It might not have been confirmed until after the event. Or like the Godfather, Trump might have been keeping his enemies close. Remember VP Johnson was riding in the car right behind JFK when JFK was shot via triangulated fire.  There are photos and videos clearly showing Johnson DUCKING down in his seat, because he KNEW this was the location for the assassination.....his mistress confirmed that LBJ knew about the assassination the night before it happened. So the closeness of the VP to the POTUS when the POTUS gets assassinated, is just to TRY to provide plausible deniability of their direct involvement in the assassination plot.