Charges against a cashier accused of stealing thousands of dollars from a Metro parking garage have been dropped because transit officials miscalculated revenue and ultimately concluded that he stole no money.

Metro officials had accused Daniel Mulugeta of stealing more than $2,000 from a parking facility in Wheaton, basing the charge on the difference between the number of cars that passed through his lane each day and the amount of money he turned in. But officials failed to factor in revenue from electronic SmarTrip cards, which a large majority of customers use.

"After a reanalysis, we determined the variance was negligible," said spokeswoman Lisa Farbstein. "Apparently when the investigation began, we told [the state's attorney] that a certain amount of money was stolen. As the investigation progressed, we were unable to document all the money."

John McLane, a spokesman for the Montgomery County state's attorney's office, said charges were dropped because "the evidence we had was insufficient -- one, not only to prove Daniel Mulugeta was guilty, but, two, for us ethically to bring it to trial."

Mulugeta was one of two Metro cashiers charged with felonies for allegedly stealing money at parking facilities. The charges were part of a probe that found that as much as $1 million a year had been taken for an indeterminable number of years from the transit agency. Metro officials have said that patrol officers observed the cashiers taking money. Thirty-three cashiers have been fired as a result of the investigation.

Metro managers blamed the firm that operates its 52 parking facilities, Penn Parking Inc., and ended a 10-year partnership in May. Penn's last day will be June 26, when another firm will take over.

Penn executives and union officials representing the cashiers have maintained that they were scapegoats for the agency's mismanagement. Penn officials said they warned Metro officials in 2000 that money was being stolen and recommended several improvements, including switching to tokens instead of cash or installing equipment that is more secure.

"I think it just proves what Penn Parking has been saying all along," said Lisa Renshaw, president of Penn. "Operations at [Metro] are sloppy."

Renshaw said Mulugeta would be rehired "as soon as I find a position for him."

Union leaders have challenged 16 of the firings; the other 15 workers were on probation, and their dismissals cannot be challenged. Emil Abate, secretary-treasurer of Local 27 of the Parking and Service Workers Union, said "the dismissal of the criminal charges against Daniel Mulugeta calls into question the [other] cashier removals."

Farbstein said that the case is proceeding against the second cashier and that officials were "very confident of theft" in that one because "that case includes surveillance."

T. Dana Kaufmann, Fairfax County's representative on the Metro board, said that it was difficult to prove theft at parking lots because people pay in different ways. "What we have unfortunately realized is that people come in and out . . . and getting an exact number for a time frame isn't easy," he said. "If we missed one variable, I'm disappointed but not terribly surprised."

Gary Segal, Mulugeta's attorney, said Metro officials "had all the evidence to know that Daniel hadn't done anything wrong. Either they were too lazy or they were trying to cover up their own ineptitude by blaming the low man on the totem pole and blaming these guys who work for Penn Parking who they thought would just roll over and go away. "

Abate said Mulugeta, who worked for Penn for nine years and is also a student at the University of Maryland, has been unemployed since he was fired in December.

Abate called on Metro to pay about $7,000 in missed wages and to require the new parking company to hire Penn employees.

Mulugeta declined requests to be interviewed but said in a statement that "I have never stolen anything from my employer" and that "this whole affair has been extremely upsetting. It has taken a great emotional toll on me."