Oswald needed no encouraging, he had tried to kill General Edwin Walker months earlier and suggested to his wife with a young child that they hijack a plane and take it to Cuba, this is Oswald.
As for Communists killing 100 Million in the 20th Century, try 300 Million.
I had always heard 100 million. Got a source for that? If I've been using the wrong number in arguments, I'd love to use the right number. While 300 million is mind-boggling, it would make my arguments better.