Sheesh,
My godson (never been to prison, and probably never will be), is running out of places for tattoos and piercings. Every single week I get a picture from him of his newest tattoo.
This will probably get deleted - maybe - but, I have a friend who was in prison (for stupidity, but everyone managed to get away except him), and while in prison, he tattooed a small fly on his private part. He said sometimes it was a small housefly, sometimes it was a big old horse fly.

(he was my girlfriends hubby). Guess you have to pass the time somehow.
All my kids have tattoos. Both boys and my daughter. Of course, all three have pierced ears too.
My godson, the one with all the tattoos, is a licensed tattoo artist. He is his own best customer.

Actually, he has made a pretty good living at it for 20 years almost.
I always look for certain kinds of tattoos. (a lesson from nursing school). Between the thumb and first finger, between the knuckles, the top of the forearm. Those are all possible injection sites for junkies, and the tattoos cover up any track marks. One of the first lessons in ER clinic class.
Beth