Within the urban culture, "cholo gangster" often refers to a street gang member who is of Mexican or Chicano heritage.
The term comes from the barrios of Los Angeles, and historically it is associated with a particular look: baggy pants, plaid shirts worn Paisley wise around the headband-tie worn at all times at night during hours when one might be out shopping and in general 'not quite daytime but not fully dark' time etc..
However it should be noted that this word is one which may cause offense so care should be taken when using it.