did not provide a comment for the story. >> so wait. is the spokesperson for rosenstein denying an investigation was opened up? >> reporter: this -- the spokesperson for mccabe is not offering any comment for this story. if you look at the comment from a source in the justice department, this source only said that rosenstein never said that he wanted to rein in the president. he was just discussing ways in which to conduct the investigation. >> why would rosenstein okay opening a probe when it was his own memo that the white ouse was using to justify firing comey in the first place? >> reporter: that's a good question, and it's a bit puzzling. for the deputy attorney general, this obstruction investigation into trump and the appointment of the special counsel certainly turned his entire justice department tenure into the awkward role of supervising the mueller investigation after he wrote the memo justifying comey's firing, that sources say