Legally, Does My Child Have Rights?

[TheeBadOne]

When you send your kids to school, you are giving the school the same parental control over your kids that you have. In effect, they are the parent for your kid until you take custody of them back at the end of the day. Most here seem to understand about the locker issue (school can search any time/reason). The school can search students if they have reasonable suspicion (a much lower threshold than the probable cause one Police usually operate under). Now, because school admin isn't trained how to do a search, they can request professional assistance, in the form of a Police Officer (and in this case, it sounds like the School Resource Officer). The school can ask for this professional aid just the same as they can call an ambulance for your kid if they break an ankle. They don't have the expertise/training to deal with it, so they request assistance professionally.
In closing, this is not "speculation" or my personal opinion on how things should be, but rather how it actually is.
So much of what is posted on the net is the summation of a persons emotional bias. That's not a good direction to follow, especially if one is seeking legal advice.

All the best