Tattooed men who are not behind bars are either latent criminals or degenerate aristocrats. If someone who is tattooed dies in freedom, then he does so a few years before he would have committed murder.
If nothing were left of an extinct race but a single button, I would be able to infer, form the shape of that button, how these people dressed, built their houses, how they lived, what was their religion, their art, their mentality.