At the risk of stirring up a hornet's nest,let me throw my two cents in. When you consider the actual evidence,not speculation,hearsay,or out of context quotes,but evidence,there is no doubt that Oswald was a lone nut,and the sole assassin of JFK.
Much of what is out there as far as conspiracy theory,is the result of people repeating,not researching. When you actually look into what is documented as opposed to what is exaggerated,the guilt of Oswald is indisputable,as is the absolute lack of any credible conspiracy evidence.

The Mob could never have successfully pulled this off and kept it quiet,not in a million years,and no one else had a motive that would necessitate the public murder of the President.

If they were so powerful and able to infiltrate the highest levels of our government and intelligence community,JFK would have just died in his sleep,or from a swift and fatal disease. There is no purpose to be served by killing him in front of the nation.
Bottom line,look at each of the main elements of the "conspiracy" with an open mind,examining both sides,and the conclusion is inescapable. Lone nut,lone shooter.