Chapter 110 Trace Physical Evidence
If the identity of the deceased cannot be determined, it is impossible to advance the case by investigating the interpersonal relationships of the deceased.
Moreover, the murderer abandoned the naked body, obviously not wanting to reveal the identity of the deceased through information such as clothing.
As for ID cards, mobile phones and other items, they must have been hidden or destroyed by the murderer.
From this point of view, the murderer acted very carefully, and the result was obviously successful.
Lu Chuan thought for a while and looked at Yang Sen and Lao Bai: "Brother Yang and the others collected some footprints outside the wall. I want to try to analyze them first."
"Also, the murderer is turning over the body. I think we can do some data analysis on the process of throwing the wall into Qinghe Amusement Park."
Footprint analysis, Liu Guodong knew that Lu Chuan was also good at this.
However, the clarity of the footprints collected this time is very poor, and multiple footprints are superimposed.
Furthermore, according to Zhang Hui’s initial visit near the crime scene, the murderer should have dumped the body between 11pm and 6am last night.
Because Zhang Fugui’s last tour every day is at eleven o’clock in the evening.
According to Zhang Fugui, he always uses a strong flashlight when he patrols at night, taking pictures of every corner of the place that he cannot go.
Zhang Fugui was very sure that where the body lay was not found during the inspection at 11 o'clock last night.
This confirms that the earliest time the murderer dumped his body last night was eleven o'clock in the evening.
As for the time in the early morning, it is because around six in the morning, before dawn, there are already old people doing morning exercises walking in the small amusement park.
If the other party dumps the body during this time, it will be easily discovered.
Based on the fact that when the body was abandoned, it scraped against the wall and blood flowed out, and then it was frozen stiff, the murderer must have dumped the body after 11 o'clock last night and before 6 o'clock this morning.
When Lu Chuan and others arrived at the scene, it was already 10 o'clock in the morning.
The path outside the wall has been passed by countless people doing morning exercises.
Even if the murderer did leave footprints, it would be difficult for Lu Chuan to analyze the results after being trampled by many people.
"Footprints... let's try it first."
Liu Guodong obviously knew the difficulty here: "What do you mean by data analysis?"
"That's it," Lu Chuan opened his mouth The survey notes just recorded at the site: "The height of the fence at the Qinghe Amusement Park construction site is two meters."
"The deceased was about 1.63 meters tall and weighed about 55 kilograms."
“If the murderer wants to climb such a corpse over the wall, he must first make sure that the murderer is in good physical strength.”
"And the height of the murderer's arms must at least exceed the fence, which is two meters and two meters high."
Lu Chuan had carefully measured the specific height of the fence at the scene.
Lu Chuan stretched out his arm and said: "The length of a normal person's raised arm is forty centimeters above the head."
"In this case, the murderer is at least 1.8 meters tall. About ”
“He is 1.8 meters tall and has good physical strength. The murderer’s gender can basically be determined to be male.”
"In addition, I would like to collect trace evidence from the corpse."
Collect trace evidence?
“Are you sure?”
The reason Liu Guodong raised this question is because it is not easy to collect trace physical evidence.
The so-called trace evidence is actually extremely small criminal evidence.
Theoretically, any contact between two objects will leave certain traces.
For example, pollen on clothes, paint on palms, etc. will leave obvious traces of contact.
For some contacts, the traces will be very subtle. For example, when a magnet contacts an iron block, no traces can be seen on the surface after separation. In fact, the magnet must have the molecular structure of the iron block.
It’s just that the molecules are too tiny to be visible to the human eye, and even cannot be distinguished using specialized magnifying instruments. But the contact does exist.
The magnitude of trace physical evidence in forensic identification is obviously much larger than that of molecules.
Common trace evidence includes pollen, hair, dander, fibers, cosmetics, etc.
Not only is it difficult to collect trace physical evidence, but it is even more difficult to analyze and identify it.
The identification and analysis of trace evidence has a special skill card among the skills provided by the Lu Chuan system.
Different from general physical evidence detection and analysis, the identification and analysis methods of trace physical evidence are different and the instruments used are also different.
The Haizhou Criminal Investigation Detachment itself does not have the ability to conduct identification and analysis of trace evidence.
Even the Technical Appraisal Center of Haizhou City Public Security Bureau does not have such people and equipment.
In the whole province, only the Provincial Capital Public Security Bureau and the Provincial Department Technical Identification Center have trace evidence identification laboratories.
In other words, after Lu Chuan successfully collected the trace evidence, he had to send the collected trace evidence to the provincial department for testing.
“There is not much of a problem in collection, but in terms of identification and analysis, Team Qin needs to apply to the provincial department.”
Lu Chuan has intermediate spot investigation skills, so he has no problem collecting ordinary trace evidence.
"Okay, you can do a footprint analysis first and see if you can get any results, trace physical evidence... I'll ask Team Qin for instructions."
After Liu Guodong left, Yang Sen and Lao Bai got together come over.
"Xiao Lu, have you ever studied trace evidence?"
Yang Sen and Lao Bai were both frontline investigators who were transferred to the current investigation.
Most of the methods used are old methods and old routines.
In recent years, due to the improvement of technical level, it has become possible to collect, identify and analyze trace evidence, but it is not very good at it.
But I have heard of it and done some training in this area, but the effect is average.
Lu Chuan nodded: "I have learned some, and there is no other way now, so I will try it as a way to accumulate experience."
Yeah.
Lao Bai nodded affirmatively: "In our profession, just like forensic medicine, the more scenes we experience and the more corpses we dissect, the more we gain experience."
Yang Sen fully agreed with this.
Why don’t the police stations below, or even the criminal police brigade in districts and counties, have full-time on-the-spot detectives?
Can’t afford it? Of course not.
The reason why the criminal police brigade or police station below does not have full-time investigators is because there are not enough cases to train investigators.
Just like the Haizhou City Criminal Investigation Detachment, there is no full-time trace inspection, not because they cannot afford it, but because Liu Guodong and a few people are enough.
The Tianzhou City Criminal Investigation Detachment has full-time on-the-spot investigation and full-time trace inspection. This is because Tianzhou City has a large population and many cases, so it can have enough work to "train" full-time on-the-spot investigation and trace inspection. .
"This time we are going to help you, and we will also learn from this trace of physical evidence."
If you are in your position, you must seek your own government.
Although Lao Bai will retire in one year, he has a high level of ideological awareness and cannot miss the opportunity to improve his business skills.
While waiting for Liu Guodong to return, Lu Chuan took the time to analyze the footprints collected by Yang Sen and Lao Bai.
However, just as Liu Guodong was worried, the footprints were too confusing, with more than a dozen shoe prints superimposed, making it impossible to distinguish them.
Lu Chuan used some abilities in advanced fingerprint identification analysis, but there was nothing he could do about it.
Half an hour later, Liu Guodong returned to the site survey office: "Xiao Lu, Team Qin has agreed. He will go to the provincial department to apply. Then it's up to you."
( End of chapter)