Okay, so... chapter 28 huh? This is a fascinating glimpse into the philosophy regarding crime and punishment of... what I am going to go out on a limb here and hypothesize is mainland China? I am not certain of the point of origin, it could be Hong Kong or Taiwan, but the main ideological dispute between the two leads seems to be "well rats, even if we can prove he did the murder he won't get the death penalty because he is the surviving parent and needs to take care of the child" and even the one saying that doesn't mean we kill him ourselves is saying "even if the law is flawed I must follow it" which suggests that barriers put in place that stop a state-sponsored execution are considered an unfortunate limitation or loophole of that legal system.
which is a wild thing to be true for several reasons, first the implication that a child would be left in the home of a murderer, or that the murderer would need to be kept alive to provide financial support, secondly that execution seems to be the only outcome those officers would consider True Justice, and thirdly that this is the example being used to set up a vigilantism plotline.
I get that murderers getting executed is a popular "eye for an eye" policy with people, but that doesn't make it a good idea, it has pretty consistently failed at building a better, safer society for as long as human history has existed. And is China really so hostile to the idea of social services like adoption or the like that a murder dad needs to remain the caregiver of their child?