- "If not, you can take your wife, your family, and your mistress and move them all to Las Vegas."
- ―Michael Corleone to Tom Hagen[src]
Judy Buchanan was from a wealthy family in New York. She had drifted after college and sometimes worked for an advertising agency in New York. Some time after this she was married to a man who beat her and she became a blackjack dealer.
She met Tom Hagen at a political fundraiser and they began an affair that lasted for years, longer even than Kay and Michael's entire marriage. She had a disabled son named Philip, whose welfare was supported by Tom. Tom also "remedied" the situation of her abusive husband by having him killed. She also began working for the Corleone family, mostly low level deals such as covertly delivering money.
In the early sixties, Judy became paranoid that she was going to be killed due to her Mafia connections, and had Tom supply her with weapons. Tom sent his associate Ritchie Nobilio, an arms enthusiast, who provided her with a small sidearm. However, Judy was soon killed in a struggle with Detective Robert Dantzler and his brother-in-law Vernon Rougatis, who had been hired (by an associate of Nick Geraci) to take compromising photos that would damage Hagen's reputation.
Tom was then framed for her murder in an extensive public investigation that captured the attention of the press and the public and was widely viewed as guilty despite his actual innocence. His affair being revealed also caused problems in his relationship with his wife Theresa, though they eventually reconciled.