City Controller Alan Butkovitz said Tuesday that he would audit the city's election process, hoping to find out why the names of long-registered voters did not appear in poll books, forcing them to use provisional paper ballots on Election Day.

The three city commissioners, in charge of running Philadelphia's elections, have already announced their own plans to figure out what went wrong with the poll books, part of a full-scale review of the general election. Mayor Nutter said his staff also would review the commissioners' operations.

Commissioners Al Schmidt, Stephanie Singer, and Anthony Clark said they welcomed Butkovitz's attention.

Schmidt reported last week that about 27,100 people voted by provisional ballot Nov. 6, more than double the number who did so in the 2008 presidential election. Provisional ballots are sealed in separate envelopes and held aside, to be counted later if election officials can verify the voter's registration. - Bob Warner