Assassination Trivia

[RJNorton]

One Lincoln assassination author claimed that the White House stable fire of February 10, 1864, was actually an assassination attempt on Abraham Lincoln. The thinking was that the White House staff would race out to fight the flames and Lincoln, left deserted in the White House, could then be assassinated. The plan failed when Lincoln himself departed the White House to join the fight against the flames.

What author made this claim? (as far as I know there is only one)