After finishing watching this movie with a friend, I told my friend that there is a scene that wouldn't have work. This is a scene where Detective Q use chalk with one hand. To make it short Qin Feng (protagonist) say that if he handed the chalk to the cop they can determined which hand Detective Q uses. I said that Qin Feng grabbed the chalk with his bare hand ruffly that would have smudge the finger print. But then my friend said that's not it, each finger are different. I ask for explanation and they said that each finger is unique thus they can use the skin left on the chalk to tell which hand uses it. I said that is not how dna work but my friend was not accepting it and was still trying to explain to me. So random people on the internet going by the little info that I have given, tell me if I am right or wrong. I am going to sleep so I wont be responding but I look forward to your response.
that only works for fingerprints, not dna. also i know the movie you're talking about. i love both the movies. and was hoping to see the third one this year. but it got cancelled due to covid. im curious what mess they'll make in japan
If you don't know they're not exactly unique as profiler would get multiple close matches (it doesn't help that fingerprints sample are incomplete in most cases) to which they have to develop their suspects using other data such as their alibis and motives.
I can't imagine chalk retains fingerprints very well…… I mean, maybe? It would be an incomplete print at the most, so I doubt they could get anything from it. But iirc, in that scene Qin Feng saw which hand Q uses with his own eyes through the window, so it kinda makes this moot. (Also, was that guy really Q?? the ending was confusing for me ;-; )