TALLAHASSEE — Florida Gov. Rick Scott's administration violated federal law by trying to remove noncitizens from the voter rolls too close to the 2012 presidential election, a federal appeals court ruled Tuesday in calling the mistake-prone effort "far from perfect."

The decision by a three-judge panel of the 11th U.S. Circuit Court of Appeals in Atlanta invalidated efforts by the Department of State to identify and remove noncitizens from the voter rolls in advance of an election in which a Florida victory was crucial to President Barack Obama's re-election.

Federal law prohibits states from "systematic" removals of voters less than 90 days before a federal primary or general election.

Judges said they ruled in a case that might otherwise be moot to prevent Scott's administration from undertaking a future purge effort.

"This is a big win for Florida voters and a significant victory for good election administration practices," said Deirdre Macnab, president of the League of Women Voters of Florida, which joined the case on the plaintiffs' side. "Systematic computer purges are often wrong so they shouldn't come just before an election, when the voter can't get it corrected. … This is a precedent-setting case that upholds a key protection for voters."

The 2-1 decision was written by Judge Beverly Martin and joined by Judge Adalberto Jordan, who was born in Cuba and is a University of Miami law school graduate and a former assistant U.S. attorney in Miami. Judge Richard Suhrheinrich dissented.

Scott's chief elections official, Secretary of State Ken Detzner, issued a terse five-word statement through a spokeswoman: "We are reviewing the decision."

The state could ask for a rehearing before the full 11th U.S. Circuit Court of Appeals.

Last week, Detzner abandoned efforts to scrub the voter rolls of noncitizens in advance of the 2014 election in the face of overwhelming opposition from elected supervisors of elections. He had labeled the program "Project Integrity."

The state won a lower-court ruling in U.S. District Court in the case of Arcia vs. Detzner, but the plaintiffs appealed.

Elections supervisors and voter advocacy groups were alarmed in June 2012 when Scott's administration launched an effort to purge the voter rolls of noncitizens in advance of the statewide August primary election by comparing the rolls with other state and federal databases.

The 2012 list of about 180,000 suspect voters was based on driver's license data. The state soon whittled it to 2,600 and then to 198. Ultimately, about 85 voters were removed from the rolls.

Other groups challenging the purge included the Florida Immigrant Coalition, National Congress for Puerto Rican Rights and the Service Employees International Union. SEIU's testimony that it had to divert resources from voter registration to fighting the purge was "a concrete and demonstrable injury," the judges wrote.

The two named plaintiffs in the case are from Miami-Dade, and both were shocked to discover their names on a purge list: Karla Vanessa Arcia, a naturalized citizen from Nicaragua, and Melande Antoine, a naturalized citizen from Haiti.

The judges concluded that both women had legal standing "because they were directly injured by it when they were wrongly identified as noncitizens."

Attorneys for Detzner had argued that the women had no standing because they were ultimately not prevented from voting, but the judges said otherwise: "There was a realistic probability that they would be misidentified due to unintentional mistakes in the Secretary's data-matching process."

Scott has consistently defended the purge efforts as a way to reduce voter fraud. The state has spent more than $90,000 in legal fees in the case.

Steve Bousquet can be reached at bousquet@tampabay.com or (850) 224-7263.

Correction: The Florida Division of Elections spent $92,500 in legal fees in a lawsuit that ended Tuesday. An earlier version of this story gave an incorrect figure.