If You Don't Deserve It
Life isn't fair and sometimes we get caught up in the drama of office politics. Discipline is often given out because of convenience or politics. Since history is written by the victor, not all reprimands are created equal. Words have meaning and how the investigation is written leads to the outcome; it's a form of bias. The subjective standard of 51% has bitten many an officer for no good reason other than it made the agency look like it took care of a problem. In today's world, a mere accusation takes on the form of the 1800s Napoleonic Code of guilty until proven innocent.
During an internal investigation, you are usually the last person interviewed. You will be given the opportunity to read all witness statements against you. Make sure you do, because that will let you know where you stand not only in terms of the severity of the complaint, but with the people involved. Especially if others from your agency are involved. Obviously, you will find out quickly who is representing the truth and who is not. Take your time reading the material and take notes while you read so you can bring them up during your interview.
Though your interview is driven by the questions of the investigator, there is always a point where you are asked if there is anything you'd like to add. If you haven't had an opportunity to address some key issues in the testimony, it's at that point you should whip out your notes and make sure all your concerns are put on record. If you don't put them on record, they don't exist, which is especially important if you are already considering an appeal.
If you are given a reprimand, you will be asked to sign it. Failure to do so can be seen as an act of insubordination. Signing doesn't mean you agree with the outcome but that you received it. Instead of not signing, sign and add, "I do not concur with the findings." If you are going to write a rebuttal letter, you can also state, "I do not concur with the findings. Please see my rebuttal letter."
A rebuttal letter becomes part of the discipline packet. This is your opportunity to write a detailed response to the complaint and include your concerns, especially those from the notes you took while being interviewed. Though your agency has the final say, you are at least guaranteed that your side of the story is presented.