After 20 years of police service, Zhang Xinxin became a trace master who restored the truth of the case——

[Song of Laborers] "Listeners" at the crime scene

In the evening of November 24, Zhang Xinxin, who came to Beijing to participate in the national commendation conference for model workers and advanced workers, returned to Tianjin and instead of returning home, went directly to the office of the 13th Detachment of the Criminal Investigation Bureau of Tianjin Public Security Bureau.

That day was his night shift day. "As a people's policeman, the responsibility lies on his shoulder, and he cannot relax at any time."

Since 2000, Zhang Xinxin, who has been engaged in trace inspection since the police, has made a breakthrough in the case without clue and become a trace master to restore the truth of the case by virtue of his keen insight, rigorous thinking and meticulous professionalism.

Let physical evidence "speak"

If a leaf falls in the forest, there will be a sound even if the sound is weak. At the scene of the crime, a finger print, a shoe print, and a silent trace may become the key to solving the case.

Zhang Xinxin, who has been focusing on the inspection of on-site investigation traces for 20 years, is the "listener" who restores the truth. His mission is to let the silent physical evidence "speak" and rebuild the scene.

One morning in November 2015, the Tianjin police received a report from a citizen and found a female corpse in a green belt near a river.

Zhang Xinxin and his colleagues rushed to the scene of the crime. Unfortunately, reliable footprints and fingerprints cannot be extracted. The victim's face was covered with blood, but the source of the blood could not be determined.

After several hours of on-site investigation, no valuable clues were obtained. When everyone was at a loss, Zhang Xinxin, who had been crouching at the scene, found an abnormal situation in the periphery.

Not far from the corpse, Zhang Xinxin found a small piece of soft things abnormal, and there were many ants around it.

After washing this thing, I found it was a tip of tongue.

It is this discovery that points out the direction for the discovery of the case. A few days later, the investigators arrested the suspect in a dental hospital.

Trace inspection is the primary link of criminal case scene investigation, and any small physical evidence may change the direction of investigation.

For every crime scene, Zhang Xinxin firmly believes that "every contact must leave a trace", and with this persistence, he has never been to the crime scene without success.

In the past 20 years, Zhang Xinxin, who has won the honor of National Excellent Special People's Police and National Top 100 Criminal Police, has successively participated in the investigation of more than 1000 sites of various major criminal cases, examined more than 10000 pieces of trace evidence, and has won one personal first class merit, one second class merit, and four third class merit.

Site full of risks and challenges

The work of trace inspection and identification is hard and boring. It needs to calm down, endure hardships, and be tired. In addition, if there is a case, you must go to the scene.

Zhang Xinxin always remembers his first scene: the body smelled after being parked for too long. After entering the room, Zhang Xinxin almost vomited out. After the survey, the smell will not disappear for a week

"The nature of our work requires us to be exposed to a variety of sites. In some cases, the site environment is very harsh, and there are even many potential dangers," said Zhang Xinxin.

For example, when investigating the scene of a falling building, in order to find out the exact falling position and posture of the human body, climb outside the building for investigation; To investigate the scene of body dumping, sometimes we have to risk suffocation to go down the shaft, or even climb into the sewer to investigate; To survey the fire and explosion scene, enter the buildings that may collapse at any time and carry out the survey at the risk of possible secondary explosion at any time.

After the "8 · 12" catastrophic fire and explosion accident in Tianjin Port, Zhang Xinxin volunteered to form an assault team to enter an office building that was most seriously damaged and could collapse at any time for rescue survey and race against time. He worked at the central scene for 9 consecutive days, his eyes were severely congested by pollutants, and he still insisted on biting his teeth. He ventured into the core scene of the explosion for many times for inspection and evidence collection.

After that, Zhang Xinxin worked overtime for more than half a month, and worked with his comrades to sort out nearly 30000 words of on-site investigation records, more than 1000 on-site photos and 20 on-site investigation plan sketches, making important contributions to the accident handling work.

Now, Zhang Xinxin has a stronger psychological immunity to the harsh environment, but there are still two kinds of scenes that will make him feel a huge psychological impact. "One was the murder of a child, the other was the murder of a policeman, who couldn't help crying."

Over the years, running has become Zhang Xinxin's biggest hobby after work.

Running Zhang Xinxin is firm and confident. "In a complex and changeable crime scene full of risks and challenges, not only rich professional knowledge and calm mind are required, but also the courage to forge ahead."

Intensive cultivation business improvement capability

Zhang Xinxin, 43, was born into a family of policemen. Five of the grandparents and fathers were policemen. Later, under their influence, five members of his generation joined the team one after another.

In his childhood memory, the police is the embodiment of justice, a wall standing in the middle of the black and white world.

After graduating from high school in 1996, Zhang Xinxin did not hesitate to apply for the China Criminal Police Academy. He learned a lot of professional knowledge and honed his will quality after four years of college life. After taking part in the work, Zhang Xinxin concentrated on his business and improved his ability.

In recent years, Zhang Xinxin led the team to conduct in-depth research and analysis on a large number of theft cases, and made simulation samples of various locks by themselves. After studying locks and traces in various cases, Zhang Xinxin has created a series of new methods to test locks, making Tianjin's technical unlocking trace inspection level at the forefront of the country.

In view of the common phenomenon of using tin foil tools to unlock in burglary cases, he presided over and completed the scientific research project "Research on the Characteristics and Rules of Tin foil Tools' Unlocking Traces". He also published more than 20 academic papers in journals above provincial level.

Zhang Xinxin will keep the investigation data of each case, including relevant records after the case is solved, to compare and summarize the gains and losses in the work. For unsolved cases, they are also reviewed regularly so that new methods can be used to find breakthroughs.

Not long ago, Zhang Xinxin was just promoted from the position of deputy director of the trace inspection room of the Thirteenth Detachment to director of the audio-visual data inspection room. The responsibility is heavier and the work is busier.

Zhang Xinxin said that he never regretted choosing a police job, let alone a boring and unknown criminal technical post