A teacher discovered two girls smoking in a lavatory. D, who at that time was a 14-year-old high school freshman was one of the girls. They were taken to the Assistant Vice Principal. D's companion admitted that she had violated the rule. D denied that she had been smoking in the lavatory and claimed that she did not smoke at all. The principal demanded to see her purse. Opening the purse, he found a pack of cigarettes. As he reached into the purse, he also noticed a package of cigarette rolling papers. He immediately suspected the use of marihuana. He searched the purse thoroughly. He found a small amount of marihuana, a pipe, a number of empty plastic bags, a substantial quantity of money in one-dollar bills, an index card that appeared to be a list of students who owed D money, and two letters that implicated D in marihuana dealing. D's mother and the police were notified. D's mother took her daughter to police headquarters, where D confessed that she had been selling marihuana at the high school. On delinquency charges, D moved to suppress the evidence found in her purse as well as her confession, which, she argued, was tainted by the allegedly unlawful search. The Juvenile Court denied the motion to suppress. It held that a school official may properly conduct a search of a student's person if the official has a reasonable suspicion that a crime has been or is in the process of being committed, or reasonable cause to believe that the search is necessary to maintain school discipline or enforce school policies. D was found to be a delinquent and sentenced to a year's probation. A divided Appellate Division affirmed the trial court's finding that there had been no Fourth Amendment violation, but vacated the adjudication of delinquency and remanded for a determination whether D had knowingly and voluntarily waived her Fifth Amendment rights before confessing. D appealed the Fourth Amendment ruling, and the Supreme Court of New Jersey reversed the judgment of the Appellate Division and ordered the suppression of the evidence found in D's purse. The State of New Jersey's (P) petition for certiorari was granted.