One of the requirements, as far as there are such a thing, is that the villain be in the process of doing something wrong. Otherwise they aren’t much of a villain. Lately the trend has been to try and explain why and how the villain justifies this wrong-headed behavior. But there isn’t always a justification sufficient for a normal, sane person: Hitler and his did some awful things and I can’t see anything making that seem like a reasonable action. Rape is never a reasonable thing to do — but it still happens. For the purposes here, we’ll leave off justifications. Somehow, someway, the villain is getting something out of it.
The crime also has to in some way impact our hero. Preferably, the crime has to be something the authorities can’t stop (lack of evidence, etc, which implies a lucky or intelligent criminal), or won’t stop (corruption, implying a powerful, and thus really interesting criminal). In different settings — the 1950s for example — evidence is a much higher bar. DNA wasn’t an issue for criminals back then. To paraphrase John Mulaney, “You pretty much just had to not be there when the cops showed up.”
Thus, I find myself with a current dilemma in setting something in the present day… because there are cameras everywhere, DNA everywhere, fibers… everywhere. Ballistics are taken of many guns off the assembly line. Even without registration, tracking a gun… blah. Without some sort of authority to help a perpetrator, there are any number of Dues ex Machina ways the person could get caught.
And you really want the hero to do the getting, not a hairball…