Investigators have uncovered a massive scheme to defraud taxpayer-funded healthcare programs of millions of dollars by recruiting homeless patients for unnecessary medical services in California. The enterprise churned thousands of indigents through hospitals over the last four years and billed Medicare and Medi-Cal for costly and unjustified medical procedures, federal, state, and local investigators said. After raids on three hospitals in Los Angeles and Orange counties, one hospital chief executive faces criminal charges and executives at two other facilities were accused of fraudulent business practices in a related civil lawsuit filed by Los Angeles City Atty. Rocky Delgadillo.