Most of the time it doesn't get to court. It is used to authenticate evidence, in this case photos, before the case gets to court. A large number of departments have switched from film to digital for the forensic photos. With film if someone questioned the authenticity of a photo then the negative could be viewed. In the digital age, that digital negative can be authenticated as well. It is often used by law enforcement, insurance companies and news agencies. Canon has developed such software which is available for certain models of their cameras. I can't speak to other programs out there. Forensic photography is not my field.