As an engineer for a seller of technology to the Bureau of Prisons, I visited Lewisburg Federal Pen maximum security prison & on the other side of the hill, Allenwood Fed Pen. Difference of night & day.
While entering Lewisburg, a "hot" inmate was brought back in. He had testified in court someplace. He 1st had to stand in a circle between the front gate & the main building entrance for some paper work processing. Then he was brought inside & also had to stand in a similar circle <2' across ... in chains & shackles the whole time so there was lots of shuffling.
Metal detectors can detect eyelets in sneakers. No metal of any kind was allowed. I stupidly forgot about an aluminum comb in my bag.
We were given a tour of the open areas of the prison. Inside, in front of the main guard station, there is an area called the red top which is just an area on the floor painted red. In that area only 3 prisoners are allowed to be on at one time ... so the guards can see further out and so to minimize attempts to break into the guard station. The guard station was behind a few inches of break proof glass of some kind.
I went thru about 3 levels of basements used to move hot prisoners & for "suppression" squad to march thru in case of trouble ... guards wearing hob nailed boots described as doing some kind of goose step to maximize the noise of their approach.
I also was 1 of 2 to visit a guard tower. Interesting to see very large bore rifles ... clearly not intended to shoot bear.
I also learned why keys have metal sheaths that fall over the business end. These inmates may have gotten caught, but some are highly intelligent ... with so called photographic memories & could make a duplicate key just seeing a key, once. Of course, they do have the time. :\
At Allenwood, a minimum security prison, we drove thru a golf course separated from the prison grounds by only a chain link fence. There we were served by & ate lunch with the prisoners. The worse thing there, was avoiding stepping in goose crap all over the sidewalks (that time of year). The prisoners lived in kind of separate single story dorm-like buildings. Better not get caught playing even poker tho, else they would get shipped across the country to higher security prisons. We all bought "Club Fed" T-shirts in the prison book store.
My prison experience ... sobering