A slow-acting virus, like mad-cow disease, is introduced into the human body via the tattoo needle and makes its way to the brain, where within a few years it causes the afflicted to steal cars, burgle houses, and assault people.
To me, tattoos shout it out loud and clear: Yes, I am a DUNCE!
There may be a use for those males cabranos in prison. Like in the 'Dirty Dozen' movie. Get the worst and give them real hard military training for a few months to learn discipline. And then send them to Afghanistan to take care of the Taliban. Maybe 30,000 could be offered pardons if they are successful and get a new career.
Like MS-13, The Lords and other gang members. This idea will scare the hell out of the jihadis. They have no soul and will slit the neck of them if enemy.