Federal investigators served a search warrant at the offices of Paradise Valley Community College, a campus of Arizona’s Maricopa County Community College District, as part of an investigation into alleged fraud involving more than $4-million in federal funds. The inquiry involves an AmeriCorps program, known as Project Ayuda, that pays students for doing community service. Investigators are examining whether the college paid students for work they didn’t perform or mishandled the money in other ways. A spokesman for the district said the college’s director of service learning had recently resigned. The college’s president placed that employee on leave after he saw her tampering with subpoenaed files, according to court documents.