A former close friend of John Gotti Jr. who confessed to conspiring to kill three people was freed from jail after earning praise at his sentencing Friday for helping law enforcement jail 80 members of organized crime.

Authorities described the cooperation of 56-year-old Michael "Mikey Scars" DiLeonardo as revolutionary in the annals of mob history, saying it led to convictions that included 20 high-level, dangerous mobsters. He testified at 14 trials, including Gotti's, and investigators praised his encyclopedic knowledge of mob life. Gotti remains free after the government dropped its charges when juries repeatedly deadlocked at trials over several years.

U.S. District Judge John Koeltl in Manhattan cited the praise as he sentenced DiLeonardo to time served, freeing him after three years in custody, though he is likely to remain in the federal witness protection program for now.

Prior to the announcement of the sentence, DiLeonardo addressed the court, calling La Cosa Nostra a "living, breathing beast."

"I was born into an ideology. ... I was not a victim of it. I created victims for it," he said. DiLeonardo also apologized to society for himself and his forefathers, saying his family's life in organized crime goes back hundreds of years.

Assistant U.S. Attorney Elie Honig told Koeltl that DiLeonardo's cooperation was "nothing short of historic."

He said it was instrumental in bringing to justice "dangerous mobsters who had spent decades dodging the bullet of imprisonment."

He said those mobsters included many of organized crime's most influential leaders, forcing the Gambino family to scramble to refill its ranks.

Afterward, DiLeonardo shook hands and hugged law enforcement personnel throughout the courtroom. But he got a cold reception from Curtis Sliwa, the radio personality and Guardian Angels founder who was shot in a mob hit in 1992. The assailant was a masked gunman crouched in the front seat of a cab that was rigged to keep Sliwa from escaping.

"He could see I was cold as ice," Sliwa said of DiLeonardo's effort to include Sliwa in his celebration. "This guy had no problem planning a hit on me. ... He murdered three people. ... I will never forgive. I will never forget."

Authorities charged that Gotti ordered Sliwa's kidnapping to silence his daily on-air verbal assaults on Gotti's late father, Gambino boss John Gotti.

During one of the younger Gotti's trails, DiLeonardo testified that the elder Gotti had a child with a mistress, causing Gotti's widow to blame the testimony about the man known as the "Dapper Don" on "dirty government politics as usual."

He compared his relationship with the younger Gotti to that of the most notorious Gambino cooperator, Salvatore "Sammy the Bull" Gravano, who had been Gotti's father's confidant and his enforcer before he became a government witness.

The grandson of a gangster, DiLeonardo testified at trial that he committed three murders and "extorted everybody I could."

Gotti was in prison on a 1999 racketeering conviction when DiLeonardo was arrested and jailed in 2002. He testified that he was shocked to learn the Gambinos cut off his income and stripped him of his rank as captain.

After agreeing to cooperate and entering the witness protection program, he testified that he became so distraught by the thought of betraying his "brother John" that he tried to kill himself by overdosing on sleeping pills.

"John and I had a special bond in this life, and I always said I'd have undying loyalty to that man," he said. "I love that guy."