[JURIST] I. Lewis "Scooter" Libby [NYT profile] pleaded not guilty Thursday morning in federal court to charges of obstructing justice, perjury and making false statements. The former chief of staff for Vice President Dick Cheney was indicted [JURIST report] last week in the ongoing CIA leak investigation [JURIST news archive]. Libby's defense lawyer has suggested that Libby will rely on a poor memory defense and that Libby's inconsistent "recollections" to the grand jury and FBI investigators were the result of his hectic schedule and the near impossibility of recalling the details of conversations had years earlier. Libby reportedly testified before a grand jury that he learned the identity of covert CIA operative Valerie Plame from reporters, though evidence indicates that he may have learned her identity from Cheney and others a month earlier. AP has more.