The son of the late philanthropist Brooke Astor has been charged with stealing from the Astor fortune as his mother succumbed to her advanced age.

The indictment that was announced yesterday against Anthony Marshall, 83, comes more than a year after Mr. Marshall’s own son, Philip, accused his father of failing to adequately care for Astor. The criminal charges brought by the Manhattan district attorney, Robert Morgenthau, ensure that Astor’s final years will come under renewed scrutiny.

Astor died in August at 105 after living with Alzheimer’s disease for several years, during which she changed her will several times. Before her death, a state court judge had ruled that Astor’s grandson’s claim that she was not getting her needed medical care or creature comforts were unfounded.

RELATED: Copy of the Indictment (pdf)

The indictment yesterday charges Anthony Marshall and a lawyer close to him, Francis Morrissey, 65, with several felonies, including a “scheme to defraud” Astor. At the center of the indictment is the allegation that the two pressured Astor into changing her will twice in 2004 in order to give Mr. Marshall control over tens of million of dollars that earlier wills had pledged to charity. A lawyer other than Mr. Morrissey, whom prosecutors have neither identified nor charged with a crime, drafted these later versions of the will. One change to the will involved a forgery of Astor’s signature, prosecutors allege. Although the indictment rules out Mr. Marshall as the forger, prosecutors have not said whether Mr. Morrissey or someone else actually signed in Astor’s hand.

The indictment also alleges that Mr. Marshall committed larceny by using his mother’s money to pay wages to his social secretary and the captain of his yacht, as well as to increase his own salary for managing her affairs to $1.4 million from $450,000.

To raise cash from the Astor fortune — valued at just shy of $200 million — Mr. Marshall resorted to “falsely informing his mother that she was running out of money to induce her to sell” paintings, Mr. Morgenthau said at a press conference. The paintings prosecutors say were sold illegally were works of Childe Hassam, Giovanni Domenico Tiepolo, and John Frederick Lewis.

Mr. Morrissey’s alleged role is limited to the two amendments to the will and did not extend to the sale of artwork. Prosecutors said his motive was the higher executor fees he stood to gain under the final amendment to the will.

Mr. Marshall pleaded not guilty in court yesterday and was released on a $100,000 bond. Any jury would likely have difficulty squaring the allegations named in the indictment with Mr. Marshall’s accomplished life as a diplomat and theater producer.

Mr. Marshall’s attorney, Kenneth Warner, said his client had “effectively managed his mother’s affairs for more than 25 years, increasing the value of her investments from $19 million to $82 million.

Brooke Astor loved Tony, her only child, and whatever he received was in accordance with her wishes,” Mr. Warner said in a statement.

A lawyer for Mr. Morrissey, Michael Ross, told the New York Times his client would plead not guilty and “vigorously denies having acted improperly.”

Mr. Morrissey is not currently in the country, a source said.