On-site investigation is still continuing.
Xu Lin was strolling in the surrounding mountains and forests. Li Yinglong followed him with a confused look on his face.
They found several sets of footprints, probably for a while. Since it had rained a few days ago, the shoe prints were basically of no value.
Xu Lin, however, looked at it very seriously, trying his best to clean up some debris around and extract as much as possible from the shoe prints.
According to the analysis of his tracking skills, the occurrence rate of footprints at the scene is very high, and the extraction rate is also very high.
Fingerprint trace identification or DNA identification is certainly a very mature technology for personal identification, but due to limited legacy conditions, the extraction rate in on-site investigations is often not high.
The probability of fingerprints generally being collected during on-site surveys is only about 14%.
Most criminals, except those who kill with passion, are fully prepared for premeditated murders. They attach great importance to gloves, and the probability of leaving fingerprints is very low.
The DNA extraction rate is much lower than the fingerprint extraction rate.
Except for some cases such as female murder cases, or fierce fighting with the deceased, where key things in the evidence chain such as hair, saliva, blood, and epidermal tissue can be extracted, other types of cases are almost difficult to leave behind.
But compared to fingerprint traces or DNA extraction rates, the probability of footprints appearing is much higher.
Regardless of whether the suspect wore gloves to counter-investigation or whether the crime was committed for a relatively short time, he will leave corresponding footprints.
Footprints are less easily disguised than other traces.
Even if the suspect does not wear gloves when committing a crime, he will pay special attention to many movements to avoid leaving fingerprints.
However, as long as the suspect commits a crime, he must be walking at the scene. As long as he walks, he will reflect normal walking characteristics. Therefore, compared with other traces, footprint traces are more difficult to disguise.
Also, footprint inspection is the most effective means of conducting on-site analysis.
An important task of on-site investigation is to determine the direction of investigation from a technical perspective, accurately determine the nature of the case, determine the route to and from the scene, determine the crime process and the number of people, etc.
Since the occurrence rate of footprints at the scene is very high, the most important basis for judging the basic elements of the scene from a technical perspective is the footprints. For example, when analyzing and judging the number of perpetrators, the most important technical basis is the number of types of footprints at the scene.
The fingerprints left by the suspect at the scene cannot reflect the entire crime process, but any action of the suspect at the scene will leave corresponding footprints. As long as no mistakes are made during the extraction of the footprints, the suspect will be more completely discovered. The entire crime process. Therefore, discovering, extracting, and inspecting footprints is one of the most effective means of on-site analysis.
And the most important part is that footprints can reflect many personal characteristics of criminal suspects.
It can judge the age, height, body shape, occupation and other characteristics of the person wearing the shoes through preliminary inspection of the footprint size, pressure, etc., as well as physical health, development status, and whether the person is disabled, and the walking center and habits can be reflected.
Provide more clues for investigating and solving crimes.
Xu Lin carries the footprint extraction glue with him and extracts the found footprints.
After two hours of searching, he found a total of 7 sets of footprints.
Among them, three groups are relatively clear, and they are still remnants of shoes similar to hiking boots.
Among the other four groups, two are sports shoes and two are ordinary rubber shoes.
This mountainous area of Qingping Mountain has a relatively gentle terrain, with the mountain height less than 200 meters, and there are no distinctive landscapes or buildings around it.
Moreover, the jungle is dense and the mountain road is difficult to walk.
Therefore, basically no one goes up the mountain, which also brings convenience to criminals.
It was obvious that the murderer was quite familiar with this area.
After extracting these footprints, Xu Lin and Li Yinglong walked back.
The latter asked: "Team Leader Xu, are there any results from these footprints? Uh, I mean, are there any victims or murderers here?"
Xu Lin shook his head and said, "We're not sure yet. Let's take it back and test it first."
Then he asked: "By the way, Director Li, what is the identity of the person who reported the crime?"
Most people don’t go up the mountain, so why did the reporter go up the mountain?
When Li Yinglong heard what he said, he immediately said: "He is a villager who puts animal traps. He lives in a village more than 20 miles away from the foot of the mountain. He usually likes to set animal traps on the mountain and catch a few hares or wild boars. of."
When Xu Lin heard this, he was slightly stunned and asked: "Director Li, if I remember correctly, this seems to be illegal, right? Wild boar seems to have been listed as a second-level protected animal."
Li Yinglong nodded and said with a smile: "So he was temporarily detained in a police station below us. However, because he reported the case immediately after finding the body, we can consider him to have made a contribution, so we plan to educate him and then release him."
Xu Lin heard this and said, "Can you take me to see it?"
"sure."
As Li Yinglong said this, he led the way towards the parking spot down the mountain.
Just as the two of them came to the car and wanted to get in, Xu Lin's cell phone rang suddenly.
He took it out and saw that it was Fang Qingying's phone number.
So he immediately picked up the call and asked, "Xiao Fang, tell me, I'll listen."
Fang Qingying: "Team Leader Xu, after my testing, most of the death times of these skulls were between one month and forty days. However, two of them are relatively new and are being tested again. Also, the skulls have been Because of the incineration, the DNA inside was destroyed and now it cannot be extracted."
Xu Lin: "I understand."
A period of one month to forty days was within Xu Lin's expectation.
Because the dust cover on those skulls is not very thick, and the cave is relatively humid, the color of the skulls will definitely change if they are exposed to this environment for a long time.
"Bureau Li, let's go!"
Li Yinglong nodded, came to the cab in person, and drove towards the Qingping Town Police Station.
After a while, they arrived at the police station in the town.
Just as they got out of the car, a young policeman happened to pass by the two people's car. When he saw Li Yinglong, the policeman was immediately startled, and then said with surprise on his face: "Bureau Li!?"
He was obviously a little unsure. It was incredible that a director of the city bureau personally drove a young man to their police station!
When Li Yinglong heard the shouting, he looked at the police officer and said, "Hello, I'm looking for your director, Wang Chunlei."
"Oh, Director Li, wait a minute, I'll call the director right away."
"No, let's go in together."
Li Yinglong said and followed the young policeman.
Xu Lin also entered the police station with the two of them. He scanned the eyes of good and evil and found that all the police officers had white names. One or two had some crime points. The system prompted them to receive reviews about tobacco, alcohol and other things, but Xu Lin ignored them directly. .
As long as it doesn't harm the people, he won't care even if there are some flaws.
If the water is clear, there will be no fish. He still understands this truth.
Moreover, their crime values are all in white status and can be ignored.
The director of the police station, Wang Chunlei, is a middle-aged man of about 40 years old. He is very capable, has bright eyes, and has a good momentum.
