of which were Western-Winchester and one of which was Remington-Peters; prior to the shooting the killer had an expended Remington-Peters cartridge case in his revolver, which was ejected with the three Western- Winchester and one Remington-Peters cases; and one of the Western-Winchester cases was not found. (3) The killer was using hand-loaded ammunition, that is, ammunition which is made with used cartridge cases to save money; thus he might have loaded one make of bullet into another make of cartridge case. 78 This third possibility is extremely unlikely, because when a cartridge is fired the cartridge case expands, and before it can be reused it must be resized. There was, however, no evidence that any of the four recovered cartridge cases had been resized. 79

The Struggle for the Revolver

Officer McDonald of the Dallas police, who arrested Oswald, stated that he had struggled with Oswald for possession of the revolver and that in the course of the struggle, "I heard the snap of the hammer, and the pistol crossed my left cheek * * * the primer of one round was dented on misfire at the time of the struggle. * * *" so However, none of the cartridges found in the revolver bore the impression of the revolver's firing pin. 81 In addition, the revolver is so constructed that, the firing pin cannot strike a cartridge unless the hammer (which bears the firing pin) has first been drawn all the way back by a complete trigger pull. 82 Had the hammer gone all the way back and then hit the cartridge, it is unlikely that the cartridge would have mis-fired. 83 It would be possible for a person to interject his finger between the hammer and the cartridge, but the spring driving the hammer is a very strong one and the impact of the firing pin into a finger would be clearly felt. 84 However, the cylinder and the trigger are interconnected and the trigger cannot be fully pulled back if the cylinder is grasped. 85 Therefore, if Oswald had pulled on the trigger while McDonald was firmly grasping the cylinder, the revolver would not have fired, and if the gun was grabbed away at the same time the trigger would have snapped back with an audible sound. 86

The Paraffin Test

During the course of the interrogation of Lee Harvey Oswald following the assassination a paraffin test was performed by the Dallas police on both of his hands and his right cheek. The paraffin cast of Oswald's hands reacted positively to the test. The cast of the right cheek showed no reaction. 87

To perform the paraffin test, layers of warm liquid paraffin, inter-leaved with layers of gauze for reinforcement, are brushed or poured on the suspect's skin. The warm sticky paraffin opens the skin's pores and picks up any dirt and foreign material present at the surface. When the paraffin cools and hardens it forms a cast, which is taken off and processed with diphenylamine or diphenyl-