What is "knife residue"? Do they mean blood splatter from stab wounds?
Yeah, 'knife residue' doesn't make much sense, does it refer to stab wounds which were caused by a knife (possible the knife in question), does it mean bits of metal broken off of that knife,...?
Also, breaking down the prosecutor's argument is the job of the defence attorney, not of an expert witness (except if it's different in China?). But then again, it's just a manhua, I should really just relax.