As the underboss, Gravano played a major role in prosecuting John Gotti, the crime family's boss, by agreeing to testify as a government witness against him and other mobsters in a deal in which he confessed to involvement in 19 murders.

Gravano played a key role in planning and executing Castellano's murder, along with John Gotti, Angelo Ruggiero, Frank DeCicco, and Joseph Armone.

[10] He quickly moved into racketeering, loansharking, and running a lucrative poker game in the back room of an after-hours club, of which he was part owner.

[11] In the early 1970s, Colombo soldier Ralph Spero, brother of Shorty, became envious of Gravano's success, fearing that he would become a made man before his son, Tommy.

He quit his construction job and went on a self-described "robbing rampage" for a year and a half alongside his Goombata Alexander "Allie Boy" Cuomo.

[5] Like his predecessor Carlo Gambino, Castellano favored emphasizing more sophisticated schemes involving construction, trucking, and garbage disposal over traditional street-level activities such as loansharking, gambling, and hijackings.

[5] Gravano's construction and other business interests soon earned him a reputation as a "big earner" within the Gambino organization and made him a multi-millionaire, enabling him to build a large estate for his family in rural Cream Ridge, New Jersey.

In March 1980, longtime Philadelphia boss Angelo Bruno, was assassinated by his consigliere, Antonio Caponigro, and his brother-in-law Alfred Salerno, without authorization from The Commission.

The Commission subsequently placed contracts on Caponigro's co-conspirators, including John "Johnny Keys" Simone, who also happened to be Bruno's cousin.

[15] In 1982, Frank Fiala, a wealthy businessman and drug trafficker, paid Gravano $40,000 to rent the Plaza Suite for a birthday party he was throwing for himself.

[9] Gravano was never charged for the crime; he had made a $5,000 payoff to the later discredited and disgraced New York Police Department homicide detective Louis Eppolito to ensure the investigation yielded no leads.

The FBI had bugged Ruggiero's house and telephone, and Castellano decided he needed copies of the tapes to justify his impending move to Dellacroce and the family's other capos.

[5][17] When Castellano was indicted for both his connection to Roy DeMeo's stolen car ring and as part of the Mafia Commission Trial, he learned his own house had been bugged on the basis of evidence from the Ruggiero tapes and he became livid.

Knowing it would be too risky to approach the other four bosses directly, the conspirators got the support of several important mobsters of their generation in the Lucchese, Colombo and Bonanno families.

[18] Gotti and Ruggiero then sought and obtained the approval of key figures from the Colombos and Bonannos, while DeCicco secured the backing of top mobsters aligned with the Luccheses.

[5] Not suspecting the plot against him, Castellano invited DeCicco to a meeting on December 16, 1985, with fellow capos Thomas Gambino, James Failla, Johnny Gamorana, and Danny Marino at Sparks Steak House in Manhattan.

The conspirators considered the restaurant a prime location for the hit because the area would be packed with bustling crowds of holiday shoppers, making it easier for the assassins to blend in and escape.

At Gotti's suggestion, the shooters wore long white trench coats and black fur Russian hats, which Gravano considered a "brilliant" idea.

[9] Gotti was imprisoned in May 1986 at the Metropolitan Correctional Center, New York, while awaiting trial on Racketeer Influenced and Corrupt Organizations Act (RICO) charges.

He relied heavily on Gravano, Angelo Ruggiero, and Joseph "Piney" Armone to manage the family's day-to-day affairs while he called the major shots from his jail cell.

Jury selection for the racketeering case began again in August 1986,[25] with Gotti standing trial alongside Gene "Willie Boy" Johnson (who, despite being exposed as an informant, refused to turn state's evidence[26]), Leonard DiMaria, Tony Rampino, Nicholas Corozzo and John Carneglia.

[36] Gotti, Gravano and LoCascio were often recorded by the bugs placed throughout the Ravenite (concealed in the main room, the first-floor hallway and the upstairs apartment of the building) discussing incriminating events.

At the same time, attorneys Bruce Cutler and Gerald Shargel were disqualified from defending Gotti and Gravano after prosecutors successfully contended they were "part of the evidence" and thus liable to be called as witnesses.

[56][57][58] On the stand, Gravano confirmed Gotti's place in the structure of the Gambino family and described in detail the conspiracy to assassinate Castellano, giving a full description of the hit and its aftermath.

[82] The FBI alleged that Peter Gotti ordered two Gambino soldiers, Thomas "Huck" Carbonaro and Eddie Garafola, to murder Gravano in Arizona in 1999.

[84] In February 2000, Gravano and nearly 40 other ring members — including his ex-wife Debra, daughter Karen, and Gerard — were arrested on federal and state drug charges.

In November 2003, Sammy and Karen were ordered to pay $805,713 as reimbursement for court costs and investigative expenses relating to an earlier drug ring judgment.

[86] On February 24, 2003, New Jersey state prosecutors announced Gravano's indictment for ordering the 1980 killing of NYPD detective Peter Calabro by murderer Richard Kuklinski.

[89] Gravano denied any involvement in Calabro's death and rejected a plea deal, under which he would have received no additional jail time if he confessed to the crime and implicated all his accomplices.

[94][95][96] In 2013, National Geographic Channel dramatized Gravano's ecstasy ring in a scene in the Banged Up Abroad episode "Raving Arizona", televised worldwide.