Can a middle school principal or police officer legally search a students backpack?
School children have a diminished expectation of privacy in a public school, and since their lockers are school property, they essentially have no privacy interests in their lockers or their contents. In order for a search of the backpack to be “unreasonable” in the 4th amendment context, your son would have to have a subjective privacy expectation (he would personally have an expectation that the backpack contents would be private) and an objectively reasonable privacy expectation, which means that the general population would think that his expectation that the contents are private is reasonable. Given the pervasive surveillance at a public high school, most courts would probably assume that he doesn’t have an objectively reasonable privacy expectation. Moreover, regulatory searches are not “unreasonable” if they are conducted under a neutral protocol. That’s why everything you carry onto a commercial aircraft can be searched, or why the cops can setup a sobriety checkpoint on a road
