In any criminal or administrative investigation, you have the absolute right to consult a representative of your choice before making any statement, oral or written, regarding any matter that could lead to punitive action.
For an exclusively administrative matter, you may consult with your representative. However, you should talk only to someone from a law office for any matter that has potential criminal liability, such as any use of force. There is no confidential communication privilege between you and a union or other representative.