A second top official is out at the Internal Revenue Service, as the agency reels from a scandal over revelations that it gave special scrutiny to conservative groups applying for tax exemption. An internal memo said that Joseph Grant, commissioner of the IRS's tax-exempt and government entities division, will retire on June 3. That news came after President Barack Obama appointed a new acting IRS commissioner earlier Thursday, hours after he said he knew nothing about the actions within the agency until they were reported in the press. He named Daniel Werfel to fill the position vacated by Steven Miller, who resigned Wednesday on the Treasury's request. The president, however, declined to endorse appointing an independent counsel to investigate the controversy.