The state Supreme Court's Appellate Division ruled Anthony Marshall's 2009 conviction, which came in a case that shone a spotlight on New York society, was based on legally sufficient evidence. Appeals judges also rejected Marshall's argument that he should be spared prison because of his age, illness and service as a World War II veteran and U.S. ambassador.
"The record amply supports the jury's determination that Marshall committed a series of larcenous acts," the appellate judges wrote.
"We are not convinced that as an aged felon Marshall should be categorically immune from incarceration," they added.
Marshall was sentenced to one to three years in prison, but he was allowed to stay free on bail during the appeal. Tuesday's decision sent the case back to the trial judge for further proceedings, but it wasn't immediately clear whether Marshall would soon have to report to prison or whether he might appeal further and remain free on bail.
Marshall lawyer John Cuti said he was exploring Marshall's legal options, including more avenues for appeals.
"We are, of course, deeply disappointed in the decision," Cuti said.
Manhattan district attorney's office spokeswoman Erin Duggan said the case "underscored the importance of prosecuting elder abuse, particularly financial fraud perpetrated by those close to the victims."
The grand dame of the city's social elite before her death in 2007, Astor gave away huge amounts of money she inherited from her third husband, Vincent Astor. He was a great-great-grandson of real estate and fur magnate John Jacob Astor, one of the United States' first multimillionaires.
Her philanthropy was recognized with the Presidential Medal of Freedom, the nation's top civilian honor, in 1998.
Her son - a former ambassador, author and Broadway producer who was awarded the Purple Heart after being wounded at Iwo Jima - was convicted of exploiting Astor's dementia to help himself to millions of dollars of her $200 million fortune, engineer changes to her will and even take artwork off her walls after she was diagnosed with Alzheimer's disease. Astor was 105 when she died.
At a trial that featured Henry Kissinger and Barbara Walters as witnesses, Marshall said through his lawyers that he stole nothing. He had legal authority for the gifts he gave himself from her money during her lifetime, and she lucidly and intentionally changed her will to benefit her only child, they said.
The appeal raised those issues and another that caused a stir during the jury's deliberations: a juror's assertion that she felt threatened by another juror's remarks during deliberations.
The trial judge urged jurors to be civil and when the verdict was announced in court, the juror said she agreed with it. However, she later told a defense investigator she signed onto it because she felt demoralized.
Marshall's lawyers said the trial judge at least should have interviewed the jurors individually; prosecutors said he was right not to look into the deliberations. The appeals judges said interviewing jurors would have been "the more prudent course of action," but they said state Supreme Court Justice A. Kirke Bartley acted within his discretion in declining to do so.
"The problems appeared to resolve themselves, and there is no reason to believe that the ultimate unanimous verdict, confirmed by polling, was the result of coercion," the appellate court wrote.
Marshall's lawyers also asked the appeals court simply to show him mercy, under a state law provision for courts to overturn jury verdicts "in the interest of justice."
Marshall attended the appeals court arguments in a wheelchair in December and had health issues surface at his trial: a mini-stroke and a fall in a courthouse restroom. His lawyers said prison could kill him.
The appeals judges did throw out one part of Marshall's conviction, a grand larceny count involving work he had his mother's social secretary do for a theater production company he was running. But the appeals judges upheld the guilty verdicts on other charges, including one that carried a mandatory jail term.
The appellate court also upheld co-defendant Francis X. Morrissey Jr.'s conviction on charges of forging Astor's signature on a change to her will. Morrissey was a now-disbarred trusts and estates lawyer.
His appeal argued that if the signature was bogus, Morrissey didn't know. His lawyer, William Zabel, didn't immediately return a phone message Tuesday.