US prosecutors' fourth attempt in five years to convict the scion of New York's leading Mafia family culminated Monday with the charge that John Gotti Junior's claim to have gone clean is a 'sham.' 'The defendant's claim is a sham. It was made up with other mob members,' Assistant US Attorney James Trezevant said in Manhattan federal court during the final day of arguments before the racketeering and murder case goes to the jury. 'He embraced the violence and treachery,' the prosecutor said, and 'he has never, never quit that life.' Gotti is accused of involvement in three Cosa Nostra slayings and large-scale cocaine dealing during a decades-long racketeering career with the Gambino crime family in New York and Florida. Gotti, son of the notorious late Gambino boss John Gotti, has shown himself a worthy heir to his father's nickname 'Teflon Don,' for his ability to elude serious convictions. Three previous trials have ended in hung juries. Seeking to extend that record, Gotti's lawyer, Charles Carnesi, insisted that his client had long bid farewell to crime. Carnesi accused the government of concocting a case based on testimony from convicted Mafia turncoats ready to say whatever was required in exchange for lighter sentences. 'The truth shouldn't be something that's for sale,' he said. Dressed in a dark suit, white shirt and black-rimmed reading glasses, Gotti Jr bore little resemblance to the vicious drug dealer, murderer and racketeer described by the government. His wife Kim, sisters Angel and Victoria, brother Peter, and several muscle- bound men were among the numerous supporters in the courtroom. Some walked out at the prosecutor's remarks. Most sat stony faced throughout. Gotti's mother, a stormy character who interrupted a previous session of the court with an expletive-loaded rant against the government, was not present. Carnesi concedes that his client was part of the Gambino network headed by his father, but says he mended his ways after pleading guilty in 1999 to racketeering and serving five years in prison. 'Everyone has free will. This isn't about the mob. This is about what you decide to do with your life,' Carnesi said. Carnesi then tore into the Mafia turncoats underpinning the government's case during the two-month trial. Carnesi stressed that each witness had committed horrific crimes, including multiple murders, kidnapping, drug dealing and extortion, and now stood to get reduced sentences in exchange for assisting the prosecution. The star prosecution witness, a confessed killer and former Gotti friend, John Alite, said on the witness stand that he literally could not remember how many crimes he had committed, Carnesi said. Testifying that Gotti had ordered him to commit murders was Alite's get out of jail card, Carnesi said. 'All he has to do is add the tag line 'John told me.'... Those few words wash away a multitude of sins.' The trial lifted the lid on New York's much depleted, but ultra-violent Cosa Nostra, where so-called soldiers, captains and bosses bear exotic names like Carmine 'The Bull' Agnello, Ronnie 'One Arm' Trucchio, and John 'Jackie Nose' D'Amico. The court battle also pitted attorneys with sharply different styles competing to persuade a jury that has seen infighting and the ejection of two members by Judge Kevin Castel. Carnesi, a squat man with a flamboyant manner and sharp suits, arrived at the start of the trial with Sun Tzu's classic 6th century BC treatise on military strategy, 'The Art of War.' On Monday, he used charm, sarcasm and indignation to defend a man he claims is being hounded by the FBI and prosecutors. But Trezevant, a wheelchair-bound prosecutor with a quiet, unflappable voice, insisted to jurors that Gotti is no paper tiger. In a steady tone he recounted gruesome details of what he said were Gotti's misdeeds, including the night he allegedly mocked 'Th-th-that's all folks,' in cartoon fashion, at a dying man. The Gambinos are one of the historic Five Families operating in the New York area. Gotti's father took over after the slaying of the previous Gambino don, Paul Castellano, outside Sparks Steak House in Manhattan in 1985. He was sentenced to life in prison in 1992 for racketeering, five murders and a long list of other serious crimes, making him the country's most notorious mobster. He died in prison in 2002. 