there was a fourth bullet in snipers nest

[Donald Diabo]

"The presence of the cartridge in the chamber did not necessarily mean that the assassin considered firing another bullet, since he may have reloaded merely by reflex.51

Apart from the cartridge in the rifle, three expended cartridge cases were found in the southeast portion of the sixth floor of the Texas School Book Depository Building, lying between the south "

http://www.archives.gov/research/jfk/warre...10.html#bullets