Yes, metadata can be a primary and legally sufficient means of authenticating digital evidence at a court-martial. Authentication is the process of proving that a piece of evidence is what it purports to be. For digital evidence like an email, a text message, or a photo, the associated metadata is a digital fingerprint that provides detailed information about its origin, creation, and history. Military Rule of Evidence 901(b)(9) specifically allows for authentication through evidence describing a process or system that produces an accurate result.
A prosecutor will often call an expert witness from a digital forensics unit (like a CID computer crimes investigator) to authenticate the evidence. The expert will testify that they extracted the digital file and its associated metadata from a device. They will then explain what the metadata shows—for example, that a specific photo was taken on a specific date and time, with a specific phone’s serial number, at a specific GPS location. This testimony establishes that the evidence is genuine and has not been altered.
A defense attorney will challenge this by cross-examining the expert on their methodology or by hiring their own expert to look for signs of data manipulation. However, properly extracted metadata is considered very reliable evidence. In many cases, especially if the evidence is straightforward, the prosecution and defense may simply agree to the authenticity of the digital evidence through a formal “stipulation of fact,” which avoids the need for expert testimony on the metadata altogether.