The exact weapon with which Anastasia was killed is unknown. Kelly Moffett testified that Byron Case had told her that he had obtained a "hunting gun" from his father's home,¹ but she did not see the weapon clearly when he shot Anastasia.² She further testified that the defendant discarded the weapon that night in an "industrial-looking area" near train tracks.³

While Moffett had difficulty fully describing the murder weapon, having only seen it briefly and not being well-versed in firearms, she did say definitively that it was a barreled weapon, ruling out a handgun.

Only a fragment of the projectile (56 grains, or 1/8 oz.) from the murder was recovered,⁴ leaving it impossible to identify the weapon or determine to a 100% certainty what kind of weapon it was, but the chances of it being a small handgun were virtually ruled out,⁵ with no chance of being a pellet shotgun.⁶

The significance of this is that Kelley Moffett, with no knowledge of the Medical Examiner's report, identified the murder weapon as being long-barreled, as opposed to a handgun. Handguns are much more common in murders, and had she claimed that the defendant had used a handgun (a much more likely scenario, had she been fabricating the story), the forensics evidence given (estimating the likelihood of a handgun at less than 10%)⁷ would have worked heavily in Case's favor.

Case and his supporters feel that a ballistics test "could have determined definitively whether the bullet had come from a pistol, rifle or shotgun", but this assertion is incorrect, considering the small fragment recovered. We must assume that they did not consult any experts when making their claim, but we are comfortable with the level of expertise and experience behind our answer.

The weapon most likely to fit the information given from testimony and forensic evidence is a .410 shotgun. The slug used in such weapons is about .39 inch in diameter (Anastasia's wound was described as "about 3/8 inch" or .375; as this was an approximation, the less than one millimeter difference is within tolerance of that), and weighing about 90 grains (about two-tenths of an ounce; the lead slug recovered at the scene was 56 grains, with the remainder having dispersed inside the skull). The .410 shotgun, occasionally known as a "squirrel gun" or "squirrel rifle", is a common "first gun" for young hunters; it is mostly utilized to shoot rabbits, squirrels, and other small game at fairly close range. It is occasionally used to shoot deer from short range. Fired from the range of less than six inches at a human skull, it is deadly. Its spread pattern, size, and firepower are consistent with Anastasia's fatal wound.

Further arguments have later been advanced by the killer's supporters that Anastasia may have been lying on her back when the shot that killed her was fired. The Jackson County Medical Examiner's report (page 2 of 7)⁸ noted that a small skull fragment was found about 18 inches to two feet (46 to 71 cm) away from the body; it seems impossible for a gunshot fired straight down at a subject lying on their back could make a fragment jump that far horizontally, and proponents of the "shot while lying down" theory have yet to explain that discrepancy.

Another argument has been made about terminology, arguing about the concept of being "blown back" by a gunshot. For the record, Kelly Moffett's statement under oath was as follows:

"He raised up the gun and shot her. It was a big loud noise. I screamed and turned away, but by the time I looked back, I could just see Justin like waving his hands. He just completely freaked out. And I looked over and Anastasia's body was back, like blown backwards, and I could see her feet."⁹

In other words, Kelly Moffett never said that Anastasia was "blown back" by the blast, but simply that Anastasia's body was back, like blown back. She did not see the shooting at the actual second, but turned away and screamed, and when she looked back, Ansastasia was lying on her back, whereas she had been standing a second before.

Those who made this argument either failed to read her testimony carefully, or chose to misinterpret it for their own purposes.