One of the main lines of argument cited by the seven former CIA directors in urging President Obama to reverse his attorney general's decision to review CIA interrogations is that career lawyers at the Department of Justice had already reviewed those same files.
Career prosecutors under the supervision of the US Attorney for the Eastern District of Virginia determined that one prosecution (of a CIA contractor) was warranted. A conviction was later obtained. They determined that prosecutions were not warranted in the other cases.
Attorney General Holder's decision to re-open the criminal investigation creates an atmosphere of continuous jeopardy for those whose cases the Department of Justice had previously declined to prosecute
If criminal investigations closed by career prosecutors during one administration can so easily be reopened at the direction of political appointees in the next, declinations of prosecution will be rendered meaningless
But the Justice Department's response to these claims contains a buried piece of information: "Given the recommendation from the Office of Professional Responsibility as well as other available information, he believed the appropriate course of action was to ask John Durham to conduct a preliminary review..."
For the uninitiated, this means that the preliminary report sent to Holder by the Office of Professional Responsibility on the torture-related lawyering of the Bush-era DOJ political appointees -- a report prepared by career prosecutors -- recommended that the cases deemed closed during the Bush administration be re-examined.
Holder is following the advice of his in-house 'internal affairs' shop... and didn't simply make the decision after reviewing the files himself.