the prob is that if you're lucky, you'll get 1 tip from a kid about the drug, gun, whatever.
if the administration doesn't act - and that kid sells drugs to a kid that dies... then everybody gets shitcanned, lawsuits, etc.
if they do act and the kid is guilty, nobody sues cause the kid is in deep shit.
if they search and find nothing, it's a case by case and they're better safe than sorry.
In the school I was at, they'd find a gun per month on kids - grade 6 to 8. As a teacher who had to leave my own piece locked in trunk - I was damn happy the police were searching and expelling kids. I was more worried about one of their immature, emotional 12 year old minds going blank and starting shooting, than I was about their rights.
Wrong, yes. But it is what it is.