http://en.wikipedia.org/wiki/Joseph_P._Kennedy,_Sr.

In the 1920s Kennedy made huge profits from reorganizing and refinancing several Hollywood studios, ultimately merging several acquisitions into Radio-Keith-Orpheum (RKO) studios.[2]

After Prohibition of alcohol ended in 1933, Kennedy consolidated an even larger fortune when he traveled to Scotland with FDR's son, James Roosevelt, to buy distribution rights for Scotch whisky. His company,× Importers, became the exclusive× American agent for Gordon's Gin and Dewar's Scotch. In addition,× Kennedy purchased spirits-importation rights from Schenley Industries, a firm in Canada.[2] He owned the largest office building in the country, Chicago's Merchandise Mart, giving his family an important base in that city and an alliance with the Irish-American political leadership there.

There is no evidence that Kennedy Sr. was a bootlegger

Rather he used his friendship with Roosevelt and his political connections to do business after Prohibition, flooding the usa with quality liquor, in the 20s became rich thanks to the stock market.

Scalish about his sons, Kennedy Sr. had ties with the Patriarcas, and in any case don't think to the karma, if you do business with certain people and you promise certain things, it's normal that if you don't keep your promises, it's normal that you should expect a reaction.

John and Bobby knew that his father had made certain promises to the Mafia?
if yes,they thought to be safe and untouchable? they didn't know that had been killed three presidents before JFK?
John, Bobby and their father have sinned omnipotent thinking they are invincible and we know what happened.