Things that solve crimes

After wiping the inside, wipe the outside. There are not many things to wipe in the room, but mostly daily necessities.

The survey work may seem like a big deal, but it is all trivial matters.

Behind the support of completing these trivial tasks are countless resources, large and small.

Just like wiping DNA and fingerprints, there is no advanced instrument in the world that can detect DNA and fingerprints within a certain range.

For example, when brushing fingerprints, the tools and powder used when brushing are different depending on the location of the attached material.

Sometimes chemical reagents are used, and these chemical reagents are also different.

Therefore, if an on-site survey or trace inspection personnel wants to obtain a fingerprint, they must first determine where the fingerprint may exist, and then borrow light or use tools to observe the location of the fingerprint.

The last step is to use powder, iodine fumigation or silver nitrate or chemical agents to brush the fingerprints.

And taking DNA is much more troublesome than taking fingerprints.

Fingerprints can be seen, but DNA cannot be seen by the naked eye.

Generally, on-site investigators or police officers rely on guesswork, packing everything from the victim's common daily necessities, water cups and towels... to clothes and quilts that are less likely to be found.

How much does it cost to make DNA? The reagents alone cost 100 yuan, which shows how high the cost is.

Of course, it would be different if a big boss took action.

The boss usually thinks from the perspective of the suspect, guessing the other person's behavior and activities, and looking for places where DNA may be left.

In this way, the possibility of scratching will be greatly increased, and the cost will be reduced.

After Qin Henian finished wiping the room, it was already dark and the autopsy results were out. He was sorting the evidence box.

Fat Surveyor held his cell phone and read the message sent by the forensic team. The deceased, Fang Ye, had been stabbed several times, one of which even hit a major artery. In layman's terms, he was hacked to death.

Qin Henian raised his eyebrows. He was chopped to death. It seemed that he thought well. The murderer must be stained with the victim's blood. In this case, "wipe the bathroom again."

"... wipe it again?" Fat Surveyor was stunned, then looked at the evidence box next to him, "There are hundreds of copies here, wipe them again tomorrow?" If there are more, he is afraid that the laboratory will go crazy.

It was only after spending an afternoon with Qin Henian that he understood the team leader's easy-going personality that he dared to say this.

Qin Henian pointed to the evidence box, "Most of them are useless here. The fingerprints have been processed cleanly, and [-]% of the DNA cannot be extracted."

"The bathroom is different. The murderer cleaned the blood stains in it and stayed there for a longer time, so the possibility of extracting DNA is higher."

The young man nodded stupidly, "But we have already wiped the bathroom." Why do we need to wipe it again?

After looking at the young Xian Kan's eyes, there was a clear gaze that can only be seen by college students who have just entered the society. Qin Henian's dead eyes, can you see what you are wiping?

Fat Xiankan slapped young Xiankan on the head, "What nonsense are you talking about? Just wipe it when the team leader tells you to."

Young Xiankan covered his head and looked at Fat Xiankan with an aggrieved look, "Why did you hit me?"

Fat Xiankan sighed in his heart, this fool, even if the team leader has a good temper, he can't offend people like this.

Ignoring the "fighting" between the two, Qin Henian came to the bathroom with the tools, and the two quickly followed him.

Wiping the things in his hands, Qin Henian suddenly asked, "Are you master and disciple?"

Fatty Xiankan smiled and said, "Yes, this kid was assigned to me as soon as he graduated."

Qin Henian thought to himself, no wonder he was so skillful in patting his head. He glanced at the young man from the corner of his eye again. This kid must have been patted frequently!