I know I poked the bear here to begin with, but fuck it. Moral opinions on tatoos aside (beyond me wondering if you're a cop, concerned parent, concerned parent to cops, or a concerned cop), most of the tatoos I've seen were on people who were more than happy to explain why they got stabbed by a professional. There are plenty of posts on the internet explaining why some of the more out-there tatoos are the way they are (say, morse code, or a waveform of something important). You don't really have a problem with tatoos so much as a problem with socializing with literallly anybody with a tatoo art in general. It's artwork. It's personal artwork engraved into your very flesh. It does not owe anybody any clarity on why it exists beyond personal enjoyment.
and most importantly, it's art that would be at least very hard to launder money with, if not impossible