"The arrest of Henry Hill was a price beyond measure," Pileggi wrote." ''Hill had grown up in the mob. He was only a mechanic, but he knew everything. He knew how it worked. He knew who oiled the machinery. He knew, literally, where the bodies were buried. If he talked, police knew that Henry Hill could give them the key to dozens of indictments and convictions."
Hill's testimony sent dozens of men to prison, many for the Lufthansa heist, and he and his wife Karen, played by Lorraine Bracco in the movie, went into hiding together, spending years fearing retribution by a gun to the back of his head from his old colleagues.
In the early 1990s, after more drug arrests, Hill was booted from the witness protection program.
His fears for his life waned as many former associates died off, and he led a more public life in later years, appearing in documentaries and becoming a popular call-in guest on Howard Stern's radio show.
His death was first reported by the celebrity website TMZ.
His struggles with substances would continue for most of his life. In 2008 he pleaded guilty in San Bernardino, Calif., to two counts of public intoxication. In 2009, he was arrested in an Illinois suburb of St. Louis on charges of disorderly conduct and resisting arrest.
"I've been on every drug humanly possible, and I can't get a handle on alcohol," he told The Associated Press in 2009. "I'll go two, two and a half years, and I don't know what triggers me."
Hill summered in Southern California at an extremely modest one-story house in the Topanga Canyon area of the Santa Monica Mountains, with an expansive backyard view of the San Fernando Valley.
Sitting on the back porch, Caserta, 52, and her son, Nate, 24, described the contemporary Hill as a man who maintained a mobster's air of self-assurance and confidence but regretted his gangster past.
An avid painter who contributed his artwork to auctions, he gave money to causes ranging from local police cadets to the homeless, and every Thanksgiving for five years he would dish out food to the poor, said Caserta and her son.
She said Hill was not impressed by wealth or celebrity.
"He had it all twice," she said, referring to his years as a gangster and later as a celebrity.
Her son added: "He cared about family. He didn't care about all that stuff."
Caserta said that Hill, who also had a home in Connecticut, is survived by three sisters, a brother, three children and four grandchildren. She said she could not give their names because they are in witness protection.
Funeral plans were being arranged.
Associated Press Writer Shaya Mohajer contributed to this report.