Hillary Clinton's chief of staff, Margaret Williams, and her confidante, Susan Thomases, on Thursday told the Senate committee investigating Whitewater that they knew of no plan by the First Lady to keep police away from Vincent Foster's papers. But chairman Alfonse D'Amato and other Republican senators dismissed as "not credible" testimony that they were merely "reaching out" to grieving friends in more than a dozen phone calls with the First Lady and White House aides shortly after they searched Foster's office. "D'Amato is trying to prove a conspiracy that will be very difficult to prove," Martin L. Gross, author of The Great Whitewater Fiasco: An American Tale of Money, Power and Politics, told TIME Daily. "It seems clear that there was a series of phone calls between Williams, Thomases and White House counsel Bernard Nussbaum the morning after Foster's death. And it's also clear that the Whitewater papers were moved by Williams to Mrs. Clinton's bedroom closet right after these phone calls. The interesting question is, why would the White House want to hide the papers?