The U.S. attorney’s office is looking further into the outbreak of last year’s listeria epidemic.   Attorney for the listeria victims, Bill Marler, says that investigators  have approached him and asked for the case files.   A spokesperson for the U.S. attorney’s office has declined to comment and would not confirm that or whether or not it was being considered a criminal or civil case.  According to the Center for Disease Control and Prevention 30 people died and 146 fell ill during the listeria outbreak which was traced back to a farm in southeastern Colorado.