tier be released with the push of a mechanical bar. with so many inmates and so few officers, the opportunity for violence looms large. the only visible deterrent is the lone armed officer who constantly patrols the gun rail which overlooks the tiers. >> my job is to walk around, give coverage to the other officers, watch the inmates movement. make sure there's no fights, nothing going on in the cells. of course, you look for different things like weapons, visible things. >> by contrast, contemporary prisons control inmate movement safely and remotely with the use of electronic doors.