Heck, they don't always need a hole in a fence. I delivered a couple of dental chairs to Folsom in the '70's. Brought them in with a Chevy van. The boxes were plenty big enough to lay two or three cons in each. The guards lifted the hood, which was fairly tiny, took off the hub caps, checked the glove box, mirrored under the chassis, but never looked in the boxes, either coming in or going out! They had a nice old inmate help move the boxes into the clinic. I asked a guard what he was in for, they said he murdered his family, cut up the bodies and buried them in his back yard. Nicest old grandpa kinda guy you would ever want to meet.