174: Chapter 167 The real case 174: Chapter 167 The real case The small lecture hall of the Qinghe Bureau is located on the first floor of the office building.
The indoor plants are somewhat withered, but no one cares.
It, along with other unimportant departments, keeps its doors wide open, welcoming guests from all directions, including the uninformed public and police officers from various places.
However, the usage rate of the small lecture hall is still very high.
As a bureau that values form over substance, the Qinghe Bureau pays great attention to organizing and reporting various activities.
Otherwise, its existence would be almost meaningless.
Today’s lecture hall was also filled with quite a few people, and then a tall young man was speaking slowly as if he were a university student giving a presentation.
But the atmosphere was somewhat different.
The young police officer wore gray shoulder straps, indicating technical police, with a full police uniform that looked good on him.
Although he wasn’t the type of popular teen idol star of the moment, he still had the appearance of a genteel and sunny young man, further enhanced by the uniform.
Sitting at the podium with a serious expression and speaking with ease, almost any photo of him could be used for publicity.
Jiang Yuan also put on a pair of plain glasses for this training session even though he didn’t have myopia, as his master had suggested that wearing glasses would be better since he has a youthful face.
Meanwhile, the police officers sitting in the audience looked at the projection screen with serious and solemn expressions, their facial muscles slightly twitching and their eyes wide open, straining to pay attention.
The first round of 20 similar fingerprints were displayed on the right side of the screen in a vertical column.
On the left, three-quarters of the screen displayed the fingerprint with the highest similarity ranking in full detail.
“Alright, let’s take a look at the fingerprints returned in the first round,” he said.
With one hand, Jiang Yuan pushed his unfamiliar glasses up the bridge of his nose, and with the other hand, he clicked the mouse, enlarging the fingerprint on the left to full screen.
The fingerprint projected on the screen was also quite clear.
“Okay, here we have an exclusion point,” Jiang Yuan said, clicking twice to further magnify the fingerprint.
He then drew a small circle on the right side of the fingerprint with his mouse, indicating it to everyone.
For fingerprints that have been matched, the standard is not how many feature points are consistent, but whether there are any inconsistencies among the feature points.
It’s easy to understand that if two fingerprints are the same, in theory, all of their feature points should be identical.
So, if there is one feature point that doesn’t match between two fingerprints, it can be determined as an “exclusion.”
That is to say, the two fingerprints are not the same, not from the same finger.
Following this line of thought, Jiang Yuan eliminated two similar fingerprints in a row.
At this moment, Cao Keyang from the Qinghe City Bureau, who was sitting in the front row, said, “Teacher Jiang, maybe we should display both fingerprints side by side for comparison.
It’s not very clear seeing them excluded directly .”
Jiang Yuan was quick to react, clicking twice to display both the original and matched fingerprints side by side on three-quarters of the left side of the screen.
“My apologies, I was thinking about speeding up the process as the first few fingerprints can be eliminated quickly,” Jiang Yuan said sincerely.
Cao Keyang felt an inexplicable sourness in his heart and hastily replied, “No problem, it’s not an issue on your end.
Since we’re lecturing, it’s just better to go slower and clearer.”
“Alright, I’ll keep that in mind,” Jiang Yuan nodded and continued, “Let’s re-examine the first two fingerprints.”
Then, Jiang Yuan performed the same actions, circling on the right.
What was different this time was that he also made a circle on the left.
Consequently, the audience finally uttered coherent “Oh” sounds.
Seeing this, Jiang Yuan kept up the good work by circling the second and third fingerprints as well, before also dismissing them.
The “Oh” sounds from the audience slowly decreased.
Technical staff with fingerprinting skills below level LV1 started to feel a sense of sourness in their hearts—it was an indescribable feeling.
They finally realized that Jiang Yuan had memorized the entire set of original, complicated fingerprints.
So, the exclusions he had done were purely from memory.
Without needing to compare, having the original pattern in mind means that exclusions or comparisons can be done very quickly.
This wasn’t actually that remarkable.
If one had started preparing a few days in advance, spending a considerable amount of time, everyone could remember parts of the fingerprints…
But who would go to such lengths?
Such intricate fingerprints couldn’t possibly be expected to be memorized, one would assume.
Even the fingerprints themselves would probably get annoyed, right?
It was possible for a trace examiner who had focused on a particular difficult fingerprint over many years to gradually memorize its features, but even then…
While some people were lost in their thoughts, Jiang Yuan had already excluded three more similar fingerprints.
Then, Jiang Yuan said, “At this point, it is generally recommended to review all 20 fingerprints.
But, we won’t do that today because as the similarity decreases, the chances of finding a match become very low…”
Cao Keyang was stunned.
The audience was stunned.
Why did this feel so familiar?
It was like the time when they were still in school, looking down to pick up a pencil, only to be completely lost when they looked up and heard the teacher’s words again.
Even the last sentence was the same: “I won’t go over the next steps, as they are quite simple, so let’s skip them, but from this we can deduce that…”
Jiang Yuan showed no intention of pausing.
After the first round of fingerprint screening, Jiang Yuan brought up the original fingerprint again and said, “Now let’s mark the characteristic points for the second round.”