The letters had become annual annoyances, Mary Lou Wingbermuehle says now, recalling the vexing, impersonal missives that arrived each year from the Internal Revenue Service.
The Missouri resident was informed tersely that she had under-reported thousands of dollars of personal income earned from fast-food eateries and other employers in the San Diego area.
"I've never even been to California," says Wingbermuehle, a 42-year-old mother of two who lives in Arnold, Mo., a suburb of St. Louis.
Knowing that something was amiss, Wingbermuehle embarked on an intensive letter-writing campaign of her own, contacting officials at the IRS, the Social Security Administration, supposed employers, and, finally, the U.S. Immigration and Naturalization Service.
On Monday, U.S. immigration officials declared that Wingbermuehle had been victimized by an "impostor," a woman who had assumed her identity, apparently after having somehow obtained her birth certificate and her Social Security number.
The impostor, an undocumented immigrant from Mexico, has been using Wingbermuehle's identity since at least 1973, authorities say.
Federal agents working the alleged scam arrived at the Pollo Loco restaurant in National City on Friday and arrested a suspect, who officials say has declined to give her name in court but who was identified by U.S. authorities as Octavia Tirado Beltran, 41.
She was charged in a federal complaint with falsely attesting that she was U.S. citizen on a federal form and using someone else's Social Security number.
"I felt like I had been cloned," Wingbermuehle, 42, said after hearing of the arrest. "Nobody believes me when I tell them this story."
U.S. Magistrate Roger C. McKee in San Diego ordered Monday that the suspect, listed in records officially as Jane Doe, be held in lieu of $100,000 bond.
Still unclear, officials say, is how the alleged impostor, a resident of San Diego, obtained the documentation of a Missouri native. Wingbermuehle speculates that she may have lost her birth certificate years ago, but she isn't sure.
For a time, officials say, the impostor used the name Mary Lou Slavitt, Wingbermuehle's maiden name. After successive marriages, officials allege, she used the surnames of Curcio, and, then, Galanius.
Immigration agents say impostor scams are common; some victims may never know that their identities have been purloined.
"There's a lot of impostor cases out there," said Warren Long, a special immigration service agent, who noted the existence of an active black market in stolen, lost and illegally sold identification documents, bearing the names of both the living and the dead. Counterfeit documents also abound in the immigration underworld.
The sales reflect the difficult plight of undocumented immigrants, who are often desperate for any means to allow them to remain on U.S. soil.
But, with increasing computer scrutiny of employment and other records, authorities say it may be more difficult for impostors to go undetected for long periods.
In this instance, however, it was largely the perseverance of Wingbermuehle that broke the case.
She says others had advised her to apply for a new Social Security number, but she feared that the previous records might still cause her trouble, particularly if her "double" had defaulted on a payment or committed a crime.
"I wanted to get this all taken care of," said Wingbermuehle, who works for the Missouri state government. "I didn't want to mess with the IRS any more. . . . I didn't want my credit rating ruined."
Fortunately, the woman who allegedly used Wingbermuehle's identity was, from all available accounts, an upstanding resident who paid her bills. She possessed 22 credit cards, including American Express and Visa gold cards, said Rudy Murillo, an immigration service spokesman.
"She had every form of credit I've ever seen," said Long, the immigration agent who worked on the case.
Said Wingbermuehle, "I'm very lucky she was a model citizen."
A co-worker described the suspect as a dedicated employee who had risen from the ranks since her initial employment four years ago to become general manager of the Pollo Loco restaurant in National City. "We never imagined something like this would happen," said the colleague, who declined to be identified by name. "She's a very nice person and was always a very hard worker."
The Missouri woman was happily unaware of the problem until 1985, when the IRS first informed her that she had failed to report income--about $8,000--earned in the San Diego area. Similar letters followed in subsequent years, Wingbermuehle said.
On each occasion, Wingbermuehle says, she wrote back to the IRS, explaining that she had never worked in California; she included letters from her current employer and others. Tax officials apparently believed her, she said, because she was never required to pay the back assessments.
Wingbermuehle reached the conclusion that she and the other woman had mistakenly been issued the same Social Security number, a rarity.