A chain of custody is very important when performing forensic audio and video authentication. It is a documentation of the persons who have been in control or custody of a piece of evidence since it was created. A chain of custody begins when the evidence is removed from the devise that created it.
When we recover evidence from an audio or video recording system, we begin the chain of custody. This is initiated by listing the devise name and the digital title of a digital file or recording that was removed and to be used as evidence. The persons names who were involved in that collection of evidence are listed. The date and time is also listed. Any other scientific observations made during the extraction and collection of that evidence.
A chain of custody document should accompany the evidence at all times. Copies can be made of the chain of custody and signatures included. A chain of custody log should be official and include all information to document the integrity of the audio and video recording.