The reason
Homicide is my favorite cop show, why it's my favorite show period, is simple: It is entirely unconcerned with the normal preoccupations of the police procedural. Whodunnit is so rarely even a question, as is how was it done. It's done, we know how, we want to know why. K. refers to it as the most psychological police show she has seen, and she's right. Episode after episode delves into issues of guilt, loss and punishment. Almost every case has either no suspects or one that the cops are sure about (which is, as I understand it, how the business looks to a cop). And from the viewer's perspective, it is very, very easy to spot the guilty ones. That's never in question. The question is whether or not they can be caught, usually not from evidence so much as winning a battle of wills with them in Box, and what it will cost the cop in question to do that. Over and over the consequences of crime rather than the actual crime or the prosecution of the crime is the focus. There are lighter moments, sure, but the core of the show is the utterly banality, capriciousness and power of evil.