<p>WASHINGTON -- President Clinton's national security adviser is the subject of a criminal investigation after he removed from a secure reading room at the National Archives classified documents related to the 9/11 investigation, federal officials said. A lawyer for Samuel Berger said last night that on two occasions, while reviewing hundreds of documents in preparation for the 9/11 Commission's investigation, his client inadvertently removed several copies of an after-action report assessing the effectiveness of the Clinton administration's counterterrorism efforts during the run up to the 2000 millennium celebrations. Lanny Breuer, Mr. Berger's lawyer, also said that Mr. Berger had intentionally removed handwritten notes that he had taken during three separate visits to the Archives last fall to review classified documents. Mr. Breuer said removing those notes was a violation of National Archives policy, and that Mr. Berger regretted the action. "He knew it was a technical violation, and he admits that it was an error in judgment." In a statement last night Mr. Berger said, "I deeply regret the sloppiness involved, but had no intention of withholding documents from the commission and, to the contrary, to my knowledge every document requested by the commission from the Clinton administration was produced." A Justice Department official last night said that the after-action report was highly critical of the millennium efforts and said that luck played a major role in preventing several terrorism attacks in the U.S. in 1999, including the arrest of would-be bomber Ahmed Ressam as he tried to enter the U.S. from Canada. That report went on to say there were glaring weaknesses in the efforts, and the actions taken shouldn't be used as an operating model for the government, the official said......"</p>