They make cooks and teachers fill in. So you believe it.
Technically, anyone in the Bureau of Prisons Department of Justice has to be trained in weapons and tactics. This is whether you are a guard or work in the business office as an accountant. They all go to the same training that the border patrol goes to.
I am speaking from the experience of a sibling who works at The Big House in Lewisburg, PA. His wife is a retired accountant of the BOP at the same location. She had to do a week in the guard tower holding an M16 a few years back. My brother is required to own a hand gun and to be proficient with it. Hw works on the outside of the wall in the administration building.