Brooke Astor's son has moved to dismiss the criminal case against him. It seems the thrust of his defense is going to be that the prosecution "cherry-picks" through a "clear pattern of well-informed generosity toward her only child" to allege that "other money and items that were transferred to Mr. Marshall at around the same time were obtained by fraud or theft." According to the New York Times:
"The filing, for instance, cites a charge of grand larceny in the 18-count indictment that refers to a $2 million commission Mr. Marshall collected from his mother for selling a Childe Hassam painting of hers. Prosecutors have said that Mr. Marshall made misrepresentations to Mrs. Astor that her finances were dwindling and consequently induced her to sell the work of art, enabling him to collect his large fee. But the [filing] also cites a conversation that a witness heard in which Mrs. Astor responded to Mr. Marshall, telling him to take $1 million and to give another $1 million to his wife."
Background here.