In 1872, Grant signed into law an act that ended private moiety ("tax collection") contracts, but an attached rider allowed three more contracts. Boutwell's assistant secretary William A. Richardson, hired John B. Sanborn to go after "individuals and cooperations" who allegedly evaded taxes. Retained by Richardson (as Secretary), Sanborn aggressively collected $427,000 in supposed delinquent taxes, keeping half for himself, splitting $160,000 of his money with others. During an 1874 Congressional investigation, Richardson denied involvement, but Sanborn said he met with Richardson six times over the contracts. Congress severely condemned Richardson's permissive manner. Grant appointed Richardson judge of the Court of Claims, and replaced him with reformer Benjamin Bristow. In June, Grant and Congress abolished the moiety system.