In the hectic eight days after President Donald Trump fired FBI Director James Comey, Deputy Attorney General Rod Rosenstein and top FBI officials viewed Trump as a leader who needed to be reined in, according to two sources describing the sentiment at the time.

They discussed a range of options, including the idea of Rosenstein wearing a wire while speaking with Trump, which Rosenstein later denied. Ultimately, then-acting FBI Director Andrew McCabe took the extraordinary step of opening an obstruction of justice investigation even before special counsel Robert Mueller was appointed, the sources said. The obstruction probe was an idea the FBI had previously considered, but it didn’t start until after Comey was fired. The justification went beyond Trump’s firing of Comey, according to the sources, and also included the President’s conversation with Comey in the Oval Office asking him to drop the investigation into his former national security adviser Michael Flynn.