The Wrong Gun

“That is correct.”

“Could you describe that procedure for us?”

“Certainly,” Manning said. “I examined the bullets under a comparison microscope.”

“For the benefit of the jurors, just what is that?”

“It is a microscope on which two bullets can be magnified and compared at the same time.”

Steve smiled. “As one might expect, Mr. Manning. Can you give us a bit more information than that? For instance, just what is it that you are comparing on these bullets?”

“The rifling marks.”

“Rifling marks?”

“Yes. The scratches on the bullet made from the barrel of the gun.”

“Now we’re coming to it, Mr. Manning. Would you tell us please about these rifling marks?”

“Certainly.” Manning turned to the jury. “The barrel of each gun has its own individual scratches and imperfections. As the bullet travels through the gun barrel, these markings are etched onto the surface of the bullet. And each barrel is unique-that is to say, the markings on no two gun barrels are exactly the same. So by observing the markings on a bullet, it is possible to tell what gun it was fired from.”

“But not by comparing the bullet directly to the barrel of the gun?”

“No, of course not. That would be incredibly awkward. What you do is compare a bullet that you suspect was fired by a gun with a bullet known to be fired by that gun.”

“How do you obtain this known bullet? How do you make sure it has been fired by that gun?”

“You fire it yourself, of course.”

“And that is what you did in this case?”

“Yes. Of course.”

“You took the gun, People’s Exhibit Four, fired a bullet through it, and compared that bullet to the bullet, People’s Exhibit One?”

“Yes, I did.”

“With a comparison microscope?”

“That’s right.”

“And if I understand your testimony correctly, what you were doing was attempting to line up the scratches on the bullet made by the gun barrel, establishing an exact correspondence that would allow you to conclude that both bullets had been fired from the same gun?”

“That is correct.”

“You compared the bullets side by side?”

“Yes and no.”

“What do you mean by that?”

“The bullets are side by side. The image I’m looking at is not.”

“Then what is it?”

“The alignment is the same as if the bullets were superimposed one over the other. Although that is not the image I’m seeing. What I’m seeing is the top half of one bullet and the bottom half of the other bullet. In other words, if you think of the picture I am seeing as the image on a movie screen, you could draw a horizontal line halfway across the screen. The top half of the screen would show the image of one bullet. The bottom half of the screen would show the image of the other bullet. That is, in each case, half the bullet. The top half of the screen would show the front half of the bullet and the bottom half of the screen would show the back half of the bullet.”

“And how does this enable you to make your comparison?”

“The bullets are round, of course, and can be rotated. If the bullets were fired from the same gun, it is possible to rotate one bullet until it lines up exactly with the other bullet. In other words, so all of the scratches and indentations line up. So for all intents and purposes, it appears as if you were looking at one bullet.”

“I see,” Steve said. “And that is what you did in this case?”

“Yes, I did.”

“I see,” Steve repeated.

Steve paused a moment, looked around. In the back of the courtroom Tracy Garvin caught his eye. She raised her hand, gave him the thumbs up sign.

Steve took a breath, turned back to the witness. “All right, Mr. Manning,” he said. “Let’s refer to the bullet, People’s Exhibit One, as the fatal bullet, and the bullet you fired from the gun, People’s Exhibit Four, as the test bullet. Are you saying you were able to line these two bullets up on the comparison microscope so that each and every scratch on the fatal bullet lined up with each and every scratch on the test bullet?”

“No, I’m not,” Manning said.

“You’re not? Are you telling me the scratches did not line up?”

“Not each and every one.”

“Didn’t you just get through saying that that would happen if the bullets had been fired from the same gun?”

“Under ordinary conditions, yes. But these were not ordinary conditions. See, the barrel of the gun, People’s Exhibit Four, had been defaced.”

“Defaced?”

“Yes, it had been altered. Someone had taken a tool such as a rasp or file and scratched deep grooves onto the inside of the gun barrel. These grooves of course resulted in additional scratches on the test bullet that do not show up on the fatal bullet.”

Steve frowned. “Let me be sure I understand this. You’re saying the gun barrel was defaced after it had fired the fatal bullet?”

“Exactly.”

“In other words, sometime between the time the gun fired the fatal bullet and the time the gun came into your possession, the gun barrel had been altered?”

“That’s right.”

“Is there any way for you to tell when that was done?”

“No. Only within the time frames you just described.”

“I see. Now, can you tell me, in your opinion as an expert, why would someone deface a gun barrel? What would be the purpose of it?”

Vaulding started to stand up, thought better of it, sat back down again.

Manning smiled. “Obviously, so the gun could not be matched with the fatal bullet. It’s not that uncommon for criminals to alter the barrel of their guns after the guns have been used in the commission of a crime. It’s certainly not the first instance I’ve seen.”

“And you say the purpose of this is so the gun cannot be matched with the bullet?”

“That’s right.”

“However, in this case you were able to match the gun with the bullet.”

“Not without some difficulty.”

“Oh? You say you had some difficulty?”

“Objection, Your Honor.”

“Overruled. That’s exactly what he said. If he wants to clarify it, he can. Proceed, Mr. Winslow.”

“What do you mean, you had difficulty?”

“Just that. The fresh scratches on the gun barrel made it more difficult to line up the scratches that were already in existence when the fatal bullet was fired.”

“But you were able to line them up?”

“Yes, I was.”

“I see. And once you had achieved this alignment, did you photograph the result?”

“Yes, I did.”

“It’s standard practice to photograph the bullets on a comparison microscope?”

“Yes, it is.”

“You do it in every instance?”

Manning hesitated.