Snap shots are dropped at random but still in certain rooms. I have created a map called "I Have This Condition" with easy access to all rooms for collecting all snap shots so no need to waste time with Pre built maps. the map can also be used to grind out some of the other achievements.
Simply load the map run around until you find the snap shot then exit. do it again until you have all snap shots.
I've made a few changes to the map to make it easier to grind out some of the other achievements. The padded cell is now near the main block so if you end up there instead of the red cell it's easier to grind from. there are now 50 metal detectors out the back of the red cell for sabotaging. Add a few more cooks and a couple of more guards.