used to determine the authenticity of specific voting transactions. • In many states, voters must sign a poll list before casting their ballots on election day. The validity of a particular voting transaction can be determined by comparing a voter’s signature at the polls to the signature on his or her registration card. Persons responsible for casting fraudulent votes may be identified by comparing the poll list signatures of known fraudulent voting transactions to exemplars taken from suspects. • States generally require voters to apply for absentee ballots in writing. They also customarily require an absentee voter to sign an oath (generally on the ballot envelope) attesting to the authenticity of the vote. These signatures can be used to identify fraudulent voting transactions and might also help identify potential defendants. • Election officials are generally required to maintain logs of absentee applications received and approved, and of ballots issued, returned, and challenged. Once a few fraudulent voting transactions have been identified, this information can be used to identify the subjects with whom the voters involved dealt, and to locate other voters who also dealt with the same subjects. • Election day tally sheets normally contain the handwritten certification of the poll officials who prepared them, and in many states these officials are required to execute an oath attesting to the authenticity and accuracy of the returns. These documents may corroborate the identities of those persons with official access to the tally sheets. 89