First and foremost, wait until all the facts are in. When the investigation is complete you will be able to render a fair and just decision. No one wants to be pre-judged. While this individual may be guilty there is always a chance that things are not exactly as they appear. Perhaps the leader did some of the things he is under investigation for, maybe he did something even worse, or maybe he is innocent.
When the investigation is complete you know the facts and can clearly articulate bullets for the Relief for Cause Report. This is also the best point in time to determine if a relief action is appropriate. Let the emotions of the situation fade and make the decision to relieve based on the facts.
For more information about Army evaluations and for over 1,000 example bullet comments, read The Evaluator: The comprehensive guide for preparing evaluation reports