Here is Marina's affidavit. Notice that it says: "Today at Police Station, they showed me a rifle."
It must have been the alleged murder weapon, right? What else would they have shown her? This would have been about 4 to 4:30 on Friday afternoon. Oswald may have been doing his first lineup. I don't think that they told him that his wife was there. Presumably, he would have asked to see her if she was. And whether she asked about seeing him, I don't know.
But, getting back to Oswald, we know that they asked him if he owned a rifle, and he said no. He said that he used to own one- in Russia, which is the same thing his wife when she first was asked. They didn't show him the rifle, but they did show him the Backyard photo, and he denied posing for it. He said it was trick photography and that he could show them how it was done.
Let's consider that if Oswald was innocent, and of course he was, there were only two possibilities concerning the rifle. Either he didn't own it, OR, he did own it, but he didn't use it. Either way, he'd tell the truth, right? Wouldn't you? If police suspected you of shooting someone, which you didn't do, but then they produced a weapon you owned, you'd admit to owning the weapon, right? You'd say, "Yes, that's my weapon, but I didn't use it to kill anyone. Somebody must have stolen it and done it to frame me." You wouldn't lie about owning the weapon, first because you're innocent, and you're not going to lie about anything. You have no need to, and that's because you're innocent. But second, you would also know that it would be futile to lie, that if it's your gun, they're going to be able to confirm it, and very likely your own wife would confirm it. So, you're simply not going to lie. Therefore, we have no reason to think that Oswald lied. Hence, since he said he didn't own that or any other rifle at that time, he must not have.
If they were able and willing to show the rifle to his wife, it makes no sense that they didn't show it to him. It would have been the perfect follow-up to his denial. "So, you're saying that this is not your rifle, and you have never seen it before." Let him commit to that. And then, after he denied it, they could have proceeded to the paperwork from Klein's Sporting Goods, where he supposedly ordered it, which, for some reason, was at their fingertips. There is no account of them presenting that to him either. Nor did they ask him about his alleged P.O. Box. It would have been a very reasonable question to ask him why he needed a P.O. Box. Whatever he was expecting to receive at the P.O. Box, why couldn't it be delivered to his home? And I strongly suspect that Oswald would have denied renting the P.O. Box as well. But, they didn't even ask him. So, as far as we know, they asked him if he owned a rifle, and he said no, but he used to own one. And they showed him the Backyard photo, showing him holding a rifle, and he denied that that was him and that he did that. And that's it. In 13 hours, there was no other discussion about the rifle.
Oswald denied owning a rifle. He denied bringing any rifle to work. He was never asked if he swiped paper and tape from the mailing station and made a bag from it. Just look at all they didn't tell him and show him. They could have showed him the rifle. They could have showed him the bag. They could sought to retrieve the bag he said he carried in with his lunch inside. They could have sought to retrieve the scraps from the lunch he claimed to have eaten. What do you figure? Wax paper? crusts of bread? an apple core? It should have all been in the trash can in the domino room if he was telling the truth. So, why didn't they look? Obviously, if they had found that, it would have meant that he was telling the truth, right? But, they didn't look. Columbo would have looked.
So, why didn't they show Oswald everything they had supporting their contention that he owned the rifle? Why were they so evasive about it? I think it's because they knew he was going to deny that it was his. Why give him a chance to deny it twice? And, he may have thought of something very adamant to say. But then, they did show him the Backyard photo, which had to have been brought to the police station at the same time Marina was brought there. And I would say that someone, who didn't know better, may have thought that showing him that photo would jar him into admitting that the rifle was his.
Of course, these are all speculations. We really don't know why they showed the rifle to his wife but not to him. So, why show it to his wife?
If you read her statement carefully, she NEVER says that Oswald owned a rifle. She says she was aware of "a" rifle being stored in the garage, wrapped in a blanket, but she never it was his, or that he was the one storing it. Eventually, of course, she said all the things they wanted her to say in a bizarre burst of fictional fabrication. But, on the 22nd, she didn't do that. Still, I have to assume that they showed her the rifle because they thought there was a chance that she would confirm it was his. She really didn't. She said it was like the rifle her husband had. How was it like it? It was dark like it. Isn't that true of practically all rifles? Then, she didn't recognize the sight. To me, it sounds like she was trying to be cooperative, but she really didn't have anything to tell them.
So, we are left with the simple fact that they showed the rifle to Marina but not to Lee, and it is very significant. It shows that the rifle was there and accessible. If they could show it to her, then they could show it to him. So, they were willfully and methodically choosing not to show him the rifle- because they thought that, with him, it could do more harm than good to show it to him- that is, to the case against him.