Because the suspected facts did not indicate the drugs presented a danger to students or were specifically concealed in the student's underwear, the principal did not have sufficient suspicion to warrant extending the search to the student's underwear.
The Fourth Amendment's prohibition against unreasonable searches and seizures applies to searches conducted by public school officials. What this prohibition means in a school context, though, is far from settled.
Videotaping of middle school students while they changed their clothes in school locker rooms was an unreasonable search, and students' Fourth Amendment right not to be videotaped by school officials while they changed their clothes in school locker rooms was clearly established.
A school official's general background knowledge of a student's drug abuse or depressive tendencies, without more, does not enable a school official to search a student's cell phone when a search would otherwise be unwarranted.