Holland v. State, 268 So.2d 883 (Ala. Crim. App. 1972)

"The substance of the testimony as to the identification of the gun as the one that the particular 32 slug was fired from, was that a pistol barrel makes a mark, peculiar to that weapon, on a bullet fired from it and upon the matching marks on the bullet taken from the body and the one test fired from the pistol, his opinion was based. When the pistol is shown directly, or by reasonable inference, to have been in the possession of the appellant shortly after the difficulty, this is enough to allow the introduction of the above mentioned expert testimony."