Verification of illegal immigrants is scrutinized amid healthcare debate Los Angeles County health worker Leonardo Rincon lifts the birth certificate up to the light and expertly scrutinizes it. Do faint watermarks show up? Yes. He rubs his thumb over the official seal to see if it is raised. It is. He checks the number of digits in the document number. Perfect. Ruth Torres, he decides, has brought in valid U.S. birth certificates for her six children, a valid U.S. passport for her husband and a valid green card for herself, a legal immigrant from Mexico. The family will continue to receive public healthcare benefits, as least for the next year. Since July 2008, when Los Angeles County began implementing tougher federal verification rules, Rincon and his colleagues have gone back to check the documents of more than 100,000 recipients of Medi-Cal, the public healthcare program for low-income residents.