"Allegedly"
No, not allegedly. It's part of her testimony. Oswald also had recon photos of Walker's home and gave Marina instructions on what to do if he was arrested or killed. It's a slam dunk. But if you believe that this was all made up, then why? By the time Oswald became associated with the Walker attempt, he was already dead, there would be no trial, and the authorities were satisfied with his guilt as the JFK assassin. Why would the conspirators need to link him to yet another crime? Risky and unnecessary at that point. And how do they get Marina to make up this story? If she was under some type of duress, then that no longer applies as she now freely expresses doubts as to Oswald's guilt. Why doesn't she clear this up as well?