Federal agents raided the laboratory and home of an Illinois chemist who authorities believe created one of the steroids at the heart of the BALCO sports doping scandal, the San Francisco Chronicle reported Friday. Investigators with the Internal Revenue Service's criminal investigation division and the U.S. Food and Drug Administration searched Thursday in Champaign, Ill., at the home and laboratory of chemist Patrick Arnold, the newspaper reported, citing sources who wished not to be identified. BALCO founder Victor Conte and vice president James Valente identified Arnold as the source of a once-undetectable steroid called "the clear." Conte, Valente, track coach Remi Korchemny and Greg Anderson _ the longtime friend and personal trainer of Giants slugger Barry Bonds _ pleaded guilty to distributing steroids to elite athletes and will be sentenced next month.