to the exclusion of all other weapons. Similarly, firearms identification experts are able to compare the markings left upon the base of cartridge cases and thereby determine whether both cartridges were fired by the same weapon to the exclusion of all other weapons. According to Frazier, such an identification "is made on the presence of sufficient individual microscopic characteristics so that a very definite pattern is formed and visualized on the two surfaces."140 Under some circumstances, as where the bullet or cartridge case is seriously mutilated, there are not sufficient individual characteristics to enable the expert to make a firm identification.141

After making independent examinations, both Frazier and Nicol positively identified the nearly whole bullet from the stretcher and the two larger bullet fragments found in the Presidential limousine as having been fired in the C2766 Mannlicher-Carcano rifle found in the Depository to the exclusion of all other weapons.142 Each of the two bullet fragments had sufficient unmutilated area to provide the basis for an identification.143 However, it was not possible to determine whether the two bullet fragments were from the same bullet or from two different bullets.144 With regard to the other bullet fragments discovered in the limousine and in the course of treating President Kennedy and Governor Connally, however, expert examination could demonstrate only that the fragments were "similar in metallic composition" to each other, to the two larger fragments and to the nearly whole bullet.145 After examination of the three cartridge cases found on the sixth floor of the Depository, Frazier and Nicol concluded that they had been fired in the C2766 Mannlicher-Carcano rifle to the exclusion of all other weapons.146 Two other experts from the Federal Bureau of Investigation, who made independent examinations of the nearly whole bullet, bullet fragments and cartridge cases, reached the identical conclusions.147

THE BULLET WOUNDS

In considering the question of the source of the shots fired at President Kennedy and Governor Connally, the Commission has also evaluated the expert medical testimony of the doctors who observed the wounds during the emergency treatment at Parkland Hospital and during the autopsy at Bethesda Naval Hospital. It paid particular attention to any wound characteristics which would be of assistance in identifying a wound as the entrance or exit point of a missile. Additional information regarding the source and nature of the injuries was obtained by expert examination of the clothes worn by the two men, particularly those worn by President Kennedy, and from the results of special wound ballistics tests conducted at the Commission's request, using the C2766 Mannlicher-Carcano rifle with ammunition of the same type as that used and found on November 22, 1963.