Was there an assassin on Grant's train?

[Pamela]

Laurie, do you have an explanation for how Father Menus (I can't find apostrophies on my Droid tablet!) letter came into Booth's possession? John was in Richmond so who else in the house would have taken it? Weichmann didn't give to Booth. Soon after the failed kidnapping or whatever it was, Booth telegraphed Weichmann with a message for John. Weichmann had just witnessed very suspicious and disturbing events, wrote to Father Menu and confided in Gleason. Why else would Booth telegraph Weichmann? Why did John take Weichmann to the Herndon house?