Education Law Questions? Ask an Education Lawyer
I'm sorry to hear about your situation. Unfortunately, and as strange as it may seem, the police are allowed to question a minor without anyone present and without parental notification. Here, because the investigator is working for the prosecutor's office, the analysis would be the same as it would be for a police officer, since he is acting on behalf of the government. Your son would have the same rights as any adult being questioned...such as the right to remain silent or to ask for an attorney. But he does not have a right to have a school official or a parent present.
A few years ago, the Supreme Court considered the same issue. They did not find that a minor couldn't be questioned at school...just that the student may be entitled to be read his Miranda rights based on age:
If he were to have made incriminating statements during this interrogation, then he might have recourse in a criminal case to have the statements excluded if he were not properly Mirandized or if the statements were coerced. But from a civil standpoint, he has no rights other than the standard rights that everyone has. He could have refused to talk to them, but if he didn't, they are allowed to speak with him even without an adult present. I know most parents are surprised by this, as it seems intuitive that a parent should have to be around for serious issues involving minors, but the courts have clearly ruled that it is not the case. Sorry I can't give you better news.