Plenty of spy movies in those Cold War days. Not hard to glean a few techniques. Books on the subject as well.
Where did you come up with 'equally' possible? 55 years and still no supported evidence of Oswald being involved with anyone but his alter ego and Marina's laughter at his self-importance, including parading around the back yard in his black ops-wannabe getup.
People who know far more about National Security than you and I have opinionated that Oswald didn?t act alone. Those include:
- Father of the Warren Commission, Lyndon Johnson
- Robert Kennedy
- Sen. John Kerry
Plus a few former CIA agents like Brian Latell and Bob Baer
Those are just a few names that come to mind without researching
As far as spycraft, maybe he learned it in the Marines where he learned Russian. That?s the most likely place.
Or maybe he learned a few things living in the USSR.