These days, tattoos aren’t just the hallmark of an outlaw or a criminal. In fact, they’re more likely to denote a barista or frat boy than they are a scourge of society. But in prisons and the criminal underworld, tattoos convey secret meanings that let other criminals know who exactly they’re dealing with.
via: Miami Ink Design
Take a look at these freaky meanings behind tattoos and keep an eye out for them when sizing up strangers.