It's actually one of the more plausible theories. Oswald was a disturbed ne'er-do-well who seems to have been hungry for attention any way he could get it. He initially wanted to kill the ultra right wing general Edwin Walker, but failed and later just happened to be living in Dallas when JFK visited.

Narratively, though, this isn't satisfying, which is a big reason, I think, why the conspiracies continue to flourish.

It's the only acceptable explanation. Even his wife was sure of it too until she realised she could make money off of conspiracy nuts.

Agree with all. The guy was a sniper trained by the US military; no surprise that he knew how to use a rifle with a sight.

Nat Geo did a documentary a few years back called "JFK: The Lost Bullet" that gave very compelling evidence that LHO was the lone shooter.