Booth's visit to the Surratt Boarding House after the assassination

[RJNorton]

(11-14-2012 06:05 PM)Laurie Verge Wrote:  He did time his deed with a line causing laughter from the audience to give him an advantage.

It seems for the better part of my life I have frequently read that Booth knew the play so well that he timed his shot to coincide with the greatest laughter in the play. He apparently knew this would come in the c. 10:00-10:30 P.M. time frame.

My question is - what is the original source that says Booth thought this way? Or is this similar to the "was Herold at Seward's?" question in which some early authors included this in their books and subsequent authors assumed it was fact and included it as such.

As far as I know this "timing of loudest laughter plan" of Booth's is not in his diary, not in any letter he wrote, not in any of the conspirators' statements, etc. Where does it originate? Was the timing of the shot really a pre-planned thing, or was it more of a random thing that took place when Booth was good and ready to do it?