Generally, Article 32 preliminary hearings are not open to the public in the same way that a court-martial or a civilian trial is. The proceedings are considered official military business and are typically closed to the general public and the media. The primary participants are the Preliminary Hearing Officer (PHO), the accused and their defense counsel, the government counsel, the witnesses being called, and necessary court personnel like a reporter.
The rationale for closing the hearing is rooted in its nature as a preliminary investigation. The hearing may involve the presentation of sensitive, classified, or highly personal information. There is a strong interest in protecting the privacy of the accused and the alleged victims, especially since the hearing is only to determine probable cause, not guilt. Publicizing allegations before they have been substantiated for trial could unfairly damage reputations.
However, the Manual for Courts-Martial (MCM) does grant the convening authority the discretion to open the hearing in certain circumstances. The convening authority must balance the value of public access against the need to protect sensitive information and the privacy interests of the participants. This discretion is rarely exercised, and the default practice is for the hearing to be closed.
It is important to distinguish this from the trial itself. If the case is referred to a court-martial after the Article 32 hearing, the court-martial proceeding is presumptively open to the public, consistent with the Sixth Amendment right to a public trial. The closed nature of the Article 32 hearing is specific to this pretrial investigative stage and reflects its unique purpose within the military justice system.