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

Chapter 74 Tire Tracks
The world is always full of impermanence, chance and unpredictability.

No one knows what will happen tomorrow.

Song Kun is an old man from the Criminal Police Brigade of the High-tech Zone, and has served many criminal police officers.

I also know most of the people in the criminal investigation team.

Most of the criminal police at the scene of the crime had heard of Song Kun even if they had never met him.

Perhaps yesterday, or even this morning, some people still envied Song Kun's upcoming retirement life.

However, what I saw today was only a cold corpse.

For many members of the criminal police brigade in the high-tech zone, this is a difficult scene to accept.

Although Qin Yong had already arrived at the scene in person, Yuan Shaokang, captain of the criminal police brigade of the high-tech zone, was mainly in command.

Song Kun is his man after all, this is another traffic accident.

The emotional impact of the case is great, but in fact there is no need for criminal investigation to intervene.

It's just that now it involves hunting down the driver who escaped and caused the accident, which is a bit more complicated than ordinary traffic accidents.

However, with the current means, the vehicle basically did not run away after causing death in a traffic accident.

It can definitely be found, and the dead person is a criminal policeman. The traffic police detachment will definitely do their best.

Liu Guodong followed Lu Chuan's voice and walked over: "What's wrong?"

Lao Liu's heart is also very heavy.

He also has a day to retire.

However, who can guarantee that he can live until then?
"Here, there are tire burn marks."

Lu Chuan squatted on the ground and scraped the asphalt road with tweezers. His basic tire trace analysis skills allowed him to quickly determine the relevant information left by the scorched marks: "When the vehicle accelerates rapidly, the tires rub against the ground, and the rubber left behind rubs against the ground. trace."

When Liu Guodong heard this, his head roared.

"Are you sure it's the tire marks left by the vehicle's acceleration?"

Lu Chuan nodded affirmatively: "The traces left by braking and the traces left by acceleration have opposite directions of friction, so the friction direction of tire traces is also different."

Liu Guodong raised his head and followed a trace on the ground, looking at the impact point of Song Kun's car accident.

"You suspect it wasn't... an accident?"

Going in this direction, the vehicle follows a straight line and reaches exactly the point of impact.

"Ding!"

"Advanced task: Complete a qualified tire track analysis and uncover the truth about the death of criminal policeman Song Kun."

Lu Chuan picked up a small part of the burn mark with tweezers, put it under his nose and smelled it: "It's possible."

"The burn marks are strong and don't last longer than three hours."

"Also," Lu Chuan stood up and pointed to the sandy soil outside the roadside stone: "The sandy soil here has obvious traces of friction."

"It's supposed to be a four-wheel drive vehicle, and all four tires have grip marks."

"Also, the tires have a consistent tread pattern and similar levels of wear."

"The traffic flow on Longjiang Road is not large. The probability of two cars of the same model appearing in a short period of time is not high."

Opening the spot survey box that he carried with him, Lu Chuan dipped a cotton swab to pick up the rubber residue on the scorched marks: "I will go to the impact point to collect the rubber residue on the tire brake marks later, and do a comparative analysis of the components."

"Combined with the tread pattern imprint of the tire, we can determine whether the vehicle here is the vehicle that killed Song Kun."

Lu Chuan's discovery made Liu Guodong realize the seriousness of the matter.

Traffic accidents and intentional homicide are not the same thing.

Moreover, if Song Kun didn't die in a traffic accident, then who on earth wanted to kill a criminal policeman who was about to retire on purpose?

Is it because of what case Song Kun has now?
What did you find out?

Or did the people Song Kun arrested before come out to take revenge?

Or who did he have any grudges with in his own life?
Each possibility has different consequences.

Or rather, heaven and earth.

Death in a traffic accident is a natural and man-made disaster.

But if it is murder, the cause is private reasons, it is an ordinary homicide.

But if he was deliberately retaliated, then Song Kun died on duty and was a martyr.

"Xiao Lu, get the survey here first, and I'll report to Team Qin."

Lu Chuan nodded with a serious face.

In fact, Lu Chuan didn't think so much when he first arrived at the scene.

It's just that because the traffic police were already measuring the tire track data near the impact point, he didn't go forward.

After all, the profession has a specialization.

The traffic police must have more experience in dealing with traffic accidents than criminal investigation.

Therefore, Lu Chuan turned around at will, followed the direction of traffic, and walked up a few steps in the opposite direction.

But unexpectedly, these details were discovered.

One minute later, Qin Yong ran to the corner where the road turned, and Zhang Yongzhi, the head of the traffic police detachment, came with him.

"Lu Chuan, are you sure?"

Lu Chuan, who has collected the rubber residue, is now taking pictures of the tires.

"Team Qin," put down the camera, and Lu Chuan opened the browsing window: "This is the pattern of the tire marks on this side, which should be consistent with the tire pattern left by the brake marks near the impact point."

On the asphalt road, although the brake marks of the vehicle are a dark scorching mark, the depth of the scorching marks is slightly different because of the pattern of the tire itself.

In the eyes of professionals, these traces of different shades are actually tire patterns.

What's more, at the beginning and end of the trace, especially the end of the brake trace, when the vehicle brakes and stops, the rubber residue left by the tire rubber due to high-temperature friction will print the tire trace very clearly.

After receiving Lu Chuan's affirmative answer, Qin Yong's face was already extremely ugly.

Murder the criminal police, also by disguising the scene of the car accident.

Who is so bold? !
"Any other clues?"

Lu Chuan nodded: "I just conducted a preliminary analysis of the tire marks. Judging from the color of the tire marks, the vehicle involved in the accident should be a passenger car. After preliminary measurement of the tire width of 265, it should be a tire used by a large car or an off-road vehicle. "

Seeing Qin Yong frowning, Lu Chuan continued to explain: "The tires of vehicles all have certain specifications. Passenger cars, engineering vehicles, and trucks have different tire specifications because of their different uses."

"For tires of different specifications, the rubber material is different, and the color of the scorch marks is also different."

One of the main reasons why tire marks can become judicial evidence is that the specifications of tires are fixed.

Typically, tires are differentiated by vehicle type.

And there is a fixed English letter logo on the tire.

For example, the English letter PC stands for car tires, which are basically the tires used in private cars, whether they are ordinary cars or off-road vehicles.

LT stands for light truck tires, TB stands for truck and bus tires, AG stands for agricultural vehicle tires, OTR stands for engineering vehicle tires, ID stands for industrial car tires, AC stands for aircraft tires, and MC stands for motorcycle tires .

Lu Chuan pointed to the tire marks on the sand under his feet: "According to the distance between the front and rear tires at the start, the measured wheelbase of the vehicle is 2850, and all four wheels have grip marks, so it should be a four-wheel drive vehicle."

Lu Chuan pointed to Song Kun's body in the distance: "I just heard from the forensic doctor that Song Kun's body was directly impacted above the waist and close to the chest."

"Based on this height, the vehicle involved in the accident should be an off-road vehicle."

"The fragments of the bumper scattered on the road are white, so it is preliminarily judged that the vehicle involved in the accident is a white four-wheel drive off-road vehicle."

Lu Chuan completely entered the state: "I don't know the model of the vehicle very well, but there should not be many kinds of off-road vehicles with a wheelbase of 2850. We can roughly lock the vehicle brand."

Lu Chuan's thoughts became more and more clear, and his attention became more and more concentrated. He didn't notice how shocked the expressions of Qin Yong and Zhang Yongzhi were now.

(End of this chapter)