POLL TAPES are printed vote results produced by each voting machine. They typically look like a cash register tape. Usually two or more copies are produced, one of which is sealed in an envelope and sent to election headquarters, with the other posted at the polling site for public viewing. In addition to results for each race, poll tape headers may show red flags, indicating possible compromise of the election, such as: delayed or incorrect date or time; indicators that multiple memory cards exist, or multiple versions of memory cards. (“memory cards” contain vote counting instructions and electronic ballot counts.) Poll workers sign poll tapes, a chain of custody record indicating that the tape was not substituted later. Poll workers also fill in a form on which they write the number of voters, votes, voting machine serial numbers, and other information, which is signed as well. Poll tapes should match these forms and should match total election results as well.
When more than one voting machine is used in a polling place, sometimes each machine prints a poll tape but often, a master tape combining all machines is printed by networking them together. Mail-in and centrally counted votes tend to omit printing poll tapes, though it is best to have central count machines produce batch tapes, equivalent to poll tapes. Early votes, and votes at combined vote centers sometimes omit poll tapes, reducing accountability while explaining that the tapes would be too long.
Poll tapes can include reporting of blank ballots cast, undervotes and overvotes. Each voting machine can also print another kind of tape, an audit tape, which provides time-stamped information for events like turning the machine off and on, recalibrating it, and more.
Signed poll tapes are a crucial check and balance and a key chain of custody record, because voting machine counts are transferred to a central tabulator where votes can be altered. Private contractors sometimes publish election results instead of public election offices. Poll tapes can help deter election fraud during aggregation and reporting phases, if members of the public take pictures of them. In elections of questionable integrity, poll tapes go missing, or do not match reported results. Sometimes local officials instruct poll workers not to print poll tapes, or refuse to allow the public to see the printed tapes. Even when the law requires posting poll tapes, some election officials request permission to be excused from it. Some simply ignore the law. Sometimes officials destroy poll tapes in violation of records retention laws. Occasionally counterfeit poll tapes are produced. Sometimes, examining poll tapes shows that certain voting machines were omitted from results.
Poll tapes are not inviolable because they can be falsified by tampering with memory cards or voting machine firmware. However, the frequency of poll tape anomalies, obstruction, and violations indicates that public viewing and taking pictures of poll tapes may be a significant deterrent for election results fraud.