I THINK you can actually get a job through the state (PennDOT) doing the same thing but what I do know is working for a police department you will need to go to a class that is at least two weeks long but my guess is your department wouldn't send you to it unless they 1. Needed/wanted one and 2. You had been working for the department for a few years. If you're working for a police department the pay will be whatever normal pay is. It's just a specialized assignment and in some smaller departments you may not even do it every day.
We had a member on here that was one but he isn't very active anymore. He'd be a better source than me. The tattoo thing would depend on the department. What's your criminal background like (drug use, tickets, arrest etc.)?
"Knowing what you stand for limits what you fall for"