It was a way to come to terms with being a Capone and to help reshape the memory of him. “Some biographers thought they know more about my family than I do,” she says. “I had to correct that.”

Deirdre says she’s convinced Capone had “nothing to do with the St. Valentine’s Day Massacre,” the brutal 1929 execution of several gangsters with Capone’s rival, George “Bugs” Moran. Many historians say the killings were orchestrated by Capone from Miami.

The biographies portray a retired Capone whose conspicuous behavior on Palm Island led to his downfall. His parties were infamous, his confidants were shady, his lifestyle was extravagant. During his trial in the 1930s, witnesses revealed what Eig calls “Capone’s extravagant spending habits:” a weekly meat bill of $250, telephone bills up to $8,400, $12 silk underwear, $275 diamond belt buckles.

Legend has it that President Herbert Hoover, who wintered in the mansion of his friend J.C. Penney across the bay on Belle Isle in 1928, just before he was sworn in, was so annoyed by Capone’s parties that he declared the arrest of the mafia boss as a top priority and pressured the Internal Revenue Service to charge Capone with tax evasion.

Eig says he never found proof for this version. “We know that they lived in short distance from each other for some weeks in 1928,” he says. “But during my research I did not see any media account from the time confirming the party story.”

MacCarthy, the Chicago defender, has another possibility he discovered while researching for the retrial: that a neighbor who objected to Capone’s lifestyle happened to be a close friend of Hoover’s.

“At the time, it was all about getting Capone — no matter on what grounds,” he says.

Whatever the right story was, it ended for good on Jan. 25, 1947. “Dropped dead here,” Deirdre says, pointed to the floor of a second-floor bathroom. It was the morning of her 7th birthday. Capone, who had suffered a mini-stroke days before, took some laps in the pool. With the help of two male nurses, he went upstairs to shower.

When he stepped out he suffered a massive stroke. “He was instantly dead,” recalls Deirdre, who had returned to Chicago only days before.

Gawkers and reporters gathered at the main gate. When a station wagon pulled off, they followed the car carrying what they thought would be Capone’s corpse.

But Capone’s brother Ralph, Deirdre’s grandfather, had pulled a fast one. The corpse was still in the house. Only later would the family secretly bring it to Chicago. “Al had a phenomenal funeral. But nobody knew that,” Deirdre says.

Her visit to the time capsule nearly done, she pauses. Her eyes stop at the inconspicuous address plate with the number “93.” She smiles. Another memory.