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

Chapter 26 Fingerprint Developers

"Xiao Lu, the handlebar is the key point. Whether the other party is pushing or riding an electric bike, the handlebar is the part that the murderer must touch."

Yang Sen imitated the posture of driving an electric car and analyzed the places where the murderer might touch.

"There are no people in the two kilometers around the Xingfu Reservoir, and it is unlikely that the other party is pushing an electric car..."

Liu Guodong picked up a bright flashlight and shone it on the pedal of the electric car, carefully observing whether there were any footprints left in the room.

Pushing an electric car, the other party will not be able to touch the pedals, but riding an electric car will inevitably leave footprints on the pedals.

Lao Bai was cleaning the hair in the rear wheel bearing: "The corpse should have been cross-armed on the back seat at that time, so that the hair would be curled into the bearing."

"Ding!"

"Advanced task: Through the investigation of electric vehicles, fingerprint information is collected to help the operation team locate the range of suspects and solve the case of sinking corpses in Xingfu Reservoir."

Lu Chuan, who accepted the task, paid attention to the position of the armrest in the back seat.

The murderer is going to push the electric car into the reservoir, and his fingers are likely to touch the armrest of the rear seat.

While Lu Chuan and others were investigating the electric vehicle, the investigative criminal police of the action group were also advancing their work rapidly.

"Captain Qin, we have found out the origin of the electric car."

Ren Qiang took the registration information of the electric car given by the traffic police: "The owner of the car is Wang Song, and he owns a small restaurant."

"It was stolen three days ago, and the local police sent all Wang Song's alarm records."

Three days ago, it was the time when the victim was killed.

"Where was the electric car stolen?"

"No. 28 Beihu Road, right at the entrance of Wang Song Restaurant."

"Is there surveillance video?"

Ren Qiang shook his head: "The car stopped at a dead corner of the surveillance, and no trace of the car thief was found."

"Check, make a key investigation on this Wang Song," Qin Yong thought for a moment, and began to arrange the next task.

Qin Yong has seen a lot of self-stealing.

"Also contact the traffic police. The murderer who stole the electric car and dumped the body will definitely leave video data along the way."

"Determine all the road sections from Beihu No. 28 to Xingfu Reservoir, call all the monitoring, and don't let any one go!"

What is the homicide mechanism? It is to try our best to solve the case in the shortest time by investing the most resources!
In the detachment courtyard.

Liu Guodong and the others looked at the electric car in front of them with gloomy eyes, feeling a little helpless.

"Old Liu, the electric car has been soaked in water for too long, and there is no way to extract fingerprints."

For an afternoon, there was no progress on the current survey.

On the other hand, Lao Bai has already completed the DNA information comparison.

The hair in the rear wheel bearing of the electric vehicle belonged to the deceased.

At this moment, only Lu Chuan squatted on the ground, scanning every part of the electric car inch by inch.

Liu Guodong recalled that the fingerprints of the corpse extracted by Lu Chuan in the morning were extremely complete.

There was also the matter of helping Ren Qiang, the second group of the operation, to extract fingerprints at the scene of the arson case in the southern suburbs a few days ago.

Coupled with Lu Chuan's serious appearance now, he has expectations in his heart.

"Little Lu, is there anything you can do?"

Although Lu Chuan frowned slightly at the moment, his expression was relatively relaxed.

The intermediate fingerprint collection skill rewarded by the system contains many skills and methods.

Especially to deal with the fingerprints of fire and blisters, there are special fingerprint collection methods.

Although the electric car involved in the case was soaked in water for three days, Lu Chuan still had a way to collect the residual fingerprint information.

"Master, there are some discoveries."

Lu Chuan took out a purple light lamp from the inspection box and irradiated it on the handlebars, back seat and pedals of the electric vehicle.

"I have carefully observed these places, and there are no traces of wiping."

Liu Guodong nodded: "There is indeed no trace of wiping. There should be fingerprints on it, but after soaking in water, it cannot be extracted at all."

Liu Guodong has tried it just now, and ordinary physical and chemical methods cannot extract fingerprints.

After three days of soaking, the sweat that formed the fingerprints has long since melted.

Even the water-insoluble part of the oil will fade so much that fingerprints cannot be developed after long-term soaking.

In the field of surveying, the most feared thing is the case of encountering water.

The longer the time, the less things can be found.

Lu Chuan nodded: "After soaking, it is true that conventional methods cannot extract fingerprints, but some special methods can still have some effect."

After turning off the purple light, Lu Chuan frowned: "There will be some problems with the completeness of fingerprint extraction."

Oh?
There is a problem with the integrity, but it is not impossible to extract?
Liu Guodong raised his eyebrows: "Xiao Lu, you mean you can still extract it?"

"Yes, but I have to prepare."

after an hour.

Lu Chuan returned to the courtyard again.

This time, he had an extra small watering can in his hand.

During this hour, Liu Guodong and the others have been following Lu Chuan.

Witness with your own eyes how Lu Chuan evolved from a criminal policeman to a... chef.

Yes, chef.

This guy has been hanging out in the detachment kitchen for the past hour.

Turn over the bottles and cans inside.

With such a bottle of dark things.

"Little Lu... you... can do it?"

Lao Bai was a little confused. Although he didn't understand the details of what Lu Chuan did, he knew that Lu Chuan was making his own fingerprint developer.

However, isn't this stuff all the skills of the legendary masters?
Lu Chuan... self-made fingerprint developer?

Liu Guodong stared at the small watering can in Lu Chuan's hand slightly, "Lu Chuan... are you sure?"

The fingerprint developer is available in the criminal investigation detachment, and it is distributed from above.

In fact, the ingredients are very simple, mainly water, and some chemical coagulants.

This kind of fingerprint developer is commonly used nationwide and has a stable structure. It is a commonly used material when extracting fingerprints in current surveys.

But before the unified distribution, each place has its own commonly used fingerprint developer.

In history, there have been many cases where on-site fingerprints were destroyed due to the instability of the developer.

Therefore, the self-made fingerprint developer was not allowed to be used later.

Lu Chuan was able to make his own developer. On the one hand, it shows that Lu Chuan's strength in collecting fingerprints has surpassed the three of Liu Guodong.

But on the other hand, if there is a problem with the developer, it will destroy the fingerprints on the electric car.

This responsibility is Lu Chuan's.

It is normal for the electric car to be soaked in water for three days, and the fingerprints cannot be collected. No one can blame the people in the current survey office.

The big deal is to report it to the provincial department and let the experts from above come to investigate.

However, if the developer destroys the fingerprint, the experts from above will not be able to collect the fingerprint.

Then this responsibility is Lu Chuan's.

This is why cutting-edge technology is rarely applied in the field of criminal investigation.

Seeking stability is the lifeline in the field of criminal investigation.

Lu Chuan obviously understood the meaning of Liu Guodong's words.

He is concerned about himself.

As for concealing the use of developer, that's impossible.

Fingerprint developers are chemicals that are sure to leave marks after use.

These must be recorded. This is a process issue, and no one can violate it.

So, should Lu Chuan take risks?
(End of this chapter)