Rep. Rush Holt said circumstantial evidence was not enough and asked FBI director Robert S. Mueller to appear before Congress to provide an account of the investigation .
Rep. Rush Holt represented the district where the anthrax letters were mailed .
Rep. Rush Holt , who represented the district where the anthrax letters were mailed , said circumstantial evidence was not enough and asked FBI director Robert S. Mueller to appear before Congress to provide an account of the investigation .