The majority of the mug shots (that you’ll never see, because most places don’t even care enough to release them) don’t have the arrested in a jumpsuit or with placard. Modern day suspect lineups use those mugshots to generate ‘look-alikes’ so that the lineup isn’t one black guy and four white guys and thus completely ridiculous in terms of a victim identifying the actor in a crime. The mugshots need to be of them in civilian attire for the same reason that you wouldn’t put one guy in the lineup in handcuffs.