On 28 March 2006, David Rivkin pleaded guilty to charges of conspiracy and tax evasion in U.S. District Court in Manhattan. "I knew that the losses should not have been claimed on the tax forms," Rivkin told Judge Kaplan. Rivkin admitted that he conspired with others between January 1999 and May 2004 to prepare and execute false documents so that clients could file false tax returns. He also admitted that he took steps to conceal the existence of fraudulent tax shelters from the Internal Revenue Service and avoided registering the shelters with the IRS by claiming attorney-client privileges. Rivkin signed an agreement to cooperate with prosecutors, who could then ask the judge to consider giving Rivkin a more lenient sentence rather than the years he might face in prison. Sentencing was set for Feb. 9, 2007.