Most of the criminals are members of the struggling classes and hasn't got the money nor the culture to invest in social frames, nutrition, sports etc. which results in healthy and balanced individuals = "beauty". They are also inclined to use alcohol and drugs, which does not make the face look healthy. It's as simple as that.
BTW: how goodlooking would YOU be at the precinct after they hauled your ass in?
The whole point is, most of us don't behave in a way to have our asses hauled in. (BTW: They'd need a truck for mine, thank you very much.)