I worked in forensics for 15 years. The media rarely gets 30% of the facts straight in their reports. When I would meet clients at the probation officer's office, I would look at the map of where the sex offenders and violent offenders were, and they are EVERYWHERE.
Nick, I understand the tattoo culture. Tattoos are accepted in most circles now, but neck, head, and face tattoos are usually associated with criminal or drug affiliations, as are knuckle tattoos.
My advice: don't invite them into your home, and you will usually be fine. Most criminals are creatures of opportunity. Don't give them the opportunity. Random violence is rare. 99.9% of the time assaults and murder are relationship based.