▁which ▁known ▁facts ▁imply ▁prohib ited ▁conduct ," ▁the ▁specific ity ▁of ▁the ▁information ▁received , ▁and ▁the ▁reli ability ▁of ▁its ▁source . ▁ ▁" At ▁the ▁end ▁of ▁the ▁day , ▁however , ▁we ▁have ▁realized ▁that ▁these ▁factors ▁cannot ▁rig id ly ▁control , [] ▁and ▁we ▁have ▁come ▁back ▁to ▁saying ▁that ▁the ▁standards ▁are ▁' fl uid ▁concepts ▁that ▁take ▁their ▁substant ive ▁content ▁from ▁the ▁particular ▁context s ' ▁in ▁which ▁they ▁are ▁being ▁ass essed ." ▁ ▁The ▁best ▁distinction ▁might ▁be ▁that ▁prior ▁to ▁conduct ing ▁an ▁evidence ▁search , ▁a ▁law ▁enfor cement ▁officer ▁must ▁have ▁knowledge ▁that ▁ra ises ▁a ▁“ f air ▁probability ,” ▁or ▁a ▁“ subst ant ial ▁chance ,” ▁of ▁discover ing ▁evidence ▁of ▁criminal ▁activity , ▁while ▁school ▁officials ▁need ▁only ▁a ▁" mod er ate ▁chance " ▁of ▁finding ▁evidence ▁of ▁wrong do ing . ▁▁ 2 . ▁El abor ation ▁of ▁facts ▁The ▁court ▁then ▁laid ▁out ▁facts ▁that ▁would ▁determine ▁the ▁level ▁of ▁susp icion / know ledge ▁that ▁the ▁school ▁officials ▁possessed ▁that ▁a ▁school ▁rule ▁was ▁being ▁viol ated ▁( exp la ining ▁in ▁a ▁foot note ▁why ▁" the ▁legit im acy ▁of ▁the ▁rule ▁usually ▁goes ▁without ▁saying ▁as ▁it ▁does ▁here "). ▁ ▁This ▁evidence ▁was ▁" su fficient ly ▁pla us ible ▁to ▁war rant ▁susp icion ▁that ▁Sav ana ▁was ▁involved ▁in ▁pill ▁distribution ," ▁a ▁susp icion ▁that ▁in ▁turn ▁" was ▁enough ▁to ▁justify ▁a ▁search