Robert Gentile, who authorities say is the last surviving person of interest in the 1990 art heist from the Isabella Stewart Gardner Museum in Boston, is brought into the federal courthouse in a wheelchair for a hearing in Hartford, Conn. on April 20, 2015.
Robert Gentile, who authorities say is the last surviving person of interest in the 1990 art heist from the Isabella Stewart Gardner Museum in Boston, is brought into the federal courthouse in a wheelchair for a hearing in Hartford, Conn. on April 20, 2015. Credit: AP file

A reputed Connecticut mobster who authorities say is the last surviving person of interest in the largest art heist in U.S. history pleaded guilty Thursday to unrelated weapons charges.

Robert Gentile, 80, appeared in federal court in Hartford in a case stemming from federal agents’ seizure of firearms and ammunition from his Manchester home. The plea deal calls for him to serve about three to six years in prison. Sentencing is set for August 25.

Prosecutors have said they believe Gentile has information about the still-unsolved 1990 heist at the Isabella Stewart Gardner Museum in Boston. Thieves broke in and stole an estimated $500 million worth of artwork, including works by Rembrandt, Edouard Manet, Edgar Degas and Johannes Vermeer.

Gentile has denied knowing anything about the heist or the paintings, and the artwork did not come up in court Thursday.

Prosecutors, however, have said another gangster’s widow claimed her husband gave Gentile two of the paintings. Authorities also have said that Gentile talked about the stolen paintings with fellow prisoners and once told an undercover FBI agent he had access to two of the paintings and could negotiate the sale of each for $500,000.

Gentile, who has gray hair and a gray beard, appeared in court in a wheelchair and wore a white T-shirt and beige prison pants. He talked about his and his wife’s health problems in court before the proceedings began. He said his wife recently fell and broke her shoulder.

“I just wish I could get out and see her,” he said in comments to the prosecutor and his lawyer. “She’s my whole life … So don’t go too hard on me.”

His lawyer, A. Ryan McGuigan, said Gentile hasn’t disclosed to him any information about the heist or the paintings, not even when he visited Gentile when Gentile lay near death in a prison hospital several months ago. Gentile has since recovered.

“That led me to believe that he certainly doesn’t have any knowledge about where the paintings are, nor does he have any knowledge of who may have them,” McGuigan said outside the courthouse.