Given the unfathomable magnitude of the ongoing BP oil spill in the Gulf of Mexico, the announcement of a federal criminal investigation didn’t come as a particular surprise. As one solution after another failed and the intensity of the catastrophe mounted, the crisis became political as well as environmental–with action from the Justice Department all but inevitable.

“We must … ensure that anyone found responsible for this spill is held accountable,” announced Attorney General Eric Holder in June. “That means enforcing the appropriate civil–and if warranted, criminal–authorities to the full extent of the law.”