Why some Chester County third-party voters were forced to use provisional ballots on Election Day

Election Day: Philly DA's race, Pennsylvania Supreme Court retention vote

The local focus in Philadelphia on Election Day will be on the District Attorney's race between incumbent Larry Krasner and former city judge Pat Dugan. Voters in the Keystone State will also decide if three Pennsylvania Supreme Court Justices will maintain their seats.

PHILADELPHIA - Registered third-party voters in Chester County were forced to use provisional ballots after election officials say some names did not appear in poll books.

What we know:

Chester County Voter Services says an issue with the poll books at all precincts was reported just after polls opened in Pennsylvania at 7 a.m. 

Election officials said the erroneous poll books did not include the names of registered third-party voters. 

Supplemental poll books were sent to precincts across Chester County. 

The issue caused some third party voters to vote by using a provisional ballot.

County officials say supplemental poll books were sent to all 230 of the county's polling locations by 3:45 p.m. Tuesday, and that all registered voters who voted in person were able to cast their ballots. 

Chester County Voting officials say polls will close at 10:00 p.m. due to the issue. 

By the numbers:

Election officials say there are over 385,000 registered voters in Chester County, and more than 75,000 are third-party voters.

Third-party includes independents, libertarians, and those registered as ‘No Affiliation’ or ‘Non-Partisan.’

What they're saying:

Chester County Voter Services says it will conduct an investigation to "determine how third-party registered voters were omitted from the poll books."