Rodney Richardson, 44, of Atlanta, was arrested May 17 in DeKalb, Ga., by U.S. marshals, police said.
Nassau County detectives from the fugitive section, the sex offender registry act section, U.S. marshals and Freeport police were working on a joint investigation in March and discovered that Richardson was no longer living at his Freeport address, a police spokeswoman said Monday.
According to the New York State Department of Criminal Justice Services, Richardson was convicted in 1994 of first-degree sexual assault and served nearly 4 years at the Clinton Correctional Facility in Dannemora.
Richardson is being held in the Nassau County jail for a Monday court appearance. He is represented by Legal Aid.