Dear Ms. Anderson,
Thank you for posting your request on History Hub!
If this is a past event, there may be an investigation in the Inspector General records of the unit or command in which the enlisted person served. If it went to trial, there would be a courts-martial case file in the Judge Advocate General (JAG) records of that branch of service depending on the severity of the charges. Location of those files depends on the year and service.
If this is a recent event, we suggest that you review Requesting Army Courts-Martial Records; Air Force JAG; Monthly Marine Corps Court Martial Reports; and Results of Navy Trials websites for how to obtain the information about charges filed against an enlisted person for the applicable branch of military service.
We hope this is helpful.