So basically hearsay piled on top of hearsay without a shred of evidence to support the assertion.

On the other hand we have... "Photographs of Oswald holding the rifle, a palmprint found upon examination of the rifle, and detective work tracing its sale, all eventually led to Oswald.[4] Marina Oswald later testified she was told by Lee that the rifle was also used before in an attempt to assassinate retired U.S. Army General Edwin Walker in Dallas." and "Also found in the same vicinity were three 6.5×52mm brass cartridges later proven to have been fired from Oswald's rifle. One of the empty cartridges, CE 543, was dented in the area of the neck. Ballistic experts testified to the HSCA that this likely occurred when the rifle was rapidly fired and the cartridge was ejected. When four test bullets were fired from the rifle, one of the four cartridges had a dented neck, similar to CE 543.[33]"...Sebastian Latona, supervisor of the Latent Fingerprint section of the FBI’s identification Division,[36] testified that the palm print found on the barrel of the rifle belonged to Lee Harvey Oswald. Experts agree that palm prints are as unique as fingerprints for the purpose of establishing identification...On the day that Kennedy was killed, Oswald was wearing a shirt of dark blue, grey-black and orange-yellow cotton fibers over a white T-shirt, the same type of fibers that were recovered from the rifle after close examination by experts.
In the crevice between the butt-plate and the wooden stock of the rifle, a tuft of several cotton fibers of dark blue, grey-black and orange-yellow shades were found.
After tests of the colors, shades, and weave patterns of the fibers found on the gun, Paul Stombaugh, a special agent of the FBI Laboratory's Hair and Fiber Unit, matched the fibers found on the gun to the fibers from Oswald’s shirt.[58]...During his Marine Corps service in December 1956, Oswald scored a rating of sharpshooter (twice achieving 48 and 49 out of 50 shots during rapid fire at a stationary target 200 yards [183 m] away using a standard issue M1 Garand semi-automatic rifle), although in May 1959, he qualified as a marksman (a lower classification than that of sharpshooter). Military experts, after examining his records, characterized his firearms proficiency as "above average" and said he was, when compared to American civilian males of his age, "an excellent shot".[59]

[en.wikipedia.org] Like it or not Oswald acted on his own and changed history forever with a used mail order rifle some cheap ammunition, and without any help from The Illuminati, or the Knights Templar, or the Mafia, or Castro etc.