Obstruction of Justice

The state of Tennessee. The question I need answered is....Does a school principal in the normal ordinary lawful course of his business in the school environment obstruct justice if he is conducting an investigation into a violation of school board policy and does not stop his investigation when the police ask him too stop because in their opinion the school policy violation is also a violation of criminal law although no arrest warrant has been issued nor an investigation by the police is in progress or judical proceeding is pending.?