Robert Guarante 1968 Booking Photo

Robert Gentile's connections with Robert Guarante, a bank robber seen above with a shirt over his head after an arrest in Natick, Mass., in 1968, intrigued federal authorities investigating the theft of half a billion dollars in art from Boston's Isabella Stewart Gardner Museum in March 1990. (William Rye / The Boston Globe)

Gentile met Merlino at least once: He was with Guarente when he stopped by the garage to talk about having work done on his car, according to a source who knows all three men.

Merlino and his crew were on the FBI's list of Gardner suspects in the 1990s, according to filings in federal court. The legal filings and FBI reports show that, by 1997, the FBI had inserted two informants in Merlino's operation. Over the next year, the informants reported that Merlino treated Guarente like a partner. They also reported that Merlino talked as if he might have access to the stolen art.

In one of the FBI reports, an informant said it appeared to him that Merlino "was getting the authorization to do something with the stolen paintings." A lawyer with knowledge of a variety of Gardner cases said the informant reports, collectively, suggest Merlino was trying to take possession of the paintings.

Merlino also was meeting, according to FBI reports and other legal documents, with two younger men: robbery suspect David Turner, who was Guarente's driver; and, less frequently, with Stephen Rossetti, Guarente's nephew. When he was questioned by the FBI, Gentile was asked to identify Turner from photographs, said a source familiar with the investigation.

While looking for the stolen paintings, the FBI learned that Merlino and the two younger men were planning to rob an armored car depot. Agents intercepted and arrested the men on their way to the depot in early 1999. An FBI agent later testified in court that, immediately after the depot arrests, he tried to question the three about the Gardner heist. They refused to talk.

The three robbers argued unsuccessfully that the FBI, through its informants, created a conspiracy to rob the depot to leverage them to talk about the stolen art. Gentile's lawyer failed when making the same claim in court about his drug and gun indictments.

The Philadelphia Connection

Guarente also introduced Gentile to Robert Luisi, the Boston mobster who a federal prosecutor said sponsored Gentile and Guarente for membership in the Philadelphia mafia — a city where the FBI said some of the stolen Gardner art was taken.

Luisi had tried to join, but was not accepted by, the New England mafia, an associate said. Philadelphia agreed to accept him when he reached out through a man he met in prison. He agreed and, according to court filings, became the boss, or capo, of the Philadelphia mob's Boston crew.

Guarente became Luisi's second in command and Gentile became a soldier in his crew, according to a prosecution court filing.

As it turned out, Philadelphia's Boston crew collapsed within months of being created. Within a year, Luisi had been indicted in a cocaine conspiracy. Worse for Gentile, Luisi agreed to cooperate with the government.

Gentile's lawyer said in court that Luisi lied to curry favor with the FBI.

During his interviews with the FBI, Luisi said Gentile and Guarente committed robberies together. He said they lived with him for a while in Waltham, Mass., while acting as his armed bodyguards.

Luisi told the FBI that Gentile always armed himself, usually with a snub nose .38-caliber revolver and a .22-caliber derringer. He said Gentile gave him a silencer for his own handgun.

The FBI found a half dozen silencers in Gentile's cellar, as well as two snub nose, .38-caliber revolvers and a .22-caliber derringer, according to a government legal filing.

Luisi said that, in the late 1990s, Gentile was planning the robbery of an armored car carrying cash from a casino in Ledyard and that Luisi had introduced him to a crew of Charlestown robbers who could help, a federal prosecutor said in court.

It was Luisi who told the FBI that said Gentile's nickname was "The Cook."

Gentile acknowledges using the name "The Cook," according to a government court filing. But his lawyer said he denies almost everything else.

He acknowledges working for Luisi, but said he was paid what amounted to small change for cooking and running card games, his lawyer said. Another source who knew Luisi in the late 1990s said "Luisi had apartment where they hung out and Gentile would cook. Gentile was the cook and the bodyguard."

Within a year of Gentile's alleged induction in the mafia, his network in Boston was in disarray.