Joseph “Big Joey” Massino, the only mafia boss ever to become a government informant, is set to testify in the murder and racketeering trial of Vincent “Vinny Gorgeous” Basciano.

The New York Mafia has been weakened considerably over the past ten to twenty years by waves and waves of defections by wiseguys who ran into the arms of the federal government rather than endure lengthy sentences in prison.

Massino, once the feared boss of the Bonanno crime family, himself “flipped” in 2004 in order to avoid the death penalty – becoming the first ever official mob chieftain to do such a thing.

Facing a life sentence for his convictions on murder and racketeering charges, he also faced possible execution in another case.

At that time, Massino offered up information on Basciano, then an underling in the Bonanno clan, who was allegedly planning to kill a federal judge (which turned out to be Nicholas G. Garaufis of U.S. District Court, who, ironically, is presiding over the current trial)

Subsequently, Massino secretly tape-recorded conversations he had with Basciano in a federal holding cell.

In exchange for his cooperation, Massino pled guilty to eight other murders, received two consecutive life sentences, while his family was allowed to keep their homes and other property in Howard Beach, Queens.

Basciano, Massino’s successor as Bonanno boss, now himself faces the death penalty on charges he murdered associate Randolph Pizzolo. (Massino has also taped Basciano implicating him in Pizzolo’s killing).

Basciano is currently already serving a life sentence for a murder and racketeering conviction from 2007.

According to the New York Times, Barry Levin, the attorney who represented Basciano at the earlier trial, castigated Massino’s as “a pathological liar” and said the US government “had welcomed him with open arms only to prove they could break a boss.”

Levin also criticized the Justice Department for again prosecuting Basciano despite his life sentence in prison.

Massino was himself betrayed by his underboss and brother-in-law, Salvatore “Good Looking Sal” Vitale, in his earlier murder trial.

Immensely obese, Massino is now 68 years old. He was partially responsible for arranging one of the most spectacular Mafia hits in history – the execution of three Bonanno capos, Phillip Giaccone, Alphonse Sonny Red Indelicato and Dominick Big Trin Trinchera in May 1981. These three man were plotting to overthrow the Bonanno boss at the time, Phillip “Rusty” Rastelli.

The murders were dramatized in the film “Donnie Brasco” (although Massino himself was not portrayed in the movie).

A boss testifying against another boss is a sea change in the mob world, Thomas Reppetto, author of American Mafia, was quoted as saying.

The old-time bosses like [Lucky] Luciano and [Vito] Genovese are rolling in the graves. The Mafia as they knew it no longer exists.