Dear Harish,
A few questions and comments on your post are as below:
How anyone can peep inside the changing room for women? Why the room is not secured? The privacy of the staff must be maintained. Far from doing it deliberately, nobody should be able to do it accidentally also.
Do you have a solid proof of someone peeping in the changing room? Is there a piece of material evidence? What happened when someone discovered it? Have you obtained a statement from the employee who did this misconduct?
You have written, "employee who watched a female locker room during a girl changing her cloth". Was the employee a man or a woman?
Whether man or woman, whoever peeped in the changing room, has breached the privacy. Why do you wish to let off an employee with just a warning letter? Suppose the woman employee comes to know that she was watched secretly while changing her clothes, how ashamed will she be? Have you thought of this?
Watching someone while changing clothes is nothing but perversity. An organisation should not have any place for employees who wish to satisfy their prurience. Therefore, if you have sufficient proof of the misconduct, then conduct a domestic enquiry and sack the employee. It will send a message to all the women employees that your organisation does not compromise their dignity. Secondly, it will be a deterrence to other employees with a similar mindset.
Thanks,
Dinesh Divekar