you said they asked for permission. that's probably cause they couldn't legally do it without it. see the police won't tell you that up front, they won't just say "we can't search you unless we ask you legally, and you do'nt have to consent". they want to pressure you into saying yes and they won't advise you of your rights--they use it to get the upper hand, to find something incriminating. but if you agree to let them search you and they find anything illegal on anyone, it's probably just cause for them to search everyone. not saying that it ain't fucked up cause oklahoma fucking sucks and so do police, but yeah contact your lawyer immediatley.

ps--rent a cops have no legal authority. if any rent a cops violate your rights all you got to do is call the school board or the company they're working for and bitch to holy hell about it.