I suppose felons could break many of the stereotypes by simply heading to Macy's and picking up a few cardigans and decent slacks. But then many would have to nix the meth-head look, the wild look in the eyes, the rings/spikes through new orifices, the ankle-draggin' clothing, the "walk" and the "talk" (demeanor that can be strongly suggestive of where their influences have come from).
Nothing's for certain, in this life. But, as individuals, ignoring potential indicators can be one of the most foolish things we do. No other animal does that. Ignoring a heavy grouping of potential indicators in a single person or group of people can be one of the last things we do. It is what it is.