Following his arrest in 1993, Casso became one of the highest-ranking members of the Mafia to turn informer. In 1998, however, the US government rescinded Casso's plea agreement and dropped him from the witness protection program. Later that year, a federal judge sentenced him to 455 years in prison.
Born in South Brooklyn, Casso was the youngest of the three children of Michael and Margaret Casso (née Cucceullo). Each of Casso's grandparents had emigrated from Campania, Italy, during the 1890s. His godfather was Salvatore Callinbrano, a made man and caporegime in the Genovese crime family, which maintained a powerful influence on the Brooklyn docks. Casso dropped out of school at 16 and got a job with his father as a longshoreman. As a young boy, he became a crack shot, firing pistols at targets on a rooftop which he and his friends used as a shooting range. Casso also made money shooting predatory hawks for pigeon keepers. Casso stood at 5'6 and weighed 185 pounds.
Casso was a violent youth and member of the infamous 1950s gang, the South Brooklyn Boys. In 1958, he was arrested after a "rumble" against Irish-American gangsters. Casso later told biographer Philip Carlo that his father visited him at the police station and tried in vain to scare his son straight. He soon caught the eye of Christopher "Christie Tick" Furnari, the capo of the "19th Hole Crew" in the Lucchese family. Casso started his career in the Mafia as a loanshark. As a protégé of Furnari, he was also involved in gambling and drug dealing. He was arrested for attempted murder in 1961, but was acquitted when the alleged victim refused to identify him. He would not see the inside of a cell again for over 30 years.
Over the years, there have been various stories of how Casso got the nickname "Gaspipe." Even though he detested the nickname, it stuck to Casso for life and though few would say it to his face, he allowed some close friends to call him "Gas".
During the 1970s, Casso was one of a string of Mafia associates who were suspected of turning informant for the US government. In 1974, at age 32, he became a made man, or full member, of the Lucchese family. Casso was assigned to Vincent "Vinnie Beans" Foceri's crew that operated from 116th Street in Manhattan and from Fourteenth Avenue in Brooklyn. Shortly after becoming made, Casso became close to another rising star in the family, Victor Amuso, and began a partnership that would last for two decades. They committed scores of crimes, including drug trafficking, burglary and the murders of informants. When Furnari became the Lucchese consigliere, he asked Casso to take over the 19th Hole Crew. However, Casso declined, suggesting that Amuso be promoted instead. Casso opted to become Furnari's aide; a consigliere is allowed to have one soldier work for him directly.
In December 1985, Casso was approached by Gambino family capo Frank DeCicco regarding a planned coup in his own family. John Gotti, another Gambino capo whose crew had been implicated in drug deals, was planning to kill his boss Paul Castellano and take over the Gambinos, and was looking for support among the acting bosses-in-waiting of the crime families affected by the Mafia Commission Trial. According to Sammy Gravano, another of Gotti's co-conspirators who would later turn state's evidence, Casso offered the conspirators his support. Casso himself would claim he tried to talk DeCicco out of participating in the coup, warning him that, without official sanction from the Commission, all the participants would be murdered in revenge. The hit went ahead regardless on December 16; Casso would later denounce Gotti's actions to Carlo as "the beginning of the end of our thing."
As Casso had warned, Lucchese boss Anthony Corallo and Genovese boss Vincent Gigante decided to kill Gotti and DeCicco, his new underboss, in revenge. Amuso and Casso were chosen to handle the assassinations, and were instructed to use a bomb to try and shift suspicion to Sicilian mobsters or Zips based in the US. While American mafiosi have long been (officially) banned from using bombs due to the risk of collateral damage, Sicilian mafiosi were notorious for blowing up their targets. Amuso and Casso made one attempt on the lives of Gotti and DeCicco, planting a bomb in DeCicco's car when the two were scheduled to visit a social club on April 13, 1986. Gotti cancelled at the last minute, however, and the bomb instead only killed DeCicco and injured a passenger they had mistaken for Gotti.
In the autumn of 1986, Corallo sensed that the Commission Trial would result in a guilty verdict that would ensure the entire Lucchese leadership would die in prison. Wanting to maintain the family's half-century tradition of a seamless transfer of power, Corallo endorsed Casso as his successor. However, Casso turned it down and instead suggested that Amuso become new boss. Amuso formally took over the family in 1987, and Casso succeeded Furnari as consigliere. Amuso named him underboss in 1989 after Mariano Macaluso retired. However, Casso wielded as much influence as Amuso. According to federal and state investigators, Amuso attended to policy issues and representing the family at Commission meetings, leaving day-to-day control of the family to Casso.
During this time, Casso maintained a glamorous lifestyle, wearing expensive clothes and jewelry, running restaurant tabs up to thousands of dollars, owning a mansion in an exclusive Brooklyn neighborhood and going on huge spending sprees. While at the top of the Lucchese family, Amuso and Casso shared huge profits from their family's illegal activities. These profits included: $15,000 to $20,000 a month from extorting Long Island carting companies; $75,000 a month in kickbacks from eight air freight carriers that guaranteed them labor peace and no union benefits for their workers; $20,000 a week in profits from illegal video game machines; and $245,000 annually from a major concrete supplier. Amuso and Casso also split more than $200,000 per year from the Garment District rackets, as well as a cut of all the crimes committed by the family's soldiers.
In one instance, Casso and Amuso split $800,000 from the Colombo family for Casso's aid in helping them rob steel from a construction site at the West Side Highway in Manhattan. In another instance, the two bosses received $600,000 from the Gambino family for allowing them to take over a Lucchese-protected contractor for a housing complex project on Coney Island. Casso also controlled Greek-American gangster George Kalikatas, who gave Casso $683,000 in 1990 to operate a loan sharking and gambling operation in Astoria, Queens.
Casso had a close alliance with Ukrainian boss Marat Balagula, who operated a multibillion-dollar gasoline bootlegging scam in Brighton Beach. Balagula, a Soviet Jewish refugee from Odessa, had arrived in the US under the Jackson-Vanik Amendment. After Colombo capo Michael Franzese began shaking down his crew, Balagula approached Furnari and asked for a sit-down at the 19th Hole Crew's social club in Brooklyn. According to Casso, Furnari declared,
"Here there's enough for everybody to be happy...to leave the table satisfied. What we must avoid is trouble between us and the other families. I propose to make a deal with the others so there's no bad blood...Meanwhile, we will send word out that from now on you and your people are with the Lucchese family. No one will bother you. If anyone does bother you, come to us and Anthony will take care of it."
Street tax from Balagula's organization was not only strategically shared, but also became the Five Families' biggest moneymaker after drug trafficking. According to Carlo,
"It didn't take long for word on the street to reach the Russian underworld: Marat Balagula was paying off the Italians; Balagula was a punk; Balagula had no balls. Balagula's days were numbered. This, of course, was the beginning of serious trouble. Balagula did in fact have balls – he was a ruthless killer when necessary – but he also was a smart diplomatic administrator and he knew that the combined, concerted force of the Italian crime families would quickly wipe the newly arrived Russian competition off the proverbial map."
Shortly afterward, Balagula's rival, a fellow Russian immigrant named Vladimir Reznikov, drove up to the former's office building in the Midwood section of Brooklyn. Sitting in his car, Reznikov opened fire on the building with an AK-47. One of Balagula's close associates was killed and several secretaries were wounded. Then, on June 12, 1986, Reznikov entered the Rasputin nightclub in Brighton Beach and placed a 9mm Beretta against Balagula's head, demanding $600,000 in exchange for not pulling the trigger. He also demanded a percentage of everything Balagula was involved in. After Balagula promised to get the money, Reznikov threatened him and his family.
Shortly after Reznikov left, Balagula suffered a massive heart attack. He insisted on being treated at his home in Brighton Beach, where he felt it would be harder for Reznikov to kill him. When Casso arrived, he listened to Balagula's story and seethed with fury. Casso later told Carlo that, to his mind, Reznikov had just spat in the face of the entire Cosa Nostra. Casso responded, "Send word to Vladimir that you have his money, that he should come to the club tomorrow. We'll take care of the rest." Balagula responded, "You're sure? This is an animal. It was him that used a machine gun in the office." Casso responded, "Don't concern yourself. I promise we'll take care of him...Okay?" Casso then requested a photograph of Reznikov and a description of his car.
The following day, Reznikov returned to the nightclub to pick up his money. Upon realizing that Balagula wasn't there, Reznikov launched into a barrage of profanity and stormed back to the parking lot. There, he was shot dead by DeMeo crew veteran Joseph Testa, who jumped into a car driven by Anthony Senter and left Brighton Beach. According to Casso, "After that, Marat didn't have any problems with other Russians."
On July 29, 1991, due to a tipoff from an unidentified Lucchese insider, Amuso was arrested and Casso was secured the de facto boss of the family. It has been speculated that Casso himself was the source for the leak, as only a few people were privy to Amuso's location. This theory is contradicted, however, by Carlo, who states that Casso had no desire to be boss of the Lucchese family and attempted to arrange for Amuso's escape from federal custody after his arrest. To the disappointment of Casso and the Lucchese capos, Amuso refused to leave prison out of fear for his life. As a result, the Lucchese capos asked Casso to take over as acting boss. Casso reluctantly accepted.
While evading authorities for over three years, Casso maintained control over the Lucchese family. In the process, he ordered eleven mob slayings, as well engineering a murder plot against Gotti with Genovese leader Vincent "the Chin" Gigante. Casso and Gigante were deeply disgusted that Gotti's murder of Castellano without the sanction of the Commission. All attempts on Gotti's life were stymied, however, by the constant presence of news reporters around the Gambino boss.
In early 1991, Amuso and Casso ordered the murder of capo Peter Chiodo, a fellow Windows Case defendant who had pleaded guilty without the family's approval. Chiodo barely survived an assassination attempt and subsequently agreed to turn state's evidence. In September that year, acting boss Al D'Arco, convinced Casso had marked him for death following his failure to kill Chiodo, also surrendered and agreed to testify. Both of these defections opened the door for new murder indictments against Amuso and Casso. In another incident in 1993, Casso used Brooklyn faction-leaders George Zappola and Frank "Bones" Papagni, as well as Lucchese consigliere Frank "Big Frank" Lastortino, to kill former underboss and Bronx faction leader Stephen "Wonderboy" Crea. However, due to the massive indictments at the time, all members of the plot, including Casso, were eventually incarcerated on various charges. Casso was arrested at a mistress's home in Mount Olive, New Jersey, on January 19, 1993.
Casso was held at New York's Metropolitan Correctional Center pending trial. Facing charges that would have all but assured he would die in prison, he began making escape plans. One plan almost succeeded when a bribed guard cleared him through security; Casso nearly walked out of jail, but was spotted by another guard and thwarted at the last minute. Afterwards, Casso began making plans for Lucchese members to find out what prison buses would be transporting him and arrange an ambush, as well as assassinating the presiding judge, Eugene Nickerson, to buy himself more time.
However, all of this came undone when Amuso not only stripped Casso of his title of underboss, but declared that all Lucchese mafiosi should consider him a pariah—in effect, banishing Casso from the family. Amuso had long been suspicious of Casso's failure to use his law enforcement contacts to find out who betrayed him, and finally concluded Casso did it himself to take control of the family. With D'Arco, Acceturo, and Chiodo due to be star witnesses against him, Casso offered to become a federal witness just before his trial was due to begin. He finalized a deal at a hearing on March 1, 1994, where he pleaded guilty to all 72 counts he had been indicted on, now including 15 murders.
Casso disclosed that two retired NYPD detectives had been on the Lucchese payroll. These detectives were later determined to be Louis Eppolito and Stephen Caracappa, who committed eight of the eleven murders Casso had ordered. Carracappa and Eppolito had also given Casso information which led to many others as well, revealing the names of potential informants. They were subsequently found guilty on all charges and sentenced to life in prison. However, when Casso revealed that he also had an FBI agent on the payroll, prosecutors ordered him to keep quiet. Casso further enraged the US government by accusing Gambino turncoat Sammy Gravano of committing multiple felonies which he had later denied on the witness stand. Casso claimed to have sold large amounts of cocaine, heroin, and marijuana to Gravano over two decades. Once again, no one was interested. However, Casso was vindicated to some extent when Gravano pleaded guilty in 2000 to operating a massive narcotics ring, which included selling ecstasy to adolescents.
In 1997, Casso was thrown out of the Witness Protection Program. Prosecutors alleged numerous infractions, including bribing guards, assaulting other inmates and making "false statements" about Gravano and D'Arco. Casso's attorney tried to get Judge Frederic Block to overrule federal prosecutors in July 1998, but Block refused to do so. Shortly afterward, Judge Block sentenced Casso to 455 years in prison without possibility of parole—the maximum sentence permitted under sentencing guidelines. Casso later told New York Times organized-crime reporter Selwyn Raab that, before turning informer, he was seriously considering a deal that would have allowed him the possibility of parole after 22 years. "I help them and I get life without parole," he said. "This is really a fuckin' joke."
In a 2006 letter to Carlo, Casso declared,
"I am truly regretful for my decision to cooperate with the Government. It was against all my beliefs and upbringing. I know for certain, had my father been alive, I would never have done so. I have disgraced my family heritage, lost the respect of my children and close friends, and most probably added to the sudden death of my wife and confidant for more than 35 years. I wish the clock could be turned back only to bring her back. I have never in my life informed on anyone. I have always hated rats and as strange as it may sound I still do. I surely hate myself, day after day. It would have definitely been different if the Government had honest witnesses from inception. I would have had a second chance to start a new life, and my wife Lillian would still be alive. It seems that the only people the Government awards freedom to are the ones who give prejudiced testimony to win convictions. 'The Truth Will Set You Free,' means nothing in the Federal courts. Even at this point in my life I consider myself to be a better man than most of the people on the streets these days."
Casso began serving his sentence at the supermax prison ADX Florence in Florence, Colorado. According to the Federal Bureau of Prisons, Casso was transferred to the Federal Medical Center (FMC) at the Federal Correctional Complex in Butner, North Carolina for the treatment of prostate cancer in March 2009. He was returned to ADX Florence in July 2009. By 2013, Casso had been transferred to the Federal Residential Reentry Management Office in Minneapolis, Minnesota. This is not a prison facility, but rather an administrative designation for inmates assigned to home confinement, "halfway houses", or state and county correctional facilities.
Casso married fellow South Brooklyn native Lillian Delduca on May 4, 1968. They had a daughter and son. Despite knowing about his many infidelities, Lillian Casso continued to support her husband until her death in February, 2005.
In an interview with Carlo, Casso recalled,
"Most all men in my life, everyone I know, had girlfriends. It goes with the territory. Women are drawn to us, the power, the money, and we're drawn to them. But only in passing. Some guys treated their mistresses better than their wife, but that's a fuckin' outrage. No class. Only a cafone does that. I never loved any woman but Lillian. She and my family always came first."