A qualified detective.
It means that when analyzing, not a single detail can be overlooked.
The points Qin Fei mentioned are vastly different from Huang Zhao himself.
Even though Huang Zhao knows medicine and takes care of his health, at over seventy years old, he still has a rosy complexion and appears quite healthy.
But a man in his seventies can't possibly have the vigorous energy of someone in their prime.
Chen Xiao hasn't forgotten this point.
The reason he still considers Huang Zhao as a suspect is because he has interacted with Huang Zhao extensively.
He is well aware that although Huang Zhao is elderly, he is indeed very healthy.
Health implies that one's mechanical skills are still good.
The main point is that there's a difference between elderlies.
Some septuagenarians are bedridden, unable to care for themselves.
Yet, some in their seventies are still active, working from sunrise to sunset.
