I'm a RN in an acute psych facility. I think that it is extremely important to search EVERY patient on admission!! Although they are each wanded when they come through the door, this can miss things. We have them go to a room and remove all clothing. This is an external viewing of their body. In addition to searching for items; we also are marking down all scars, scratches, cuts, burns, bruises, tattoos, & etc. We search and wash everything they are wearing & all clothes they brought with them. This is to hopefully destroy any pills or drugs they may have sewn into their clothing.
I have personally found pills taped under breasts & bellies, lighters, matches, needles, inhalers, razor blades, and even a knife once during the safety check. And this was all after the "wanding".
If facilities aren't doing this now, then they should definitely step it up. We do this for every patient. I know that it's hard to believe that a 65 year old granny would come toting pills or marijuana, but you would be surprised! Psych patients are mentally unstable. They are sometimes impulsive, oppositional, drug addicted, or just plain scared they won't get their benzos that they have relied on for twenty years. Best to check everyone and everything they bring along thoroughly to ensure their safety as well as your own.