Another issue stemmed from a problem extracting voter data from the state database, leaving some voters excluded from the books.
"If there is an issue with our extraction of the information from the [state] database, we sure as heck better figure out what that issue is, because otherwise who's to say next time it's not a bigger problem," City Commissioner Al Schmidt said Wednesday.
Poll books are printed by a private firm with data from a state-maintained database of registered voters. Ronald Ruman, spokesman for the Pennsylvania Department of State, said that the system that has been in place for years seems to have worked.
"We still don't know what happened," said Ellen Kaplan, vice president of the Committee of Seventy, adding that there was a backlog of registrations to process before Election Day. "What will the city do to make sure this doesn't happen in future city elections?"
Gregory Irving, the acting voting registration administrator, said that the investigation is ongoing. Mayor Nutter said that his office will conduct a review, and City Controller Alan Butkovitz has begun an investigation.
These issues were complicated by the fact that many voters cast their ballots infrequently, usually only during presidential elections. Since 2008, however, 650 of the city's 1,687 voting divisions have moved. Two-thirds of voters listed in polling materials went to the wrong site, the report said. In other cases, poll workers did not look for or could not find voters' names.
Irving said that half the poll workers - about 4,000 - did not attend training. Schmidt said that, by law, City Commissioners can't require them to.
The report listed several recommendations, including: ensuring that new voters who've recently turned 18 are added to polling material; revamping Election Board training to ensure that workers know how to find voters' names in the books; and working with the state to ensure that all information is accurately extracted.
On Twitter: @Jan_Ransom