Chain of custody is the chronological documentation showing the seizure, custody, control, transfer, analysis, and disposition of physical evidence or official records. In election administration, maintaining chain of custody for ballots ensures every voted ballot is accounted for from the moment it is cast through the canvass and certification. A break in chain of custody — such as transfer of ballots to unauthorized parties — can invalidate the use of those ballots in any recount or audit and creates grounds for legal challenge.