The zero tolerance policies in schools does not really violate the students rights because the zero tolerance policies usually stop the student from doing things that are bad and prevent them from bringing weapons into the school or also prevent the student from bullying other people.
So that way the zero tolerance policy does not violate the students rights.
Minors have some rights but minors do not have as many rights to do things as adults do so the policies put in place and the control that the school does for the minor does not violate the students rights in anyway.
The zero tolerance policies are a natural consequence of the student being in possession of contraceptives and other things that are banned from the school.
So if the student doesn't want to be in trouble for the rule they broke they should follow the rules of the school and not bring any weapons to the school, do not bully anyone and follow the schools rules and the student will be okay.
Break the rules and if they are severe enough the cops can be called and the student may be arrested for the offense but if it's a more simple rule breaking then they can be suspended from school and then expelled from school.