Is Attorney General Impeding Justice?

Writing in Op-Ed News, Jason Leopold claims US Attorney General Alberto Gonzalez may be obstructing justice by withholding emails from the the special prosecutor looking into the Plame Affair.

Sources close to the investigation into the leak of covert CIA agent Valerie Plame Wilson have revealed this week that Attorney General Alberto Gonzales has not turned over emails to the special prosecutor's office that may incriminate Vice President Dick Cheney, his aides, and other White House officials who allegedly played an active role in unmasking Plame Wilson's identity to reporters.

Moreover, these sources said that, in early 2004, Cheney was interviewed by federal prosecutors investigating the Plame Wilson leak and testified that neither he nor any of his senior aides were involved in unmasking her undercover CIA status to reporters and that no one in the vice president's office had attempted to discredit her husband, a vocal critic of the administration's pre-war Iraq intelligence. Cheney did not testify under oath or under penalty of perjury when he was interviewed by federal prosecutors.

Would anyone find that surprising if it's true?