civil forensic

Chapter 8 Matching Fingerprints
The old desktop computer creaked and creaked.

The whistling hot air blows out from the case and dissipates in the air.

After a while, 20 fingerprints with the highest matching value were released on the right side of the LCD screen.

Jiang Yuan was not in a hurry, took a sip of tea, and then clicked on the first fingerprint to look.

In the past two days, the criminal police team, which was operating at full power because of Uncle Seventeen's murder, suddenly relaxed, and Jiang Yuan also returned to the daily state of forensic medicine—the appearance of no work.

At the same time, he has gradually become proficient in the use of the system reward he just received, "Chongqing-style single-fingerprint analysis method-bow pattern identification (lv3)".

After doing some practice with the exercise book and public information from the study period, Jiang Yuan decided to enter the actual combat: first find a bow pattern, and then find out who it belongs to.

As the first step, Jiang Yuan chose the fingerprints collected in a robbery case in Longli County, a neighboring city.

The reason why the fingerprints of homicide cases are not selected is because under the guidance of "homicide cases must be solved", homicide cases are highly valued and have a lot of resources. Before becoming a backlog, fingerprints are compared repeatedly.The fingerprints of homicide cases that are still in the fingerprint database must be extremely difficult.

If there is an unsolved murder case in Longli County, and the fingerprint of the suspected suspect is extracted, the fingerprint will first be compared multiple times by trace investigators in Longli County. Try on-site and then do the extraction. If all the attempts are unsuccessful, you will definitely ask the city-level criminal science and technology squadron for help, or you may go directly to the provincial department.

If at the provincial level, the fingerprint still fails to match, and the case is not solved, then, every one or two years, the provincial department and even the ministries and commissions will organize special fingerprint battles to conduct fingerprinting on the fingerprints involved in major backlogs. The participants in the comparison are often experts from the criminal technical talent pool or youth talent pool of the department or ministry.

Jiang Yuan has already eaten LV3 egg fried rice, so his expectations for the LV3 bow pattern identification are not so strong.

Egg fried rice was good but not shiny yet.

From this, it can be deduced that the bow pattern identification of LV3 is very powerful, but it is not supernatural.

Not to mention, the fingerprint library he can compare is limited now, and Jiang Yuan feels that it is too easy to be frustrated if he challenges the murder case with the first fingerprint he gets.

In contrast, the robbery is more suitable for the present.

On the one hand, ordinary robbery cases cannot reach the level of major cases of the provincial department; Seriously enough.The fingerprints finally uploaded to the library have a high enough correlation with the case.

Having said that, Jiang Yuan was quite surprised when he clicked on the fingerprint image of the case for the first time.

The fingerprints extracted under unknown circumstances, not to mention vague, are still incomplete, only about half of normal fingerprints.Fortunately, more fingertips are reserved, so there is a basis for comparison.

In addition, it goes without saying that fingerprints are deformed.

This situation is completely different from the fingerprints left by ordinary people clocking in to work.Without any professional skills, let alone marking feature points, it is difficult to judge which finger it is.

Of the 20 fingerprints automatically matched by the system, none of them matched as expected.

Jiang Yuan was not discouraged either. This kind of fingerprint was uploaded to the system because it was difficult for the local trace inspection to match.As for the failure of the local comparison, it may be a technical problem, or it may be that the corresponding fingerprints have not been collected in the fingerprint database.

If it's the latter, then Jiang Yuan has no choice but to hope that the bureau's fingerprint database will be larger... and what he is fighting for now is the former.

For the trace inspection police who do fingerprint matching, hard work is a must. Only hard work can have the chance to fight for luck.

Jiang Yuan closed the fingerprint comparison page and reopened the suspect's fingerprint image, this time using Photoshop.

He carefully observed the state of the incomplete fingerprints, and then began to adjust the contrast and brightness.

Jiang Yuan adjusted so meticulously that it took half an hour to slightly improve the clarity of the fingerprint.

However, sharpening the knife is not the same as chopping wood by mistake. After Jiang Yuan waited for everything to be ready, when he carefully examined the fingerprints, the direction of the lines could be seen more clearly.

Immediately afterwards, Jiang Yuan slightly adjusted the center point of the fingerprint.

Because the fingerprints are so incomplete, the center point itself is uncertain. If Jiang Yuan does not make adjustments, the system will automatically estimate a center point.

Jiang Yuan watched the direction of the lines, repositioned the center point, then put it back into the software, changed the conditions, and pressed OK again.

Another 20 fingerprints failed to match.

Then fine-tune the center point and compare again...

This time, Jiang Yuan spotted the third-ranked fingerprint at a glance.

When ordinary people look at fingerprints, at first glance, they probably think they are similar, especially if they are both bow-shaped or bucket-shaped, it is often difficult to distinguish them.

But for those who have been looking at the fingerprints, the different fingerprint features are like the freckles on the face of an old sow, and they will feel familiar after a long time.

Jiang Yuan directly clicked on the third fingerprint, enlarged it and placed it on the right side of the computer screen, and then opened the original fingerprint and placed it on the left side of the screen.

Putting the two fingerprints together, the similarities were immediately obvious.

At this time, instead of simply looking at the feature points, it is judged directly by looking at the similarity of the fingerprints.In one-on-one, the resolution ability of human eyes is much stronger than that of computers.

"We've won the match!" Jiang Yuan murmured to himself, relaxed for a while, and submitted the matching fingerprints without any hassle.

According to the rules, the fingerprints he submitted will be submitted to the experts of the provincial department. After the latter review and confirm that they are correct, and then click submit, someone will notify the corresponding frontline units, and then the local authorities will arrange arrests on their own.

Of course, it is no problem for the local criminal police to arrest people.

Jiang Yuan couldn't care less, stretched his waist, got up and stretched his muscles, then checked the time, and waited for get off work in peace.

Forensic life without corpses, simple and pure.

(End of this chapter)