I worked at a county jail some years ago. There were several different nursing jobs that we rotated through, My least favorite job was doing med passes--there were usually 50 or more inmates on different oral meds, some multiple meds, many psych meds, and many pain meds. Because of the culture of those incarcerated, many of the inmates may have been drug-seeking for their own use, or to sell to others. We had to watch them very carefully so they didn't 'cheek' the meds. Some were angry and potentially violent, but we always had guards with us as we went into the cell areas. There were times I still felt uneasy, but I never had a problem; other nurses had been punched, spat upon, or verbally abused--but, thankfully the guards intervened quickly.
Other jobs were assessments for incoming inmates, which was more interesting (and less stressful than gathering meds for 50+ inmates three times each shift!). It was great practice for assessment skills, many inmates had little or no access to health care, so we had to be very thorough and make sure any health problems were addressed.
There was also an infirmary in the jail where we saw a combination of real illnesses and malingering. We had to determine who was sick, who was faking, and who needed to go to the hospital. Sometimes that was a difficult decision.
Overall, it was a fast-paced job that was different each day (except those horrible med passes!) Some nurses loved it an stayed for years, others got burned out quickly. Probably depends on what you enjoy and if you're comfortable with that population. The pay at our facility was higher than it was in hospitals; but it's not the kind of job you want to do just for the money--if you don't like it, it can be very stressful.