Double voting in the District and Maryland has persisted despite a 1998 effort to crack down on the practice, according to election records, and local officials say that an election reform law signed this week by President Bush will not fully address the problem.

Records indicate that two dozen voters cast ballots in both the District and Maryland in the Sept. 10 primary and that 90 voters did so in the November 2000 election. Double voting in the District and Virginia appears to be far less common -- the records show only six people voting in both the District and Northern Virginia in November 2000.

A provision in the new federal law requires states to create centralized, computerized voter rolls to prevent multiple voting by people registered in more than one place. The District and Maryland already have such records, however. The problem is that different jurisdictions seldom compare registration lists or voting records to spot duplicate names, Washington area elections officials said.

The last time such a review was done was in 1998, when D.C. elections officials looked at voting records and gave the U.S. attorney's office the names of 261 people who appeared to have double-voted in the District and Prince George's County during the previous three years.

But that investigation did not lead to any prosecutions, said Channing Phillips, a spokesman for the U.S. attorney in the District. Phillips said yesterday that officials could not find the paperwork explaining why no one was prosecuted, and Alice P. Miller, executive director of the D.C. Board of Elections and Ethics, said her office could not locate those records either.

Miller said the District has not made a more recent attempt to find double-voters, in part because the city's drive to obtain and install new voting equipment was a higher priority.

A review by The Washington Post found that more than 10,000 people are registered to vote in both the District and either Prince George's or Montgomery counties. The Post found people listed as having cast ballots in the District and Maryland on the same day by studying voter histories that were based on signatures collected when voters checked in at the polls.

When contacted by a reporter, the voters said that they had cast a ballot only once and that the records must be wrong.

"That must be a mistake," said Denise Daniels, 33, listed as voting in both Prince George's and the District in 2000 and 2002. "I'm going. I have to go. I don't know what this is about."

Harold Bobbitt Jr. also is listed as a double-voter.

"I moved to College Park," he said. "I'm no longer a District voter. I started voting in College Park in 2000, but I didn't vote in D.C. That might be a mistake in the D.C. computer."

Bobbitt noted that he has the same name as his father, Harold Nathaniel Bobbitt Sr. The voting records, however, indicate that ballots were cast in the District and Maryland in 2000 and 2002 by Harold Nathaniel Bobbitt Jr., age 46. And Bobbitt and his father are listed as having voted in last month's D.C. primary.

The most prolific repeat voter, according to the records, is Betty J. Johns, 69, listed as casting ballots in both Maryland and the District in the 1996 and 2000 presidential elections, as well as in the Democratic primaries in the District and Prince George's on Sept. 10. A woman who answered the phone at her residence said no one there would talk to a reporter.

Larry Poteat Jr., 22, moved to Prince George's County this year from the District but was listed as voting in both places in September. His father, Larry Poteat Sr., said that he voted in the primary in the District, yet there is no record of the father's vote.

"If they don't have me down as voting, something's crazy," the father said. "They gave both of the votes to [my son], in Prince George's and D.C."

Election officials said it is possible for precinct workers to make mistakes when recording who voted. Such errors also would be a serious problem, voting reform activists say, because they could make it impossible to compare the number of ballots counted with the number of people listed as voting. Matching those two figures is a first step in making sure that ballots were not discarded and that phony ballots were not counted.

In the District, vote fraud is a felony punishable by five years in prison or a $10,000 fine. In Maryland, the punishment is a fine of up to $2,500 and up to five years in prison.

When registering to vote, people are asked on a form where they were previously registered, but some don't fill it out. The form is then sent directly to the previous jurisdiction if it is in the same state. But if it is not in the same state, the form goes to the capital of the state where they used to live, which slows down the process, election officials said.

Officials said the best way to weed out such names is to compare lists of all registered voters, which the District initiated in 1998. Election supervisors in Prince George's and Montgomery said it would be up to the state to launch such an effort.

Reform advocates said cleansing registration lists of old names and maintaining accurate voting records are crucial steps in ensuring clean elections.