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

Chapter 110 Trace Evidence
If the identity of the deceased cannot be determined, it is impossible to advance the case by investigating the deceased's interpersonal relationship.

Moreover, the murderer abandoned the naked body, obviously because he did not want to reveal the identity of the deceased through clothing and other information.

As for ID cards, mobile phones and other items, they must have been hidden or destroyed by the murderer long ago.

From this point of view, the murderer's behavior was very cautious, and the result was obviously successful.

Lu Chuan thought for a while, then 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 in the process of throwing the corpse over the wall into Qinghe Amusement Park. I think we can do some data analysis."

Liu Guodong knew that Lu Chuan was also good at footprint analysis.

However, the clarity of the footprints collected this time is very poor, and multiple footprints are superimposed together.

Moreover, according to Zhang Hui's preliminary visits near the crime scene, the time for the murderer to throw the body should be between [-]:[-] p.m. and [-]:[-] a.m. last night.

Because Zhang Fugui's last time to tour the field every day is eleven o'clock in the evening.

According to Zhang Fugui, he used a strong flashlight to patrol the venue at night, taking pictures of every corner and corner of the places he couldn't go.

Zhang Fugui was sure that he didn't find the location where the corpse was lying when he patrolled the venue at eleven o'clock last night.

This determined that the murderer's earliest time to dump the body last night was eleven o'clock in the evening.

As for the time in the early morning, it was because at around six o'clock in the morning, there were already old people doing morning exercises walking in the small amusement park before dawn.

If the other party throws the body during this time period, it will be easy to be found.

Combined with the time when the corpse was thrown away, it scratched the fence and blood flowed out, and then it was frozen to death. Judging from the fact that the murderer must have thrown the body after eleven o'clock last night and before six o'clock this morning.

When Lu Chuan and others arrived at the scene, it was already 10 o'clock in the morning.

I don't know how many morning exercisers have passed by the path outside the wall.

Even if the murderer did leave footprints, it would be difficult for Lu Chuan to analyze the result after being trampled by many people.

"Footprints... let's try first."

Liu Guodong obviously knew the difficulty here: "What do you mean by data analysis?"

"It's like this," Lu Chuan opened the field survey notes he had just recorded on the site: "The height of the fence at the construction site of Qinghe Amusement Park is two meters."

"The deceased was about 1.6 meters tall and weighed about 55 kilograms."

"The murderer wants to turn such a corpse over the wall, first of all, he can be sure that the murderer is physically strong."

"And the height of the murderer's arms should be at least higher than the wall, that is, a height of [-] meters."

Lu Chuan had carefully measured the specific height of the wall on the spot.

Lu Chuan stretched out his arm to signal: "The length of a normal person's raised arm is [-] centimeters above the top of the head."

"In this case, the murderer's height is at least 1.8 meters."

"He is 1.8 meters tall and has good physical strength. The murderer's gender can basically be determined to be a male."

"In addition, I want to do a trace evidence collection on the corpse."

Trace evidence collection?

"Are you sure?"

Liu Guodong raised this question because it is not easy to collect trace evidence.

The so-called trace physical evidence is actually extremely tiny criminal evidence.

Theoretically speaking, the contact between any two objects will leave certain traces.

For example, clothes sticking to pollen, palms touching paint, etc. will have obvious contact marks.

For some contacts, the traces will be very inconspicuous. For example, when a magnet touches an iron block, no traces can be seen on the surface after separation. In fact, the magnet must have the molecular structure on the iron block.

It's just that the molecules are too small to be seen by the human naked eye, even with special magnifying instruments.

But contact does exist.

The order of magnitude of trace physical evidence in forensic identification is obviously much larger than that of molecules.

Common trace evidence includes pollen, hair, dander, fiber, cosmetics and so on.

Trace physical evidence is not only difficult to collect, but even more difficult to analyze and identify.

Among the skills provided by Lu Chuan's system, there is a special skill card for the identification and analysis of trace physical evidence.

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 micro-evidence identification and analysis.

Even the Technical Appraisal Center of the Haizhou Public Security Bureau does not have such personnel and equipment.

Only the Public Security Bureau of the provincial capital and the Technical Appraisal Center of the Provincial Department have micro-evidence appraisal laboratories in the whole province.

In other words, after Lu Chuan successfully collected the evidence, he had to send the collected trace evidence to the provincial department for testing.

"The collection is not a big problem, but for the identification and analysis, Team Qin needs to apply to the provincial department."

Lu Chuan has intermediate surveying skills, so it is no problem to do general trace evidence collection.

"Okay, you can do a footprint analysis first to see if there is any result, trace evidence... I'll go and ask Team Qin for instructions."

After Liu Guodong left, Yang Sen and Lao Bai came over.

"Xiao Lu, have you ever studied trace physical evidence?"

Both Yang Sen and Lao Bai were first-line investigators who transferred to the current survey.

Most of the methods used are old methods and old routines.

In recent years, due to the improvement of technical level, the collection, identification and analysis of trace physical evidence is not very good at it.

But I have also heard about it, and I have done some training in this area, but the effect is average.

Lu Chuan nodded: "I have learned a little bit, anyway, there is no other way now, so I will try it as a way to accumulate experience."

Ok.

Lao Bai nodded affirmatively: "Why do we do this? Just like forensic medicine, we have experienced more scenes, dissected more corpses, and learned more."

Jansen agrees.

Why don't the police stations below, and even the criminal police brigades in the districts and counties have full-time criminal police?

Can't afford it? Of course not.

The reason why the criminal police brigade or police station below do not have full-time on-site investigation criminal police is because there are not enough cases to train on-site investigation.

Just like the Haizhou Criminal Investigation Detachment, there is no full-time trace inspection, not because they can't afford it, but Liu Guodong and a few people are enough.

The Tianzhou City Criminal Investigation Detachment has full-time on-site investigation and full-time trace inspection, because Tianzhou City has a large population and many cases, so it can have enough work to "train" full-time on-site investigation and trace inspection.

"This time we will help you, and we will also learn from this trace evidence."

In his position, he must seek his 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 seized the time to analyze the footprints collected by Yang Sen and Lao Bai.

However, just as Liu Guodong was worried, the footprints were too chaotic, with more than a dozen shoe prints superimposed, making it impossible to distinguish them.

Lu Chuan used some of the abilities in the advanced fingerprint identification analysis, but there was nothing he could do about it.

Half an hour later, Liu Guodong returned to the survey office: "Xiao Lu, Team Qin agreed, and he will go to the provincial department to apply, and then it's up to you."

(End of this chapter)