His United States National Security Advisor John Poindexter was charged with multiple felonies and later resigned. Reagan later nominated former Ambassador Frank Carlucci to replace Poindexter. His Secretary of Defense Caspar Weinberger was thought to be guilty, but resigned before a trial could begin. Reagan later nominated Carlucci to serve as Defense Secretary for the rest of his term. Oliver North, a member of the United States National Security Council, resigned and was indicted for his involvement in the affair. In February 1987, White House Chief of Staff Donald Regan also resigned because of an ongoing feud between Regan and First Lady Reagan about his handling of the affair.