 Martin was previously in private practice at the law firm of Armstrong Teasdale concentrating in the areas of white collar defense and corporate compliance.Attorney General John Ashcroft appointed Martin as U.S. Attorney to replace Raymond Gruender when President George W. Bush appointed him to the Eighth Circuit Court of Appeals in mid-2004.During Martin's tenure, his office settled a high-profile case against Gambro Healthcare alleging that the company had paid doctors kickbacks to get patient referrals in a scheme to defraud Medicare; the company settled for $350 million, one of the largest settlements in Justice Department history.