MIAMI, July 27 - Almost all the electronic records from the first widespread use of touch-screen voting in Miami-Dade County have been lost, stoking concerns that the machines are unreliable as the presidential election draws near.
The records disappeared after two computer system crashes last year, county elections officials said, leaving no audit trail for the 2002 gubernatorial primary. A citizens group uncovered the loss this month after requesting all audit data from that election.
A county official said a new backup system would prevent electronic voting data from being lost in the future. But members of the citizens group, the Miami-Dade Election Reform Coalition, said the malfunction underscored the vulnerability of electronic voting records and wiped out data that might have shed light on what problems, if any, still existed with touch-screen machines here. The group supplied the results of its request to The New York Times.
"This shows that unless we do something now - or it may very well be too late - Florida is headed toward being the next Florida," said Lida Rodriguez-Taseff, a lawyer who is the chairwoman of the coalition.
After the disputed 2000 presidential election eroded confidence in voting machines nationwide, and in South Florida in particular, the state moved quickly to adopt new technology, and in many places touch-screen machines. Voters in 15 Florida counties - covering more than half the state's electorate - will use the machines in November, but reports of mishaps and lost votes in smaller elections over the last two years have cast doubt on their reliability.
Like "black boxes" on airplanes, the electronic voting records on touch-screen machines list everything that happens from boot-up to shutdown, documenting in an "event log" when every ballot was cast. The records also include "vote image reports" that show for whom each ballot was cast. Elections officials have said that using this data for recounts is unnecessary because touch-screen machines do not allow human error. But several studies have suggested the machines themselves might err - for instance, by failing to record some votes.
After the 2002 primary, between Democratic candidates Janet Reno and Bill McBride, the American Civil Liberties Union of Florida conducted a study that found that 8 percent of votes, or 1,544, were lost on touch-screen machines in 31 precincts in Miami-Dade County. The group considered that rate of what it called "lost votes" unusually high.
Voting problems plagued Miami-Dade and Broward Counties on that day, when touch-screen machines took much longer than expected to boot up, dozens of polling places opened late and poorly trained poll workers turned on and shut down the machines incorrectly. A final vote tally - which narrowed the margin first reported between the two candidates by more than 3,000 votes - was delayed for a week.
Ms. Reno, who ultimately lost to Mr. McBride by just 4,794 votes statewide, considered requesting a recount at the time but decided against it. Seth Kaplan, a spokesman for the Miami-Dade elections division, said on Tuesday that the office had put in place a daily backup procedure so that computer crashes would not wipe out audit records in the future.
The news of the lost data comes two months after Miami-Dade elections officials acknowledged a malfunction in the audit logs of touch-screen machines. The elections office first noticed the problem in spring 2003, but did not publicly discuss it until this past May.
The company that makes Miami-Dade's machines, Election Systems and Software of Omaha, Neb., has provided corrective software to all nine Florida counties that use its machines. One flaw occurred when the machines' batteries ran low and an error in the program that reported the problem caused corruption in the machine's event log, said Douglas W. Jones, a computer science professor at the University of Iowa whom Miami-Dade County hired to help solve the problem.
In a second flaw, the county's election system software was misreading the serial numbers of the voting machines whose batteries had run low, he said.
The flaws would not have affected vote counts, he said - only the backup data used for audits after an election. And because a new state rule prohibits manual recounts in counties that use touch-screen voting machines except in the event of a natural disaster, there would likely be no use for the data anyway.
State officials have said that they created the rule because under state law, the only reason for a manual recount is to determine "voter intent" in close races when, for example, a voter appears to choose two presidential candidates or none.
Touch-screen machines, officials say, are programmed not to record two votes, and if no vote is recorded, they say, it means the voter did not cast one.
But The Sun-Sentinel of Fort Lauderdale, in a recent analysis of the March presidential primary, reported that voters in counties using touch-screen machines were six times as likely to record no vote as were voters in counties using optical-scan machines, which read markings on paper ballots.
The A.C.L.U. of Florida and several other voting rights groups have sued to overturn the recount rule, saying it creates unequal treatment of voters. Counties that use optical-scan machines can conduct recounts, though only in extremely close races.
Mr. Kaplan says that the system crashes had erased data from other elections besides Ms. Reno's, the most recent being municipal elections in November 2003. Under Florida law, ballot records from elections for state and local office need be kept for only a year. For federal races, the records must be kept for 22 months after an election is certified. It was not immediately clear what the consequences might be of breaching that law.
Mr. Kaplan said the backup system was added last December.
An August 2002 report from Miami-Dade County auditors to David Leahy, then the county elections supervisor, recommended that all data from touch-screen machines be backed up on CD's or elsewhere. Professor Jones said it was an obvious practice long considered essential in the corporate world.
"Any naïve observer who knows about computer system management and who knows there is a requirement that all the records be stored for a period of months," Professor Jones said, "would say you should obviously do that with computerized voting systems."
Buddy Johnson, the elections supervisor in Hillsborough County, which is one of the state's largest counties and which also uses touch-screen machines, said his office still had its data from the 2002 elections on separate hard drives.
Mr. Kaplan of the Miami-Dade elections office could not immediately explain on Tuesday afternoon the system crashes in 2003. Martha Mahoney, a University of Miami law professor and member of the election reform group, said she requested the 2002 audit data because she had never heard an explanation of the supposedly lost votes that the A.C.L.U. documented after the Reno-McBride election.
"People can never be sure their vote was recorded the way it was cast, but these are the best records we've got," she said. "And now they're not there."