comparison.

Meanwhile, Wang Shuai's team didn't stop. They conducted a thorough door-to-door search of the old alleyways west of the North Square. There were 32 households in the alleyways, and the team members knocked on doors to ask if anyone had seen a man matching the suspect's description. Most residents said that the alleyways had frequent pedestrian traffic and many migrant renters, making it difficult to remember everyone's appearance. However, an elderly woman living alone provided a crucial clue: "The night before last, around 10 pm, I was sewing clothes by the window when I saw a man carrying a black bag and wearing a hat walk out of the alley. It seemed like he came from a rented room in courtyard number 3. Courtyard number 3 is mostly inhabited by migrant renters; it's a mixed bag, and usually, few people pay attention to him."

Wang Shuai immediately led his team to Courtyard No. 3. It was an old two-story building with eight rental rooms. The landlord was an elderly man in his seventies. He explained that most of the tenants in Courtyard No. 3 were day laborers with high turnover. One room on the second floor had been rented to a man named "Old Deng" about two weeks prior. They rarely saw each other; all they knew was that he left early and returned late every day and was not very talkative. "Did he provide a copy of his ID card?" Wang Shuai asked. The landlord pulled a rental contract from a drawer. The tenant information on the contract showed: Deng Tianfang, male, 42 years old, registered residence in Dengjia Village, Licun Town, Chengnan District.

"That's him!" team member Xiao Li shouted excitedly. Although the photo on the rental contract was somewhat blurry, the facial features bore a resemblance to the suspect's profile in the surveillance footage. Wang Shuai immediately arranged for his team to retrieve Deng Tianfang's identity information and contacted the Chengnan District police to assist in investigating his registered residence. The technical department also simultaneously entered Deng Tianfang's identity information into the database for facial recognition comparison.

At 3 PM, the technical department delivered exciting news: Deng Tianfang's facial image closely matched the suspect's profile in the surveillance footage, and his voice was also largely consistent with the audio extracted from the vehicle's dashcam. Thus, the identity of the suspect in Zhang Tiancheng's murder was officially confirmed—Deng Tianfang, 42 years old, from Dengjia Village, Licun Town, Chengnan District.

Wang Shuai immediately led his team to Deng Tianfang's registered residence—Dengjia Village, Licun Town, Chengnan District. Upon arriving in the village, with the assistance of the local police station, they located Deng Tianfang's family. Deng Tianfang's wife stated that he hadn't returned home for three years, their relationship had long since broken down, and they were in the process of divorcing. She only knew that Deng Tianfang worked in Chengbei District, but she knew nothing about his specific job or where he lived. Deng Tianfang's parents were elderly and in poor health, and knew very little about their son, only that he had been lazy and lazy in his youth and had been dealt with by the police once for theft.

From the description provided by Deng Tianfang's family, Wang Shuai's team learned that Deng Tianfang had a prior theft conviction, was withdrawn, had a violent temper, and a long-term gambling addiction, accumulating substantial gambling debts. This closely matched the previously speculated motive of "murder for money"—Deng Tianfang likely plotted to rob a taxi driver because he was unable to repay his gambling debts, and Zhang Tiancheng unfortunately became his target.

To locate Deng Tianfang, Wang Shuai's team split into three groups: one group stayed in Dengjia Village to visit Deng Tianfang's relatives and neighbors to understand his social relationships and possible whereabouts; the second group returned to the Chengbei District to search the rental house in Courtyard No. 3 on the west side of Beifang Square and retrieved surveillance footage from the surrounding area to track Deng Tianfang's movements after the incident; the third group retrieved Deng Tianfang's bank statements, WeChat and Alipay transfer records, as well as mobile phone call records to find his activity trajectory.

The search of Deng Tianfang's rented apartment yielded some initial findings. The apartment was simply furnished with only a bed, a table, and a wardrobe. No physical evidence related to the crime was found. However, in the corner of the wardrobe, a black hooded sweatshirt and a black baseball cap were discovered, perfectly matching the suspect's attire in the surveillance footage. Technicians immediately examined the sweatshirt and cap, extracting small amounts of hair and fiber samples, which were sent to the laboratory for comparison with samples collected at the scene.

However, the investigations on the other two routes ran into difficulties. Team members who visited Deng Tianfang's relatives and neighbors reported that Deng Tianfang had a bad reputation in the village, rarely interacted with others, and his relatives were unwilling to contact him, making it impossible for them to provide any valuable clues. Team members who retrieved Deng Tianfang's bank statements and call records discovered that his bank accounts had long been closed, his WeChat and Alipay accounts were frozen, and his SIM card was deactivated, clearly indicating that he had deliberately cut off contact with the outside world.

The surveillance and tracking efforts yielded no new breakthroughs. Deng Tianfang disappeared after the incident in an urban village at the intersection of Binhe East Road and Jiankang Street. This village has multiple exits and connects to several side roads and alleys in the Chengbei District, making surveillance coverage extremely weak. The team retrieved surveillance footage from all exits of the urban village, as well as all public and private surveillance cameras within a 3-kilometer radius, but found no trace of Deng Tianfang. Some villagers reported that there are many unlicensed and unregistered taxis in the urban village that specifically pick up people who do not wish to reveal their identities; it is highly likely that Deng Tianfang escaped the Chengbei District in one of these unlicensed taxis.

The forensic examination revealed that the hair sample extracted from the rented apartment matched the DNA from the cigarette butts found at the scene perfectly, and the fiber sample also matched the composition of the white synthetic fibers extracted at the scene, further confirming that Deng Tianfang was the suspect in Zhang Tiancheng's murder. However, even with his identity confirmed, finding Deng Tianfang's whereabouts became the biggest challenge facing Wang Shuai's team.

Wang Shuai immediately reported the situation to Lu Chuan. Lu Chuan convened an emergency case analysis meeting and deployed the next steps in the investigation: "First, immediately issue an online warrant for Deng Tianfang's arrest and offer a reward nationwide for clues; second, expand the scope of the investigation, retrieve surveillance footage from all entrances and exits in the North and South City Districts, as well as train, bus, and plane ticket information for those entering and leaving the city within 24 hours of the incident, to find Deng Tianfang's escape route; third, conduct an in-depth investigation into Deng Tianfang's social relationships, especially his gambling friends and creditors, to understand his possible whereabouts; fourth, conduct a thorough search of the urban village west of the North Square to check for any accomplices or hidden hideouts of Deng Tianfang." (End of Chapter)