As for the judgment about the young male, it is partly based on the victim's weight.
The victim has a slightly overweight build, weighing about seventy kilograms.
The killer was able to pin the victim against the wall in mid-air and fix his arms and ankles with a nail gun, indicating that the killer is very strong.
Generally speaking, female killers do not possess such strength.
On the other hand, when the killer stabbed, although his hand shook, and he was inexperienced, each knife wound was relatively strong.
From these knife wounds, it can be observed that the suspect's wrist is quite powerful.
In most cases, the probability is higher for males.
Of course, Lu Chuan's judgment is only a probability.
We cannot exclude individual cases where some females are physically strong and have a robust build.
The suspect could also inflict similar injuries.
