Any search of students' persons or property is a prima facie violation of their privacy. Whether it is legally justified depends on the circumstances. Students have a reasonable expectation of privacy in their lockers even if the locker is technically school property. Schools should not undermine this privacy by declaring that students will have no privacy in their locker and therefore be subject to search at any time for any reason. Searches that involve allegations of criminal conduct are more serious than searches involving allegations of transgression of school rules.
More due process is required for the former than for the latter.
Similarly, the more intrusive a search, the greater the justification that is needed for undertaking the search, both in terms of the need for objective evidence for initiating the search and in terms of the seriousness of the suspected infraction. For example, a search of a locker requires less justification than the search of a handbag which in turns requires less justification than the search of a person. To justify conducting a more intrusive search, one needs more objective evidence for suspicion, and the alleged infraction must be more serious. I note that this case was decided before important jurisprudence on the section 8 Charter right by the Supreme Court of Canada. Though this case remains a the leading case on point, in my view, the reasoning of the court is open to question.